Electrophotographic sensitive member

The present invention provides a high-capacity and high-quality electrophotographic sensitive member comprising an a-SiC photoconductive layer and an organic photosemiconductive layer piled up on an electrically conductive substrate in turn, characterized by that said a-SiC photoconductive layer is composed of elements, such as a Si element and a C element as well as a H element or a halogen element, and said a-SiC photoconductive layer comprises layer zones containing elements of the IIIa group or the Va group in the periodic table in a quantity within an appointed range.

FIELD OF THE INVENTION 
The present invention relates to an electrophotographic sensitive member 
comprising an amorphous silicon carbide photoconductive layer and an 
organic photosemiconductive layer piled up on said amorphous silicon 
carbide photoconductive layer. 
PRIOR ART 
Inorganic materials, such as Se, Se-Te, As.sub.2 Se.sub.3, ZnO, CdS and 
amorphous silicon, and various kinds of organic material have been used 
for photoconductive materials of electrophotographic sensitive members. Of 
them, Se has been practically used first, and also ZnO, CdS and amorphous 
silicon have been practically used then. On the other hand, of the organic 
materials, PVK-TNF has been practically used first, and then a separated 
function type sensitive member, in which separate materials take partial 
charge of a function of generating electrical charges and a function of 
transporting electrical charges, has been proposed, and the development of 
the organic materials for the organic photosemiconductive layer has made 
rapid progress on account of this separated function type sensitive 
member. 
On the other hand, also an electrophotographic sensitive member comprising 
an organic photosemiconductive layer piled up on the above described 
inorganic photoconductive layer has been proposed. 
For example, a built-up sensitive member comprising a Si-layer and an 
organic photosemiconductive layer has been already practically used but 
with this sensitive member, disadvantages have occurred in that Se itself 
is harmful and a sensitivity on a long wavelength side is inferior. 
So, a built-up sensitive member comprising an amorphous silicon carbide 
photoconductive layer and an organic photosemiconductive layer has been 
proposed in Japanese Patent Laid-Open No. Sho 56-14241. With this 
sensitive member, the above described points of problem were solved and 
the freedom from environmental pollution and the high photosensitive 
characteristics were obtained. 
The electrophotographic sensitive member according to the above described 
Japanese Patent Laid-Open has a construction comprising an amorphous 
silicon carbide layer expressed by a chemical formula of Si.sub.1-x 
C.sub.x H.sub.y (wherein 0&lt;x&lt;1, 0.05.ltoreq.y.ltoreq.0.2) and an organic 
photosemiconductive layer piled up on said amorphous silicon carbide 
layer. 
However, the inventors of the present invention have produced such the 
electrophotographic sensitive member and its photosensitivity, surface 
potential, residual potential and the like with the results that 
satisfactory characteristics have not been obtained yet and the further 
improvement is required. 
DISCLOSURE OF THE INVENTION 
Accordingly, the present invention has been achieved in view of the above 
described matters and it is an object of the present invention to provide 
an electrophotographic sensitive member capable of increasing the 
photosensitivity and charge acceptance and decreasing the residual 
potential. 
It is a first object of the present invention to provide an 
electrophotographic sensitive layer comprising an amorphous silicon 
carbide photoconductive layer (hereinafter amorphous silicon carbide is 
called a-SiC for short) and an organic photosemiconductive layer piled up 
on an electrically conductive substrate in this order, characterized by 
that a constituent element of said a-SiC photoconductive layer is a Si 
element, C element as well as a H element or halogen element and provided 
that the H element or halogen element is expressed by an A element and an 
elemental ratio of said layer is expressed by a composition formula of 
[Si.sub.1-x C.sub.x ].sub.1-y A.sub.y 0&lt;x&lt;0.5 and 0.2&lt;y&lt;0.5 are held good 
between x and y. 
A second invention of an electrophotographic sensitive member comprising an 
a-SiC photoconductive layer and an organic photosemiconductive layer piled 
up on an electrically conductive substrate in this order, characterized by 
that said a-SiC photoconductive layer comprises a first layer zone and a 
second layer zone, said first layer containing elements of the IIIa group 
(hereinafter called the IIIa group elements for short) in the periodic 
table in a quantity of 1 to 10,000 ppm and additionally a constituent 
element of said second layer zone being a Si element as well as a C 
element or a halogen element, and provided that an elemental ratio of said 
layer is expressed by a compositional formula of [Si.sub.1-x C.sub.x 
].sub.1-y A.sub.y x and y being set within a range of 0&lt;x&lt;0.5 and 
0.2&lt;y&lt;0.5, respectively. 
A third invention relates to an electrophotographic sensitive member 
comprising an a-SiC photoconductive layer and an organic 
photosemiconductive layer piled up on an electrically conductive substrate 
in this order, characterized by that said a-SiC photoconductive layer has 
a layer construction comprising a first layer zone and a second layer zone 
piled up in this order, said first layer zone containing the IIIa group 
elements in a quantity of 1 to 10,000 ppm, and said second layer zone 
containing the Va group elements in the periodic table (hereinafter called 
the Va group elements for short) in a quantity of 0 to 500 ppm. 
A fourth invention relates to an electrophotographic sensitive member 
comprising an a-SiC photoconductive layer and an organic 
photosemiconductive layer piled up on an electrically conductive substrate 
in this order, characterized by that a constituent element is a Si 
element, C element as well as H element or a halogen element, and provided 
that the H element or the halogen element is expressed by an A element and 
an elemental composition of said layer is expressed by a compositional 
formula of [Si.sub.1-x C.sub.x ].sub.1-y A.sub.y x and y being set within 
a range of 0&lt;x&lt;0.5 and 0.2&lt;y&lt;0.5, respectively, and further said layer 
containing the IIIa group elements in a quantity of 1 to 1,000 ppm. 
A fifth invention provides an electrophotographic sensitive member 
comprising an a-SiC photoconductive layer and an organic 
semiphotoconductive layer piled up on an electrically conductive substrate 
in this order, characterized by that said a-SiC photoconductive layer has 
a layer construction comprising a first layer zone and a second layer 
zone, said first layer zone containing the Va group elements in a quantity 
of 5,000 ppm or less, or said first layer zone substantially containing no 
Va group element but said second layer zone containing the IIIa group 
elements in a quantity of 1 to 1,000 ppm. 
A sixth invention provides an electrophotographic sensitive member 
comprising an a-SiC photoconductive layer and an organic 
photosemiconductive layer piled up on an electrically conductive 
substrate, characterized by that said a-SiC photoconductive layer has a 
layer construction comprising a first layer zone and a second layer zone, 
said first layer zone containing the Va group elements in a such a 
quantity that the largest content may be 10,000 ppm or less and the their 
content may be gradually reduced from the substrate to a surface of the 
sensitive member, and said second layer zone containing the IIIa group 
elements in a quantity of 1 to 1,000 ppm.

PREFERRED EMBODIMENTS OF THE INVENTION 
The present invention will be below described in detail. 
THE FIRST AND FOURTH INVENTIONS 
FIG. 1A shows a layer construction of an electrophotographic sensitive 
member according to the first and fourth inventions. Referring now to FIG. 
1A, an a-SiC photoconductive layer (2) and an organic photosemiconductive 
layer (3) piled up on an electrically conductive substrate (1) in this 
order. And, the a-SiC photoconductive layer (2) has a function of 
generating electric charges and the other organic photosemiconductive 
layer (3) has a function of transporting electric charges. 
And, in the case where an elemental ratio of the above described a-SiC 
photoconductive layer (2) is set within the following range in the first 
invention and an elemental ratio and a content of IIIa group elements are 
set within the following ranges in the fourth invention, a 
photosensitivity of the a-SiC photoconductive layer (2) itself can be 
remarkably increased, and preferably a sensitive member for use in 
positive electrification is obtained by the first invention and a 
sensitive member for use in negative electrification is obtained by the 
fourth invention, by that the first and fourth inventions are 
characterized. 
Compositional formula: 
EQU [Si.sub.1-x C.sub.x ].sub.1-y (1) 
wherein A is hydrogen or halogen. 
0&lt;x&lt;0.5, preferably 0.01&lt;x&lt;0.4 
0.2&lt;y&lt;0.5, preferably 0.25&lt;y&lt;0.45. 
Content of IIIa group elements: 1 to 1,000 ppm If the above described x 
value is 0.5 or more, the photoconductivity is remarkably reduced and the 
exciting function of photocarriers is reduced. 
In addition, if the y value is 0.2 or less, there is a tendency that the 
dark conductivity is increased. Furthermore, there is a tendency that the 
photoconductivity is reduced, whereby the desired photoconductivity can 
not be obtained, while, if the y value is 0.5 or more, the adhesion to the 
substrate is reduced, whereby the separation is apt to occur. 
Furthermore, as to the content of the above described IIIa group elements, 
if it is expressed by a mean value per the whole a-SiC layer and less than 
1 ppm, no improvement of photosensitivity is found while if it exceeds 
1,000 ppm, the dark conductivity is remarkably increased and a ratio of 
the photoconductivity to the dark conductivity is reduced, whereby the 
desired photosensitivity can not be obtained. 
Besides, in the case where it is used as the sensitive member for use in 
positive electrification, the above described content of Ilia group 
elements may be set within a range of 100 ppm or less. That is to say, if 
said content is set within said range, electron mobility of excited 
carriers is high, thereby positive charge charged on a surface of the 
sensitive member can be smoothly neutralized with the result that the 
photosensitivity can be enhanced. 
When the IIIa group elements are comprised in the a-SiC photoconductive 
layer (2), their doping distribution may be uniform or not uniform in a 
direction of layer thickness of the a-SiC photoconductive layer (2). If 
they are not uniformly doped, there may be layer zones comprising no IIIa 
group element in a part of said layer (2). In this case, the mean content 
of the IIIa group elements in the whole a-SiC layer comprising both the 
IIIa group element-containing a-SiC layer zones and the a-SiC layer zones 
without containing the IIIa group elements must be 1 to 1,000 ppm. 
Said IIIa group elements include B, Al, Ga, In and the like but B is 
desirable in respect of not only the superior covalent bond and the 
sensitive changeability of semiconductor characteristics but also the 
superior charging capacity and photosensitivity. 
In addition, also in the respective inventions which will be mentioned 
later, a B element is preferably used for the IIIa group elements. 
Besides, the above described a-SiC photoconductive layer (2) comprises a H 
element and a halogen element for ends of dangling bonds but the H element 
is desirable in respect of the easy incorporation thereof into the end, 
whereby the density of the localized state in the band gap is reduced. 
A thickness of the a-SiC photoconductive layer (2) is set within a range of 
0.05 to 5 microns, preferably 0.1 to 3 microns. If said thickness is set 
within said range, the photosensitivity is increased and the residual 
potential is reduced. 
Said substrate (1) includes metallic conductors formed of copper, brass, 
SUS,Al and the like or insulators, such as glass and ceramics, of which 
surface is coated with an electrically conductive thin film. Above all, Al 
is advantageous in respect of economy and adhesion to the a-SiC layer. 
In addition, the electrophotographic sensitive member according to the 
present invention can correspond to the negative electrification type or 
the positive electrification type by the selection of materials of the 
organic photosemiconductive layer (3). That is to say, in the case of the 
negative electrification type electrophotographic sensitive member, the 
organic photosemiconductive layer (3) is formed of electron donor 
compounds, while, in the case of the positive electrification type 
electrophotographic sensitive member, the organic photosemiconductive 
layer (3) is formed of electron acceptor compounds. 
Said electron doner compounds include high molecular compounds, such as 
poly-N-vinyl carbazol, polyvinyl ptrene, polyvinyl anthracene and 
pyreneformaldehyde condensation polymer, and low molecular compounds, such 
as oxadiazol, oxazol, pyrazoline, tripheny methane, hydrazone, triaryl 
amine, N-phenyl carbazol and stylbene. Said low molecular compounds are 
used in the form of suspension thereof in binders such as polycarbonate, 
polyester, methacrylic resin, polyamide resin, acryl epoxy resin, 
polyethylene resin, phenolic resin, polyurethane resin, butylal resin, 
polyvinyl acetate resin and urea resin. 
Said electron acceptor compounds include 2, 4, 7-trinitrofluorenon and the 
like. 
Thus, according to the first and fourth inventions, the photoconductivity, 
which is superior to that of the electrophotographic sensitive member 
proposed by Japanese Patent Laid-Open No. Sho 56-14241, can be obtained 
and suitable for the positive electrification and the negative 
electrification. 
FIG. 1(B) shows layer constructions of the electrophotographic sensitive 
members according to the second, third, fifth and sixth inventions. In any 
one of the second, third, fifth and sixth inventions, the a-SiC 
photoconductive layer (2) comprises a first layer zone (2a) and a second 
layer zone (2b) piled up therein in this order differently from that in 
the first and fourth inventions. 
The present invention is characterized by that the first and second layer 
zones (2a), (2b) contain the IIIa group elements or the Va group elements 
in an appointed quantity to improve the photosensitivity, charge 
acceptance or residual potential. 
In addition, the present invention is also characterized by that the 
electrophotographic sensitive members according to the second and third 
inventions are suitable for the positive electrification while the 
electrophotographic sensitive members according to the fifth and sixth 
inventions are suitable for the negative electrification. 
At first, the sensitive member for use in positive electrification will be 
described. 
SECOND INVENTION 
The second invention is characterized by that the a-SiC photoconductive 
layer (2) comprises the first layer zone (2a) and the second layer zone 
(2b) piled up therein in this order, the first layer zone (2a) containing 
the IIIa group elements in a quantity within an appointed range, and an 
elemental ratio of the second layer zone (2b) being set within an 
appointed range, whereby improving the charge acceptance in comparison 
with the first invention. 
The second layer zone (2b) has a substantial function of generating 
photocarriers and if its elemental ratio is set by the compositional 
formula (1), the photosensitivity of this layer zone itself can be 
remarkably enhanced. Its reason is above described relating to the 
compositional formula (1). 
A thickness of such the second layer zone (2b) is set within a range of 
0.05 to 5 microns, preferably 0.1 to 3 microns. With the thickness within 
such the range, the photosensitivity can be increased and the residual 
potential can be reduced. 
On the other hand, the first layer zone (2a) contains the IIIa group 
elements in a quantity of 1 to 10,000 ppm, preferably 500 to 5,000 ppm, 
whereby, of the photocarriers generated in the second layer zone (2b), 
positive charges can be smoothly flown toward the substrate side while the 
carriers on the substrate side, that is, negative charges induced on the 
substrate side can be prevented from being flown into the second layer 
zone (2b). That is to say, it can be said in respect of the rectification 
property of the first layer zone (2a) for the substrate (1) that the 
former is brought into a non-ohmic contact with the latter. Accordingly, 
this non-ohmic contact leads to the enhanced charge acceptance. 
Besides, in the case where the content of the IIIa group elements is not 
uniform in the direction of layer thickness of the first layer zone it is 
expressed by a mean value thereof. 
If such the content of the IIIa group elements is less than 1 ppm, the 
function of preventing the carriers from being injected from the substrate 
is reduced, whereby the charge acceptance is not enhanced, while, if it 
exceeds 10,000 ppm, the internal defects in this layer zone are increased 
to deteriorate the quality of film, whereby the charge acceptance is 
reduced and the residual potential is enhanced. 
In addition, it is desired that the first layer zone (2a) is more 
concretely set in not only the content of the IIIa group elements but also 
the thickness. 
That is to say, it is desired that the thickness of the first layer zone 
(2a) is set within a range of 0.1 to 5 microns, preferably 0.5 to 3 
microns. The setting of the thickness of the first layer zone (2a) within 
such the range leads to an advantage in that not only the residual 
potential can be reduced but also the voltage-resistance of the sensitive 
member can be enhanced. 
In addition, it is desired that the content of the IIIa group elements, 
thickness and compositional ratio of SiC of the first layer zone (2a) are 
set as follows: 
That is to say, provided that the compositional ratio of SiC is expressed 
by the compositional formula Si.sub.1-x C.sub.x it is desired that 
0.1&lt;x&lt;0.5 holds good. Thereupon, the charge acceptance can be enhanced and 
the adhesion to the substrate can be enhanced. 
In addition, when the ratio of C element is set in the above described 
manner, it is desired that said ratio is larger in comparison with that in 
the second layer zone (2b). Thereupon, an advantage occurs in that the 
charge acceptance can be enhanced and the adhesion to the substrate can be 
enhanced. 
Thus, with the electrophotographic sensitive member according to the second 
invention, of the carriers generated in the a-SiC photoconductive layer 
(2), negative charges are directed to the organic photosemiconductive 
layer (3) while positive charges to the substrate (1). Accordingly, the 
positive electrification type electrophotographic sensitive member is 
obtained. 
THIRD INVENTION 
The third invention is characterized by that the a-SiC photoconductive 
layer (2) comprises the first layer zone (2a) and the second layer zone 
(2b) piled up therein in this order, the first layer zone (2a) containing 
the IIIa group elements in a quantity within an appointed range, and the 
second layer zone (2b) containing the Va group elements in a quantity 
within an appointed range, whereby improving the photoconductivity in 
comparison with that in the second invention. 
It is desired that the a-SiC photoconductive layer (2) comprises an 
amorphous Si element and an amorphous C element as well as a hydrogen 
element or a halogen element introduced into an end portion of a dangling 
bond of said Si element and C element and its compositional formula is 
expressed by the above described formula (1). 
Next, the first layer zone (2a) contains the IIIa group elements in a 
quantity of 1 to 10,000 ppm, preferably 500 to 5,000 ppm, whereby the 
p-type semiconductor is obtained, of photocarriers generated in the a-SiC 
photoconductive layer (2), positive charges being able to be smoothly 
flown toward the substrate side while carriers on the substrate side can 
be prevented from being flown into the a-SiC photoconductive layer (2). 
That is to say, it can be said in respect of the rectification property of 
the first layer zone (2a) for the substrate (1) that the former is brought 
into a non-ohmic contact with the latter. 
Accordingly, this non-ohmic contact leads to the enhanced charge 
acceptance. 
In addition, if the content of the IIIa group elements in the first layer 
zone (2a) is not uniform in the direction of layer thickness of the first 
layer zone (2a), it is expressed by its mean value. 
If the content of the IIIa group elements is less than 1 ppm, the function 
of preventing the carriers from being injected into the first layer zone 
(2a) from the substrate, whereby the charge acceptance is not enhanced, 
while, if said content exceeds 10,000 ppm, the internal defects in this 
layer zone are increased to deteriorate the film quality, whereby the 
charge acceptance is reduced and the residual potential is increased. The 
present inventors confirmed that the desirable range of the above 
described content of the IIIa group elements is 500 to 5,000 ppm and at 
this time both characteristics of the charge acceptance and the 
photosensitivity are improved. 
In addition, it is desired that the first layer zone (2a) is more 
concretely set in not only content of the IIIa group elements but also 
thickness. 
That is to say, the thickness of the first layer zone (2a) is set within a 
range of 0.05 to 5 microns, preferably 0.1 to 3 microns, and the setting 
of the thickness of the first layer zone (2a) within the above described 
range leads to an advantage that the residual potential can be reduced and 
the voltage resistance of the sensitive member can be enhanced. 
Besides, it is desirable that the first layer zone (2a) is set in 
compositional ratio of SiC as follows in addition to content of the IIIa 
group elements and thickness. 
That is to say, if the compositional ratio of SiC is expressed by the 
compositional formula Si.sub.1-x C.sub.x it is desirable that 0.1&lt;x&lt;0.5 
holds good, and at this time the charge acceptance and the adhesion to the 
substrate can be enhanced. 
Furthermore, when the ratio of C element is set in the above described 
manner, it is desirable that said ratio is larger than that in the second 
layer zone (2b), and at this time an advantage occurs in that the charge 
acceptance and the adhesion to the substrate can be enhanced. 
The second layer zone (2b) contains the Va group elements in a quantity of 
0 to 500 ppm, preferably 0 to 100 ppm, and at this time the n-type 
semiconductor layer is formed on the side of the organic 
photosemiconductive layer (3) within the a-SiC photoconductive layer (2) 
to be able to smoothly flow the photocarriers, in particular the negative 
charges, generated in said layer (2) toward the organic 
photosemiconductive layer (3), whereby enhancing the photosensitivity. In 
addition, the above described content of the Va group elements of 
expresses the substantial absence of the Va group elements and this is 
excluded in the third invention. 
In addition, if the content of the Va group elements in the second layer 
zone (2b) is not uniform in the direction of layer thickness of the second 
layer zone (2b), said content is expressed by a mean value. 
If such the content of the Va group elements exceeds 500 ppm, the 
capability of generating photoexcited carriers is reduced and the 
photosensitivity is reduced. 
Furthermore, it is desirable that the second layer zone (2b) is more 
concretely set in not only content of the Va group elements but also 
thickness. 
That is to say, it is desirable that the thickness is set within a range of 
0.05 to 5 microns, preferably 0.1 to 3 microns, and at this time the 
photosensitivity is enhanced and the residual potential is reduced. 
The above described Va group elements include N, P, As, Sb and Bi but P is 
preferably used in respect of its superior covalent bond and sensitive 
chargeability of semiconductor characteristics as well as superior 
chargeability and photosensitivity. In addition, also in the respective 
inventions, which will be mentioned later, it is desirable that the P 
element is used as the Va group elements. 
Thus, with the electrophotographic sensitive member according to the third 
invention, a p-n junction is formed in the a-SiC photoconductive layer 
(2), whereby, of carriers generated in this layer (2), negative charges 
are directed toward the organic photosemiconductive layer (3), while, 
positive charges are directed toward the substrate (1), whereby obtaining 
the electrophotographic sensitive member of positive charge type. 
In addition, the above described p-n junction construction led to the 
remarkable improvement of photosensitivity in comparison with the second 
invention. 
In the electrophotographic sensitive member according to the third 
invention the content of the Ilia group elements in the first layer zone 
(2a) and the content of the Va group elements in the second layer zone 
(2b) may be changed in the direction of layer thickness of the first layer 
zone (2a) and the second layer zone (2b). It is illustrated in FIGS. 7 to 
12 and FIGS. 17 and 78. 
Referring to these drawings, an axis of abscissa designates a direction of 
layer thickness, d designating a boundary surface of the substrate (1) and 
the first layer zone (2a), a designating a boundary surface of the first 
layer zone (2a) and the second layer zone (2b), e designating a boundary 
surface of the second layer zone (2b) and the organic photosemiconductive 
layer (3), and an axis of ordinate designating a content of the IIIa group 
elements or the Va group elements. 
When the content of the IIIa group elements in the first layer zone (2a) 
and the content of the Va group elements in the second layer zone (2b) are 
changed in the direction of layer thickness, said contents correspond to a 
mean content per the whole respective layer zones (2a), (2b). 
In addition, when the content of the IIIa group elements and the content of 
the Va group elements are changed in the above described manner, a 
intrinsic semiconductor layer is formed between the first layer zone (2a) 
and the second layer zone (2b) according to circumstances. 
Furthermore, according to the third invention, the first layer zone (2a) 
may contain the IIIa group elements so that the maximum content may be 1 
to 10,000 ppm, preferably 500 to 5,000 ppm, and their doping distribution 
may be gradually reduced in the direction of layer thickness from the 
substrate to the surface of the sensitive member. Also this leads to the 
formation of the p-type semiconductor and of the photocarriers generated 
in the a-SiC photoconductive layer (2), in particular the positive charges 
can be smoothly flown toward the substrate side and the carriers on the 
substrate side can be prevented from being flown into the a-SiC 
photoconductive layer (2). That is to say, it can be said in respect of 
the rectification property of the first layer zone (2a) for the substrate 
(1) that the former is brought into non-ohmic contact with the latter. 
And, such the non-ohmic contact leads to a still more reduced residual 
potential. 
If the first layer zone (2a) is expressed by the largest content of the 
IIIa group elements in such the manner, in the case where this largest 
content is less than 1 ppm, the function of preventing the carriers from 
being injected from the substrate is reduced, whereby the charge 
acceptance is not enhanced, while, in the case where it exceeds 10,000 
ppm, the internal defects in this layer zone are increased to reduce the 
film quality, whereby reducing the charge acceptance and increasing the 
residual potential. 
Also in the case where the doping distribution of the IIIa group elements 
in the first layer zone (2a) is gradually reduced in the direction of 
layer thickness from the substrate toward the surface of the sensitive 
member, as above described, both the content of the IIIa group elements in 
the first layer zone (2a) and the content of the Va group elements in the 
second layer zone (2b) may be changed in the direction of layer thickness. 
Its examples are shown in FIGS. 19 to 23. 
Referring to these drawings, an axis of abscissa designates a direction of 
layer thickness, d designating a boundary surface of the substrate (1) and 
the first layer zone (2a), a designating a boundary surface of the first 
layer zone (2a) and the second layer zone (2b), e designating a boundary 
surface of the second layer zone (2b) and the organic photosemiconductive 
layer (3), and an axis of ordinate designating a content of the IIIa group 
elements or the Va group elements. 
FIFTH INVENTION 
The fifth invention is characterized by that the a-SiC photoconductive 
layer (2) comprises the first layer zone (2a) and the second layer zone 
(2b) piled up in this order therein, the first layer zone (2a) containing 
the Va group elements in a quantity within an appointed range or 
substantially no containing the Va group elements, and the second layer 
zone (2b) containing the IIIa group elements in a quantity within an 
appointed range, whereby improving the charge acceptance in comparison 
with that in the fourth invention. 
At first, it is desirable that the a-SiC photoconductive layer (2) 
comprises an amorphous Si element and an amorphous C element as well as a 
H element or a halogen element introduced into an end portion of a 
dangling bond of said amorphous Si element and said amorphous C element 
and its composition is set so that said compositional formula (1) may hold 
good. 
The first layer zone (2a) contains the Va group elements in a quantity of 0 
to 5,000 ppm (0 ppm means the substantial absence of the Va group 
elements), preferably 0 to 3,000 ppm, whereby obtaining a n-type 
semiconductor, being able to smoothly flow photocarriers, in particular 
negative charges, generated in the a-SiC photoconductive layer (2) toward 
the substrate side, and being able to prevent carriers on the substrate 
side from being flown into the a-SiC photoconductive layer (2). That is to 
say, it can be said in respect of the rectification property of the first 
layer zone (2a) for the substrate (1) that the former is brought into 
non-ohmic contact with the latter. 
Accordingly, this non-ohmic contact leads to the enhanced charge 
acceptance. 
If the content of the Va group elements exceeds 5,000 ppm, the internal 
defects in this layer zone are increased to reduce the film quality, 
whereby reducing the charge acceptance and increasing the residual 
potential. 
In addition, it is desirable that the first layer zone (2a) is more 
concretely set in thickness in addition to content of the Va group 
elements. 
That is to say, it is desirable that the thickness of the first layer zone 
(2a) is set within a range of 0.05 to 5 microns, preferably 0.1 to 3 
microns, At this time, an advantage occurs in that not only the residual 
potential can be reduced but also the voltage resistance of the sensitive 
member can be increased. 
Moreover, it is desirable that the first layer zone (2a) is set in 
compositional ratio of SiC as follows in addition to content of the Va 
group elements and thickness. 
That is to say, if the composition of the first layer zone (2a) is 
expressed by the compositional formula Si.sub.1-x C.sub.x it is desirable 
that 0.1&lt;x&lt;0.5 holds good. At this time, the charge acceptance and the 
adhesion to the substrate can be enhanced. 
In addition, it is desirable that when the ratio of the C element is set in 
the above described manner, it is increased in comparison with that in the 
second layer zone (2b). At this time, an advantage occurs in that the 
charge acceptance and adhesion to the substrate can be enhanced. 
The second layer zone (2b) contains the IIIa group elements in a quantity 
of 1 to 1,000 ppm, preferably 30 to 300 ppm, whereby a p-type 
semiconductor layer is formed on the side of the organic 
photosemiconductive layer (3) within the a-SiC photoconductive layer (2) 
and photocarriers, in particular positive charges, generated in this layer 
(2) can be smoothly flown into the organic photosemiconductive layer (3). 
As a result, the photosensitivity is enhanced and the residual potential 
is reduced. 
Such the content of the IIIa group elements is less than 1 ppm, the 
photosensitivity can not be sufficiently improved, while, if it exceeds 
1,000 ppm, the capacity of generating photoexcited carriers is reduced and 
the photosensitivity is reduced. 
In addition, it is desirable that the second layer zone (2b) is more 
concretely set in thickness in addition to content of the IIIa group 
elements. 
That is to say, it is desirable that the thickness of the second layer zone 
(2b) is set within a range of 0.05 to 5 microns, preferably 0.1 to 3 
microns. At this time, the photosensitivity is enhanced and the residual 
potential is reduced. 
Accordingly, with the electrophotographic sensitive member according to the 
fifth invention, the p-n junction is formed in the a-SiC photoconductive 
layer (2) and of carriers generated in this layer (2), positive charges 
are directed toward the organic photosemiconductive layer (3) while 
negative charges are directed toward the substrate (1). Accordingly, the 
electrophotographic sensitive member of negatively charged type is 
obtained. 
In addition, the above described p-n junction leads to a remarkable 
improvement of the charge acceptance in comparison with that in the fourth 
invention. 
In the electrophotographic sensitive member according to the fifth 
invention the content of the Va group elements in the first layer zone 
(2a) and the content of the IIIa group elements in the second layer zone 
(2b) may be changed in the direction of layer thickness. Its examples are 
shown in FIGS. 7 to 16. 
Referring to these drawings, an axis of abscissa designates a direction of 
layer thickness, d designating a boundary surface of the substrate and the 
first layer zone (2a), a designating a boundary surface of the first layer 
zone (2a) and the second layer zone (2b), e designating a boundary surface 
of the second layer zone (2b) and the organic photosemiconductive layer 
(3), and an axis of ordinate designating a content of the Va group 
elements or the IIIa group elements. 
When the content of the Va group elements in the first layer zone (2a) and 
the content of the IIIa group elements in the second layer zone (2b) are 
changed in the direction of layer thickness in the above described manner, 
said contents correspond to mean values per the respective whole layer 
zones (2a), (2b). 
In addition, in the case where the content of the Va group elements is 
changed in the above described manner, a intrinsic semiconductive layer is 
formed between the first layer zone (2a) and the second layer zone (2b) 
according to circumstances. 
SIXTH INVENTION 
The sixth invention is characterized by that the a-SiC photoconductive 
layer (2) comprises the first layer zone (2a) and the second layer zone 
(2b) formed therein in this order, the first layer zone (2a) containing 
the Va group elements in a quantity within an appointed range, and the 
second layer zone (2b) containing the IIIa group elements in a quantity 
within an appointed range, whereby improving the charge acceptance and 
photosensitivity in comparison with the fifth invention. 
At first, it is desirable that the a-SiC photoconductive layer (2) 
comprises an amorphous Si element and an amorphous C element as well as a 
H element or a halogen element introduced into an end portion of a 
dangling bond of said Si element and said C element and its composition is 
expressed by said compositional formula (1). 
Next, the first layer zone (2a) contains the Va group elements so that 
their maximum content may be 0 to 10,000 ppm (excluding 0), preferably 0 
to 3,000 ppm, and their doping distribution is gradually reduced in the 
direction of layer thickness from the substrate toward the surface of the 
sensitive member, whereby a n-type semiconductor is formed and of 
photocarriers generated in the a-SiC photoconductive layer (2), negative 
charges can be smoothly flown toward the substrate side while carriers on 
the substrate side can be prevented from being flown into the a-SiC 
photoconductive layer (2). That is to say, it can be said in respect of 
the rectification property of the first layer zone (2a) for the substrate 
(1) that the former is brought into non-ohmic contact with the latter. 
And, this non-ohmic contact leads to the still more reduced residual 
potential. 
In addition, when the first layer zone (2a) is expressed by the largest 
content of the Va group elements, if this largest content exceeds 10,000 
ppm, the internal defects in this layer zone are increased to reduce the 
film quality, whereby the charge acceptance is reduced and the residual 
potential is increased. 
Besides, it is desirable that the first layer zone (2a) is more concretely 
set in thickness in addition to largest content of the Va group elements. 
That is to say, it is desirable that the thickness of the first layer zone 
(2a) is set within a range of 0.05 to 5 microns, preferably 0.1 to 3 
microns. At this time, an advantage occurs in that the residual potential 
can be reduced and the voltage resistance of the sensitive member can be 
enhanced. 
In addition, it is desirable that the first layer zone (2a) is set in 
compositional ratio of SiC as follows in addition to largest content of 
the Va group elements and thickness. 
That is to say, when it is expressed by the compositional formula 
Si.sub.1-x C.sub.x it is desirable that 0.1&lt;x&lt;0.5 holds good. At this 
time, the charge acceptance and the adhesion to the substrate can be 
enhanced. 
In addition, it is desirable that said ratio is larger than that in the 
second layer zone (2b) when the ratio of C element is set in the above 
described manner. At this time, an advantage occurs in that the charge 
acceptance and the adhesion to the substrate can be enhanced. 
The second layer zone (2b) contains the IIIa group elements in a quantity 
of 1 to 1,000 ppm, preferably 3 to 300 ppm, whereby a p-type 
semiconductive layer is formed on a side of the organic 
photosemiconductive layer (3) in the a-SiC photoconductive layer (2), and, 
of carriers generated in this layer (2), positive charges can be smoothly 
flown toward the organic photosemiconductive layer (3), and as a result, 
the photosensitivity is enhanced and the residual potential is reduced. 
In addition, when the content of the Ilia group elements in the second 
layer zone (2b) is not uniform in the direction of layer thickness of the 
second layer zone (2b), it is expressed by a mean value. 
If such the content of the Ilia group elements is less than 1 ppm, the 
photosensitivity can not be sufficiently improved, while, if it exceeds 
1,000 ppm, the capacity of generating photoexcited carriers and the 
photosensitivity are reduced. 
In addition, it is desirable that the second layer zone (2b) is more 
concretely set in thickness in addition to content of the Ilia group 
elements. 
That is to say, it is desirable that the thickness of the second layer zone 
(2b) is set within a range of 0.05 to 5 microns, preferably 0.1 to 3 
microns. At this time, the photosensitivity is enhanced and the residual 
potential is reduced. 
Thus, with the electrophotographic sensitive member according to the sixth 
invention, a p-n junction is formed in the a-SiC photoconductive layer 
(2), and, of carriers generated in this layer (2), positive charges are 
directed toward the organic photosemiconductive layer (3) while negative 
charges are directed toward the substrate (1). Accordingly, the negative 
charge type electrophotographic sensitive member is obtained. 
In addition, such the p-n junction leads to a remarkable reduction of 
residual potential in comparison with that in the fifth invention. 
Besides, in the electrophotographic sensitive member according to the sixth 
invention both the content of the Va group elements in the first layer 
zone (2a) and the content of the IIIa group elements in the second layer 
zone (2b) may be changed in the direction of layer thickness. Its examples 
are shown in FIGS. 19 to 23. 
Referring to these drawings, an axis of abscissa designates a direction of 
layer thickness, d designating a boundary surface of the substrate and the 
first layer zone (2a), a designating a boundary surface of the first layer 
zone (2a) and the second layer zone (2b), e designating a boundary surface 
of the second layer zone (2b) and the organic photosemiconductive layer 
(3), and an axis of ordinate designating a content of the Va group 
elements or the IIIa group elements. 
When the content of the Va group elements in the first layer zone (2a) and 
the content of the IIIa group elements in the second layer zone (2b) are 
changed in the direction of layer thickness, said contents correspond to 
the respective mean values per the respective whole layer zones (2a), 
(2b). 
As above described, the electrophotographic sensitive member according to 
the present invention could be developed as the second to sixth inventions 
by setting the doping by the Va group elements and/or the IIIa group 
elements of the a-SiC photoconductive layer (2) within the appointed 
range. 
Next, according to the present invention, the content of C element may be 
changed in the direction of layer thickness of the a-SiC photoconductive 
layer (2). 
For example, as to the electrophotographic sensitive members according to 
the second to sixth inventions, a layer zone containing a large quantity 
of C element may be formed between the second layer zone (2b) and the 
organic photosemiconductive layer (3), as shown in FIG. 1C. At this time, 
a difference between the second layer zone (2b) and the organic 
photosemiconductive layer (3) in dark conductivity is remarkably reduced, 
whereby the carriers are difficult to be trapped on the boundary surface 
of both layers (2b), (3). 
That is to say, the dark conductivity of the second layer zone (2b) is 
about 10.sup.-11 to 10.sup.-13 (ohm.multidot.cm).sup.-1 while that of the 
organic photosemiconductive layer (3) is about 10.sup.-14 to 10.sup.-15 
(ohm.multidot.cm).sup.-1. Accordingly, the carriers generated in the 
second layer zone (2b) are apt to be smoothly flown toward the organic 
photosemiconductive layer (3) due to such a great difference of dark 
conductivity. Consequently, the present inventors have found that the 
formation of the layer zone (2c) containing a large quantity of C element 
leads to a reduced dark conductivity of this layer zone (2c) and a reduced 
difference between both layers (2c), (3), whereby both characteristics of 
the photosensitivity and the residual potential can be improved. 
Such the layer zone (2c) containing a large quantity of C element is 
expressed by a ratio of C element contained and a thickness as follows: 
The ratio of C element contained is a value of x in Si.sub.1-x C.sub.x and 
it is desirable that x is set within a range of 0.2 to 0.5, preferably 0.3 
to 0.5. If the value of x is less than 0.2, the difference between both 
layers (2b), (3) in dark conductivity can not be reduced in a desired 
manner, whereby the characteristics of photosensitivity and residual 
potential can not be improved, while, if the value of x is 0.5 or more, 
the carriers are apt to be trapped in the layer zone (2c) containing a 
large quantity of C element and the photosensitivity characteristics are 
reduced. 
In addition, it is desirable that the thickness of the layer zone (2c) 
containing a large quantity of C element is set within a range of 10 to 
2,000 .ANG., preferably 500 to 1,000 .ANG.. There is a tendency that if 
the thickness is less than 10 .ANG., the characteristics of 
photosensitivity and residual potential can not be improved, while, if it 
exceeds 2,000 .ANG., the residual potential is increased. 
The content of C element of such the second layer zone (2b) and the layer 
zone (2c) containing a large quantity of C element may be changed in the 
direction of layer thickness. Its examples are shown in for example FIGS. 
24 to 29. Referring to these drawings, an axis of abscissa designates a 
direction of layer thickness, a designating a boundary surface of the 
first layer zone (2a) and the second layer zone (2b), b designating a 
boundary surface of the second layer zone (2b) and the layer zone (2c) 
containing a large quantity of C element, c designating a boundary surface 
of the layer zone (2c) containing a large quantity of C element and the 
organic photosemiconductive layer (3), and an axis of ordinate designating 
a content of C element. 
In addition, when the content of C element in the second layer zone (2b) or 
the layer zone (2c) containing a large quantity of C element is changed in 
the direction of layer thickness, the ratio of C element contained (the 
value of x) corresponds to mean ratios of C element contained per the 
respective whole layer zones (2b), (2c). 
PRODUCTION METHODS ACCORDING TO THE PRESENT INVENTION 
Thin-film forming methods, such as glow discharge decomposition method, ion 
plating method, reactive sputtering method, vacuum vapor deposition method 
and CVD method, have been used as a method of forming an a-SiC layer. In 
the case where the glow-discharge decomposition method is used, a Si 
element-containing gas is combined with a C element-containing gas and the 
resulting mixture gas is subjected to a plasma decomposition to form a 
film. Said Si element-containing gas includes SiH.sub.4, Si.sub.2 H.sub.6, 
Si.sub.3 H.sub.8, SiF.sub.4, SiCl.sub.4, SiHCl.sub.3 and the like while 
said C element-containing gas includes CH.sub.4, C.sub.2 H.sub.2, C.sub.3 
H.sub.8 and the like but above all C.sub.2 H.sub.2 is desirable in 
respect of the speedy film formation. 
In addition, in the case where the C.sub.2 H.sub.2 gas and the Si 
element-containing gas are subjected to the glow-discharge decomposition 
in combination to form the a-SiC layer, the film-forming speed is reduced 
or increased by changing a flow rate of gases, a mixture ratio of gases, a 
high-frequency electric power and the like. However, even in the case 
where the film-forming speed is reduced, the film-forming speed, which is 
sufficiently high in comparison with that in the use of other C 
element-containing gases, can be obtained. 
It could be confirmed from the repeated experiments by the present 
inventors that comparing at the same C element-content, the a-SiC 
photoconductive layer obtained at the reduced film-forming speed was 
superior to that obtained at the increased film-forming speed in 
photoconductive characteristic. 
However, also the a-SiC photoconductive layer obtained at the increased 
film-forming speed has sufficient photoconductive characteristics. 
The glow-discharge decomposition apparatus used in the present preferred 
embodiments is described with reference to FIG. 2 illustrating one example 
thereof. 
Referring to FIG. 2, a first tank (4), a second tank (5), a third tank (6), 
a fourth tank (7) and a fifth tank (8) comprises a SiH.sub.4 gas, a 
C.sub.2 H.sub.2 gas, a PH.sub.3 gas, B.sub.2 H.sub.6 gas (the PH.sub.3 gas 
and the B.sub.2 H.sub.6 gas are all diluted with a hydrogen gas) and 
H.sub.2 in a leaktight manner, respectively. These gases are discharged by 
opening the respective corresponding first adjusting valve (9), a second 
adjusting valve (10), a third adjusting valve (11), a fourth adjusting 
valve (12) and a fifth adjusting valve (13). Flow rates of the discharged 
gases are controlled by the respective mass flow controllers (14), (15), 
(16), (17), (18) and the respective gases are mixed to be sent to a main 
pipe (19). In addition, reference numerals (20), (21) designate a stop 
valve. 
The gas passing through the main pipe (19) is flown into a reaction tube 
(22) but said reaction tube (22) is provided with a capacitively couple 
type discharge electrode (231 disposed therein, a cylindrical film-forming 
substrate (24) being placed on a substrate-supporting member (25), and 
said substrate-supporting member (25) being rotatably driven by means of a 
motor (26), whereby the the substrate (24) is rotated. And, a 
high-frequency electric power having an electric power of 50 w to 3 Kw and 
a frequency of 1 to 50 MHz is applied to the electrode (23) and the 
substrate (24) is heated to about 200.degree. to 400.degree. C., 
preferably about 200.degree. to 350.degree. C., by means of a suitable 
heating means. 
In addition, the reaction tube (22) is connected to a rotary pump (27) and 
a diffusion pump (28), whereby a depressed condition (a gas pressure 
during the discharge of 0.01 to 2.0 Tort), which is required during the 
film-formation, can be maintained. 
In the case where for example a P element containing a-SiC layer is formed 
on the substrate (24) by the use of the glow-discharge decomposition 
apparatus having such the construction, the adjusting valve (9), the 
second adjusting valve (10), the third adjusting valve (11) and the fifth 
adjusting valve (13) are opened to discharge the SiH.sub.4 gas, the 
C.sub.2 H.sub.2 gas, the PH.sub.3 gas and the H.sub.2 gas, respectively, 
and the discharged quantities of said gases are controlled by means of the 
mass flow controllers (14), (15), (16) and (18), respectively. The 
respective gases are mixed and the resulting mixture gas is flown into the 
reaction tube (22) through the main pipe (19). And, upon setting the 
vacuousity within the reaction tube, the substrate temperature and the 
high-frequency electric power applied to the electrode at appointed 
conditions, the glow-discharge is generated and the gas is decomposed to 
form the P element-containing a-SiC film on the substrate at a high speed. 
After the a-SiC layer is formed by the above described thin-film forming 
method, the organic photosemiconductive layer is formed. 
The organic photosemiconductive layer is formed by the dipping method or 
the coating method. The former is a method in which a sensitive material 
is dipped in a dispersion of coating agents in solvents and then pulled up 
at a constant speed followed by subjecting to the natural dehydration and 
the thermal aging (about one hour at about 150.degree. C.). In addition, 
according to the latter coating method, a sensitive material dispersed in 
a solvent is applied by the use of a coater and then the thermal 
dehydration is carried out. 
The present invention will be below described with reference to the 
preferred embodiments. 
EXAMPLE 1 
The a-SiC film (having a film-thickness of about 1 micron) was formed by 
the glow-discharge in the glow-discharge decomposition apparatus shown in 
FIG. 2 with setting a flow rate Of the SiH.sub.4 gas at 200 sccm, a flow 
rate of the H.sub.2 gas at 270 sccm, the gas pressure at 0.6 Tort, the 
high-frequency electric power at 150 W and the substrate temperature at 
250.degree. C. but changing a flow rate of the C.sub.2 H.sub.2 gas. 
The C-content of the a-SiC film was changed in such the manner and a 
quantity of C in the film was measured by the XMA method and in addition 
the the photoconductivity and the dark conductivity were measured with the 
results as shown in FIG. 3. 
Referring to FIG. 3, an axis of abscissa designates the C-content, that is, 
the value of x in Si.sub.1-x C.sub.x an axis of ordinate designating the 
conductivity, .smallcircle. marks designating a plot of the 
photoconductivity for an exposure wavelength of 550 nm (luminous quantity: 
50 micronW/cm.sup.2), marks designating a plot of the dark conductivity, 
and a, b designating characteristic curves thereof. 
In addition, the H-content of the above described respective a-SiC films 
was measured by the infrared absorption method with the results as shown 
in FIG. 4. 
Referring to FIG. 4, an axis of abscissa designates the value x in 
Si.sub.1-x C.sub.x an axis of ordinate designating the H-content, that is, 
a value of y in [Si.sub.1-x C.sub.x ].sub.1-y H.sub.y .smallcircle. marks 
designating a plot of a quantity of H joined to Si atoms, marks 
designating a plot of a quantity of H joined to C atoms, and c, d 
designating characteristic curves thereof. 
It is clearly found from FIG. 4 that the values of y of the a-SiC films 
according to the present EXAMPLE are all within a range of 0.3 to 0.4. 
In addition, it is clear from FIG. 3 that if the C-content x is within a 
range of 0 to 0.5, a ratio of the photoconductivity to the dark 
conductivity is remarkably increased, whereby the superior 
photosensitivity is obtained. 
EXAMPLE 2 
Next, in the present EXAMPLE the a-SiC film (having a film-thickness of 
about 1 micron) was formed by the glow-discharge with setting the flow 
rate of the SiH.sub.4 gas at 200 sccm, the flow rate of the C.sub.2 
H.sub.2 gas at 20 sccm, the flow rate of the H.sub.2 gas at 0 to 1,000 
sccm, the high-frequency electric power at 50 to 300 W and the gas 
pressure at 0.3 to 1.2 Torr. 
Thus, various kinds of a-SiC film, of which C-content x was set at 0.3 and 
H-content y was varied, were formed and their photoconductivity and dark 
conductivity were measured with the results as shown in FIG. 5. 
Referring to FIG. 5, an axis of abscissa designates the H-content, that is, 
the value y in [Si.sub.0.7 C.sub.0.3 ].sub.1-y H.sub.y an axis of ordinate 
designating the conductivity, .smallcircle. marks designating a plot of 
the photoconductivity for the exposure wavelength of 550 nm (luminous 
quantity: 50 microW/cm.sup.2), marks designating a plot of the dark 
conductivity, and e, f designating characteristic curves thereof. 
It is clear from FIG. 5 that if the value of y exceeds 0.2, the 
photoconductivity is increased and the dark conductivity is reduced. 
EXAMPLE 3 
In the present EXAMPLE the B element-containing a-SiC film (having a 
film-thickness of about 1 micron) was formed by the glow-discharge with 
setting the flow rate of the SiH.sub.4 gas at 200 sccm, the flow rate of 
the C.sub.2 H.sub.2 gas at 20 sccm, the flow rate of the B.sub.2 H.sub.6 
gas diluted with H.sub.2 (having a concentration of 0.2% or 40 ppm) at 5 
to 500 sccm, the flow rate of the H.sub.2 gas at 200 sccm, the 
high-frequency electric power at 150 W, and the gas pressure at 0.6 Torr. 
Thus, various kinds of a-SiC film, of which C-content x was set at 0.2 and 
B element-content was varied, were formed and their photoconductivity and 
dark conductivity were measured with the results as shown in FIG. 6. 
In the present EXAMPLE the PH.sub.3 gas was used in place of the above 
described B.sub.2 H.sub.6 gas to form various kinds of a-SiC film, of 
which P element-content was varied, also and their photoconductivity and 
dark conductivity were measured. 
Referring to FIG. 6, an axis of abscissa designates the B element-content 
(or the P element-content), an axis of ordinate designating the 
conductivity, .smallcircle. marks designating a plot of the 
photoconductivities for the exposure wavelength of 550 nm (luminous 
quantity: 50 microW/cm.sup.2), marks designating a plot of the dark 
conductivities, and g, h designating characteristic curves thereof. 
It is clear from FIG. 6 that if the B element is contained at 1 to 1,000 
ppm, the ratio of the photoconductivity to the dark conductivity is 
remarkably increased, and, if the B element is contained in a quantity 
exceeding 1,000 ppm, the dark conductivity is increased. 
In addition, as for the P element, the photoconductivity and dark 
conductivity were still more remarkably increased. 
In addition, the C-content x and the H-content y of every a-SiC film 
according to the present EXAMPLE is 0.30 and 0.35, respectively. 
Thus, it could be confirmed that the valence electron of the above 
described a-SiC films was controlled by the B element and the P element, 
whereby the superior film quality for semiconductor was obtained. 
EXAMPLE 4 
In the present EXAMPLE various kinds of a-SiC photoconductive layer (Sample 
Nos. A-1 to A-8) were formed under the comparatively reduced film-forming 
speed condition shown in Table 1. And, their C-content, that is, the value 
of x, was measured with the results as shown in Table 1. 
The sample Nos. marked with * are outside of the scope of the present 
invention. 
TABLE 1 
__________________________________________________________________________ 
Raw mate- Diluent Elec- Film- 
rial gas gas tric Temper- 
thick- 
Carbon- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
Pressure 
power 
Time 
ature 
ness 
content 
Sample No 
sccm 
sccm 
sccm Torr W minute 
.degree.C. 
.mu.m 
X 
__________________________________________________________________________ 
A-1 20 1 700 1.2 100 30 250 1.0 0.1 
A-2 20 2 700 1.2 100 30 250 1.0 0.2 
A-3 20 4 700 1.2 100 30 250 1.0 0.3 
A-4 20 8 700 1.2 100 30 250 1.0 0.4 
A-5 20 12 700 1.2 100 30 250 1.0 0.55 
A-6 20 16 700 1.2 100 30 250 1.0 0.6 
A-7 20 20 700 1.2 100 30 250 1.0 0.65 
A-8 20 25 700 1.2 100 30 250 1.0 0.7 
__________________________________________________________________________ 
The spectral sensitivity characteristics of the sample Nos. A-1, A-2, A-3 
and A-7 shown in Table 1 were measured with the results as shown in FIG. 
30. These measurements were carried out under the condition that the 
luminous quantity was 50 microW/cm.sup.2 for each wavelength. In addition, 
the H-content (the value of y) was measured for the respective samples 
with the results that the H-content of the samples A-1, A-2, A-3 and A-7 
was within a range of 0.2 to 0.4. 
Referring to FIG. 30, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the conductivity, and .smallcircle. marks, .DELTA. 
marks, .gradient. marks and x marks designating a plot of the measured 
values for the sample No. A-1, A-2, A-3 and A-7, respectively. 
It is clear from FIG. 30 that the sample Nos. A-1, A-2 and A-3 according to 
the present invention have a high photoconductivity, in particular the 
sample No. A-1 has the highest photoconductivity. 
EXAMPLE 5 
In the present EXAMPLE various kinds of a-SiC photoconductive layer (Sample 
Nos. B-1 to B-5) were formed under the comparatively higher film-forming 
speed condition. And, the C-content, that is, the value of x, in each 
a-SiC photoconductive layer was measured with the results as shown in 
Table 2. 
The sample Nos. marked with * are outside of the scope of the present 
invention. 
TABLE 2 
__________________________________________________________________________ 
Raw mate- Diluent Elec- Film- 
rial gas gas tric Temper- 
thick- 
Carbon- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
Pressure 
power 
Time 
ature 
ness 
content 
Sample No 
sccm 
sccm 
sccm Torr W minute 
.degree.C. 
.mu.m 
X 
__________________________________________________________________________ 
B-1 200 
10 300 1.2 100 6 250 1.0 0.15 
B-2 200 
20 300 1.2 100 6 250 1.0 0.25 
B-3 200 
40 300 1.2 100 6 250 1.0 0.35 
B-4 200 
80 300 1.2 100 6 250 1.0 0.55 
B-5 200 
120 
300 1.2 100 6 250 1.0 0.65 
__________________________________________________________________________ 
As for the sample Nos. B-1, B-2, B-3 and B-5 shown in Table 2, the spectral 
sensitivity characteristics were measured with the results as shown in 
FIG. 31. In addition, the H-content (the value of y) of the respective 
samples was measured with the results that the H-content of the sample 
Nos. B-1, B-2, B-3 and B-5 is within a range of 0.2 to 0.4. 
Referring to FIG. 31, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the conductivity, and .largecircle. marks, .DELTA. 
marks, .gradient. marks and x marks designating a plot of measured values 
for the sample No. B-1, B-2, B-3 and B-5, respectively. 
It is clear from FIG. 31 that the sample Nos. B-1, B-2 and B-3 according to 
the present invention have the high photoconductivity, in particular the 
sample No. B-1 has the highest photoconductivity. 
EXAMPLE 6 
Next, the present inventors produced various kinds of a-SiC photoconductive 
layer (Sample Nos. C-1 to C-5) by the use of the CH.sub.4 gas in place of 
the C.sub.2 H.sub.2 gas under the film-forming conditions shown in Table 
3. And, the C-content (the value of x) and the H-content (the value of y) 
of the respective samples were measured with the results as shown in Table 
3. 
TABLE 3 
__________________________________________________________________________ 
Raw mate- Diluent Elec- Film- 
rial gas gas tric Temper- 
thick- 
Carbon- 
Hydrogen- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
Pressure 
power 
Time 
ature 
ness 
content 
content 
Sample No 
sccm 
sccm 
sccm Torr W minute 
.degree.C. 
.mu.m 
x y 
__________________________________________________________________________ 
C-1 10 10 300 1.2 100 60 250 1.0 0.05 0.15 
C-2 10 20 300 1.2 100 60 250 1.0 0.1 0.13 
C-3 10 40 300 1.2 100 60 250 1.0 0.15 0.12 
C-4 10 80 300 1.2 100 60 250 1.0 0.3 0.10 
C-5 10 120 
300 1.2 100 60 250 1.0 0.5 0.10 
__________________________________________________________________________ 
The spectral sensitivity characteristics of the sample Nos. C-1, C-2 and 
C-3 shown in Table 3 were measured with the results as shown in FIG. 32. 
Referring to FIG. 32, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the photoconductivity, and .smallcircle. marks, 
.DELTA. marks and .gradient. marks designating a plot of measured values 
for the sample Nos. C-1, C-2 and C-3. 
It is clear from FIG. 32 that the a-SiC film having the value of y less 
than 0.2 has not the sufficient photoconductive characteristics even 
though the value of x is within the preferable range. 
Preferred Embodiment of the First Invention 
EXAMPLE 7 
Next, the present inventors formed two kinds of a-SiC photoconductive layer 
on an electrically conductive aluminum substrate in a manner shown in 
Table 4 and piled up the organic photosemiconductive layer (having a 
thickness of 15 microns) on said respective layers by the coating method 
in the following manner. 
Method of Coating the Organic Photosemiconductive Layer 
2, 4, 7-trinitrofluorenon (hereinafter called TNF for short) was dissolved 
in 1,4-dioxane as a solvent and additionally a polyester resin 
[LEXAN-LS2-11] was added followed by being subjected to the ultrasonic 
dispersion for 40 minutes. And, the resulting dispersion was coated on 
both a-SiC photoconductive layers by means of a bar coater and then dried 
at 80.degree. C. by a hot wind. 
Thus, two kinds of positive charge type electrophotographic sensitive 
member according to the present invention (the sensitive members A, B) 
were produced. 
TABLE 4 
__________________________________________________________________________ 
Raw mate- Diluent 
rial gas gas Electric Film- 
Sensitive 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
Pressure 
power 
Time 
Temperature 
thickness 
member 
sccm 
sccm 
sccm Torr W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
A 20 1 700 1.2 100 30 250 1.0 
B 200 
10 300 0.8 100 8 250 1.0 
__________________________________________________________________________ 
The dark- and photoattenuation characteristics of the sensitive member A 
were measured with the results as shown in FIG. 33. In addition, the 
spectral sensitivity characteristics of the sensitive member A were 
measured with the results as shown in FIG. 34. 
Referring to FIG. 33, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating the charge acceptance (volt), i 
designating a dark attenuation curve, and i-1, i-2 and i-3 designating a 
photoattenuation curve at the exposure wavelength of 400 nm, 450 nm and 
550 nm, respectively. 
As to the measuring conditions, the electrification was carried out by the 
use of the corona charger with a voltage of +6 kV applied and the exposure 
was carried out with setting the luminous quantity for the respective 
wavelengths at 0.15 microw/cm.sup.2. And, the change of charge acceptance 
was measured by the use of the surface potentiometer provided with a 
phototransmission type measuring probe. 
In addition, the measurements of the positive charge sensitive member, 
which will be mentioned later, were carried out in the same manner as the 
above described. The measurements of the negative charge sensitive member 
were carried out with applying a voltage of -6 kV. 
It is clear from FIG. 33 that the electrophotographic sensitive members 
have the sufficient charge characteristics and dark attenuation 
characteristics and the superior photoattenuation characteristics. 
In addition, referring to FIG. 34, an axis of abscissa designates a 
wavelength, an axis of ordinate designating the photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member A. In addition, for comparison, the organic 
photosemiconductive layer was formed on the sample No. C-1 as the a-SiC 
photoconductive layer by the same method as in the present EXAMPLE to 
produce the electrophotographic sensitive member. A plot of measured 
values for this sensitive member is shown by .increment. marks. 
It is clear from FIG. 34 that the sensitive member A is remarkably superior 
in photosensitivity. 
In addition, the present inventors measured the dark- and photoattenuation 
characteristics of also the sensitive member B with the superior 
characteristics similarly to the sensitive member A. 
Preferred Embodiment of the Fourth Invention 
EXAMPLE 8 
In the present EXAMPLE various kinds of a-SiC photoconductive layer (Sample 
Nos. D-1 to D-5) were formed under the lower film-forming speed conditions 
shown in Table 5. And, the C-content, that is, the value of x,0and the B 
element-content of said respective a-SiC photoconductive layer were 
measured with the results as shown in Table 5. 
The sample Nos. marked with * are outside of the scope of the present 
invention. 
Flow rate marked with ** is a flow rate of the B.sub.2 H.sub.6 gas diluted 
with the H.sub.2 gas at a concentration of 400 ppm. 
TABLE 5 
__________________________________________________________________________ 
Raw mate- Diluent 
Impurity Elec- Film- 
rial gas gas gas tric Temper- 
thick- 
Carbon- 
.beta.-element- 
Sample 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
Pressure 
power 
Time 
ature 
ness 
content 
content 
No sccm 
sccm 
sccm sccm Torr W minute 
.degree.C. 
.mu.m 
x ppm 
__________________________________________________________________________ 
D-1 20 1 700 0.2 1.2 100 30 250 1.0 0.1 2 
D-2 20 1 700 2 1.2 100 30 250 1.0 0.1 20 
D-3 20 1 700 20 1.2 100 30 250 1.0 0.1 200 
D-4 20 1 700 40 1.2 100 30 250 1.0 0.1 500 
D-5 20 1 700 100 1.2 100 30 250 1.0 0.1 1500 
__________________________________________________________________________ 
The spectral characteristics of the sample Nos. D-1, D-2, D-4 and D-5 shown 
in Table 5 were measured with the results as shown in FIG. 35. In 
addition, the H-content (the value of y) of the respective samples was 
measured with the results that it was within a range of 0.2 to 0.4 in 
every case. 
Referring to FIG. 35, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the conductivity, and .smallcircle. marks, 
.increment. marks, .gradient. marks and x marks designating a plot of 
measured values for the sample No. D-1, D-2, D-4 and D-5, respectively. 
It is clear from FIG. 35 that the Sample Nos. D-1, D-2 and D-4 according to 
the present invention have the enhanced photoconductivity. 
EXAMPLE 9 
In the present EXAMPLE various kinds of a-SiC photoconductive layer (Sample 
Nos. E-1 to E-5) were formed under the higher film-forming speed 
conditions shown in Table 6. And, the C-content (the value of x) and the B 
element-content of the respective a-SiC photoconductive layers were 
measured with the results as shown in Table 6. 
The sample Nos. marked with * are outside of the scope of the present 
invention. 
Flow rate marked with ** is a flow rate of the B.sub.2 H.sub.6 gas diluted 
with the H.sub.2 gas at a concentration of 0.4%. 
TABLE 6 
__________________________________________________________________________ 
Raw mate- Diluent 
Impurity Elec- Film- 
rial gas gas gas tric Temper- 
thick- 
Carbon- 
.beta.-element- 
Sample 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
Pressure 
power 
Time 
ature 
ness 
content 
content 
No sccm 
sccm 
sccm sccm Torr W minute 
.degree.C. 
.mu.m 
x ppm 
__________________________________________________________________________ 
E-1 200 
20 300 0.2 1.2 100 6 250 1.0 0.25 2 
E-2 200 
20 300 2 1.2 100 6 250 1.0 0.25 20 
E-3 200 
20 300 20 1.2 100 6 250 1.0 0.25 200 
E-4 200 
20 300 40 1.2 100 6 250 1.0 0.25 500 
E-5 200 
20 300 100 1.2 100 6 250 1.0 0.25 1500 
__________________________________________________________________________ 
The spectral sensitivity characteristics of the Sample Nos. E-1, E-2, E-4 
and E-5 shown in Table 6 were measured with the results as shown in FIG. 
36. In addition, the H-content (the value of v) of the respective samples 
was measured with the results that it was within a range of 0.2 to 0.4. 
Referring to FIG. 36, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the conductivity, and .smallcircle. marks, .DELTA. 
marks, .gradient. marks and x marks designating a plot of measured values 
for the Sample Nos. E-1, E-2, E-4 and E-5, respectively. 
It is clear from FIG. 36 that the samples according to the present 
invention have the enhanced photoconductivity. 
EXAMPLE 10 
Next, the present inventors produced various kinds of a-SiC photoconductive 
layer (Sample Nos. F-1 to F-5) by the use of the CH.sub.4 gas in place of 
the C.sub.2 H.sub.2 gas under the film-forming conditions shown in Table 
7. And, the C-content (the value of x), the H-content (the value of y) and 
the B element-content of the respective samples were measured with the 
results as shown in Table 7. 
Flow rate marked with * is a flow rate of the B.sub.2 H.sub.6 gas diluted 
with the H.sub.2 gas at a concentration of 100 ppm. 
TABLE 7 
__________________________________________________________________________ 
Raw mate- Diluent 
Impurity 
rial gas gas gas Electric Film- 
Carbon- 
Hydrogen- 
.beta.-element- 
Sample 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
Pressure 
power 
Time 
Temperature 
thickness 
content 
content 
content 
No sccm 
sccm 
sccm sccm Torr W minute 
.degree.C. 
.mu.m 
x y ppm 
__________________________________________________________________________ 
F-1 10 10 300 5 1.2 100 60 250 1.0 0.05 0.15 20 
F-2 10 20 300 10 1.2 100 60 250 1.0 0.1 0.13 20 
F-3 10 40 300 20 1.2 100 60 250 1.0 0.15 0.12 20 
F-4 10 80 300 40 1.2 100 60 250 1.0 0.3 0.10 20 
F-5 10 120 
300 60 1.2 100 60 250 1.0 0.5 0.10 20 
__________________________________________________________________________ 
The spectral sensitive characteristics of the Sample Nos. F-1, F-2 and F-3 
shown in Table 7 were measured with the results as shown in FIG. 37. 
Referring to FIG. 37, an axis of abscissa designates a wavelength, an axis 
of ordinate designating the conductivity, and .smallcircle. marks, .DELTA. 
marks, .gradient. marks and x marks designating a plot of measured values 
for the Sample No. F-1, F-2 and F-3, respectively. 
It is clear from FIG. 37 that every sample can not have the enhanced 
conductivity. 
EXAMPLE 11 
Next, the present inventors formed two kinds of a-SiC photoconductive layer 
on the electrically conductive Al substrate, as shown in Table 8, and the 
organic photosemiconductive layer (having a thickness of 15 microns) was 
piled up on said respective layers as follows: 
Method of Coating the Organic Photosemiconductive Layer 
Hydrazone was dissolved in 1,4-dioxane as a solvent and a polyester resin 
[Lexan-LS2-11] was added in the same quantity as hydrazone followed by the 
ultrasonic dispersion for 40 minutes. And, the resulting dispersion was 
coated on both a-SiC photoconductive layers by the use of a bar coater and 
then subjected to the hot wind drying. 
Thus, two kinds of negative charge type electrophotographic sensitive 
member according to the fourth invention were produced (the sensitive 
members C, D). 
Flow rate marked with * is a flow rate of the B.sub.2 H.sub.6 gas diluted 
with the H.sub.2 gas at a concentration of 100 ppm. 
TABLE 8 
__________________________________________________________________________ 
Raw mate- Diluent 
Impurity Elec- Film- 
rial gas gas tric Temper- 
thick- 
Sensitive 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
Pressure 
power 
Time 
ature 
ness 
member 
sccm 
sccm 
sccm sccm Torr W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
C 20 
1 700 10 1.2 100 30 250 1.0 
D 200 
20 300 100 0.8 100 8 250 1.0 
__________________________________________________________________________ 
The dark- and photosensitive attenuation characteristics of the sensitive 
member C were measured with the results as shown in FIG. 38. In addition, 
the spectral sensitivity characteristics were measured with the results as 
shown in FIG. 39. 
Referring to FIG. 38, an axis of abscissa designates an attenuation time 
(second), an axis of ordinate designates a surface potential (volt), j 
designating dark attenuation curves, and j-1, j-2 and j-3 designating a 
photoattenuation curve in the case where the exposure wavelength is 400 
nm, 450 nm and 550 nm, respectively. 
It is clear from FIG. 38 that the charge acceptance was slightly reduced in 
comparison with that of the sensitive member A but the photoattenuation 
curve shows superior characteristics and the photosensitivity was 
improved. 
In addition, referring to FIG. 39, an axis of abscissa designates a 
wavelength, an axis of ordinate designating the photoconductivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member C. Furthermore, for comparison, the organic 
photosemiconductive layer was formed on the sample No. F-1 as the a-SiC 
photosemiconductive layer to produce the electrophotographic sensitive 
member. A plot of measured value of this sensitive member is shown by 
.DELTA. marks. 
It is clear from FIG. 39 that the sensitive member C is remarkably superior 
in photosensitivity. 
In addition, the present inventors measured the dark-and photoattenuation 
characteristics as well as the spectral sensitivity characteristics of 
also the sensitive member D with the results that every sensitive member D 
has superior characteristics similarly to the sensitive member C. 
Preferred Embodiment of the Second Invention 
EXAMPLE 12 
An Al flat plate (25 mm.times.50 mm) with a surface polished was disposed 
in an interior of the reaction tube of the glow-discharge decomposition 
apparatus and the first layer zone (2a) and the second layer zone (2b) 
were formed on said flat plate in turn under the high-speed film-forming 
conditions shogun in Table 9. Subsequently, a disk-like Al electrode (3 mm 
o) was formed by the vacuum vapor deposition method to produce the 
photoconductive member as shown in FIG. 40. In addition, referring to FIG. 
40, reference numeral (29) and (30) designates the flat plate and the Al 
electrode, respectively. 
B.sub.2 H.sub.6 gas marked with *, is diluted with the H.sub.2 gas at a 
concentration of 0.2%. 
TABLE 9 
__________________________________________________________________________ 
Flow rate of gas 
Gas High-frequency 
Substrate 
Thick- 
introduced (sccm) 
pressure 
electric power 
temperature 
ness 
Kind of layer 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
(Torr) 
(W) (.degree.C.) 
(.mu.m) 
__________________________________________________________________________ 
Second layer 
200 
20 270 
-- 0.60 150 250 1.0 
zone 
First layer 
80 
10 350 
120 0.45 80 250 1.0 
zone 
__________________________________________________________________________ 
The C-content and the B element-content of thus formed first layer zone 
(2a) and second layer zone (2b) were measured with the results as shown in 
Table 10. 
TABLE 10 
______________________________________ 
B element- 
Value of x 
content 
Kind of layer in Si.sub.1-x C.sub.x 
(ppm) 
______________________________________ 
Second layer 0.17 -- 
zone 
First layer 0.23 3000 
zone 
______________________________________ 
The voltage-electric current characteristics of thus obtained a-SiC 
photoconductive member were measured with applying a voltage to the side 
of Al electrode (30) and connecting the flat plate (29) to the earth side, 
as shown in FIG. 40, with the results as shown in FIG. 41. 
In addition, in the present EXAMPLE the the B.sub.2 H.sub.6 gas was not 
introduced and other film-forming conditions were set quite identically 
with those in the present EXAMPLE in the formation of the first layer 
zone, whereby the a-SiC photoconductive member having the first layer zone 
containing no B element was produced, and this was used as COMATIVE 
EXAMPLE of which voltage-electric current characteristics were also 
measured. 
Referring to FIG. 41, an axis of abscissa designates a voltage applied to 
the Al electrode (30), an axis of ordinate designating a value of electric 
current, .smallcircle. marks designating a plot of measured values for the 
a-SiC photoconductive member according to the present invention, and 
marks designating a plot of measured values for the a-SiC photoconductive 
member according to COMATIVE EXAMPLE. 
It is clear from FIG. 41 that with the a-SiC photoconductive member 
according to the present invention, even though the positive voltage is 
applied to the Al electrode (30), an electric current is hardly flown, 
but, if the negative voltage is applied to the electrode (30), a 
remarkably large electric current is flown. 
EXAMPLE 13 
The same a-SiC photoconductive layer as in EXAMPLE 12 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) mainly comprising TNF similarly to 
EXAMPLE 7 was formed to obtain the positive charge type 
electrophotographic sensitive member. 
The characteristics of thus obtained electrophotographic sensitive member 
were measured by means of the electrophotographic characteristic-measuring 
apparatus with the results that not only the superior photosensitivity and 
charge acceptance but also the reduced residual voltage were obtained. 
EXAMPLE 14 
In the production of the above described electrophotographic sensitive 
member according to EXAMPLE 13 the a-SiC photoconductive layer according 
to EXAMPLE 12 (COMATIVE EXAMPLE) was formed and then the same organic 
photosemiconductive layer was formed to produce the electrophotographic 
sensitive member. 
The photosensitivity of thus obtained electrophotographic sensitive member 
was measured with the results that the photosensitivity was reduced by 
about 10% and the residual potential is slightly increased in comparison 
with the electrophotographic sensitive member according to EXAMPLE 13. 
EXAMPLE 15 
In addition, the present inventors varied the flow rate of the B.sub.2 
H.sub.6 gas in the production of the electrophotographic sensitive member 
according to EXAMPLE 13 to produce 11 kinds of electrophotographic 
sensitive member (sensitive members E-1 to E-11) of which B 
element-content of the first layer zone was varied, as shown in Table 11. 
The photosensitivity, surface potential and residual potential of these 
electrophotographic sensitive members were measured with the results as 
shown in Table 11. 
Referring to Table 11, the photosensitivity is divided into three ranks 
expressed by .circleincircle. marks, .smallcircle. marks and .DELTA. marks 
by the relative evaluation. .circleincircle. marks show the most superior 
photosensitivity, .smallcircle. marks showing the somewhat superior 
photosensitivity, and .DELTA. marks showing the photosensitivity slightly 
inferior to other cases. 
Also the evaluation of the charge acceptance is divided into three ranks 
expressed by .circleincircle. marks, .smallcircle. marks and .DELTA. 
marks. .circleincircle. marks show the least charge acceptance, 
.smallcircle. marks showing the somewhat higher charge acceptance and 
.DELTA. marks showing the charge acceptance lower than other cases. 
Furthermore, also the evaluation of the residual potential is divided into 
three ranks by the relative evaluation. .circleincircle. marks shown the 
least residual potential, .smallcircle. marks showing the somewhat reduced 
residual potential, and .DELTA. marks showing the residual potential 
higher than that in other cases. 
The above described evaluation method is same also in EXAMPLES which will 
be mentioned later. 
Sensitive members marked with * are outside of the scope of the present 
invention. 
TABLE 11 
______________________________________ 
B element-content 
Photo- Charge 
Sensitive 
of the first layer 
sensi- accept- Residual 
member zone (ppm) tivity ance potential 
______________________________________ 
E-1 0.1 .DELTA. .DELTA. .largecircle. 
E-2 3 .largecircle. 
.DELTA. .largecircle. 
E-3 50 .largecircle. 
.DELTA. .largecircle. 
E-4 200 .largecircle. 
.largecircle. 
.largecircle. 
E-5 400 .largecircle. 
.largecircle. 
.largecircle. 
E-6 700 .circleincircle. 
.circleincircle. 
.circleincircle. 
E-7 1500 .circleincircle. 
.circleincircle. 
.circleincircle. 
E-8 3500 .circleincircle. 
.circleincircle. 
.circleincircle. 
E-9 6000 .circleincircle. 
.largecircle. 
.largecircle. 
E-10 8000 .largecircle. 
.circleincircle. 
.circleincircle. 
E-11 13000 .DELTA. .DELTA. .DELTA. 
______________________________________ 
It is clear from Table 11 that the sensitive members E-2 to E-10 show the 
superior photosensitivity and the reduced residual potential. Above all, 
the sensitive members E-4 to E-10 showed the higher charge acceptance. 
However, the sensitive member E-1 is inferior in photosensitivity and 
charge acceptance and the sensitive member E-11 is not improved in 
photosensitivity, charge acceptance and residual potential. 
EXAMPLE 16 
The first layer zone (2a) and the second layer zone (2b) were formed on the 
Al substrate (29) turn under the lower film-forming speed conditions shown 
in Table 12 in the same manner as in EXAMPLE 12 and then the Al electrode 
(30) was formed. The voltage-electric current characteristics of thus 
obtained photoconductive member were measured with the results as shown in 
FIG. 42. 
B.sub.2 H.sub.6 gas marked with * is diluted with the H.sub.2 gas at a 
concentration of 0.2%. 
TABLE 12 
__________________________________________________________________________ 
High-fre- 
Flow rate of gas 
Gas quency 
Substrate 
introduced pres- 
electric 
temper- 
Thick- B element- 
Kind of 
(sccm) sure 
power 
ature 
ness 
Value of x 
content 
layer SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
(Torr) 
(W) (.degree.C.) 
(.mu.m) 
in Si.sub.1-x C.sub.x 
(ppm) 
__________________________________________________________________________ 
Second layer 
20 1 700 
-- 1.20 
100 250 0.1 0.1 -- 
zone 
First layer 
20 2 700 
45 1.20 
100 250 1.0 0.2 3000 
zone 
__________________________________________________________________________ 
The voltage-electric current characteristics of thus obtained a-SiC 
photoconductive member were measured with applying a voltage to the side 
of the Al electrode (30) and connecting the flat plate (29) to the earth 
side with the results as shown in FIG. 42. 
In addition, in the present EXAMPLE the B.sub.2 H.sub.6 gas was not 
introduced and other film-forming conditions were set in the quite same 
manner as in the present EXAMPLE to produce the a-SiC photoconductive 
member having the first layer zone containing no B element. This was used 
as COMATIVE EXAMPLE of which voltage-electric current characteristics 
were also measured. 
Referring to FIG. 42, an axis of abscissa designates the voltage applied to 
the Al electrode (30), an axis of ordinate designating the value of 
electric current, .smallcircle. marks designating a plot of measured 
values for the a-SiC photoconductive member according to the present 
invention, and marks designating a plot of measured values for the a-SiC 
photoconductive member according to COMATIVE EXAMPLE. 
It is clear from FIG. 42 that with the a-SiC photoconductive member 
according to the present invention, even though the positive voltage is 
applied to the Al electrode (30), an electric current is hardly flown, 
but, in the case where the negative voltage is applied to the electrode 
(30), a remarkably large electric current is flown. 
EXAMPLE 17 
The same a-SiC photoconductive layer as in EXAMPLE 16 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) mainly comprising TNF in the same 
manner as in EXAMPLE 7 to obtain the positive charge type 
electrophotographic sensitive member. 
The characteristics of thus obtained electrophotographic sensitive member 
were measured by means of the electrophotographic characteristic-measuring 
apparatus with the results that the superior photosensitivity and charge 
acceptance were obtained and the reduced residual potential was obtained. 
EXAMPLE 18 
Next, the present inventors formed two kinds of a-SiC photoconductive 
layer, as shown in Table 13, and then the organic photosemiconductive 
layer (having a thickness of about 15 microns) mainly comprising TNF in 
the same manner as in EXAMPLE 7 was formed on the respective a-SiC 
photoconductive layers to produce two kinds of positive charge type 
electrophotographic sensitive members. 
Flow rate marked with ** is a flow rate of the B.sub.2 H.sub.6 gas diluted 
with the H.sub.2 gas at a concentration of 0.2%. 
TABLE 13 
__________________________________________________________________________ 
Raw mate- Diluent 
Impurity Elec- Film- 
rial gas gas gas tric Temper- 
thick- 
Sensitive 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
Pressure 
power 
Time 
ature 
ness 
member 
sccm 
sccm 
sccm sccm Torr W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
F 20 
1 700 
30 1.2 100 30 250 1.0 
20 
1 700 
-- 1.2 100 15 250 0.5 
G 200 
20 300 
300 0.8 100 6 250 1.0 
200 
20 300 
-- 0.8 100 3 250 0.5 
__________________________________________________________________________ 
The dark- and photoattenuation characteristics of the sensitive member F 
were measured with the results as shown in FIG. 43 and the spectral 
sensitivity characteristics were measured with the results as shown in 
FIG. 44. 
Referring to FIG. 43, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating the surface potential (volt), k 
designating a dark attenuation curve, and k-2 and k-3 designating a 
photoattenuation curve at the exposure wavelength of 400 nm, 450 nm and 
550 nm, respectively. 
It is clear from FIG. 43 that the electrifying capacity is improved in 
comparison with that in the first invention. 
In addition, referring to FIG. 44, an axis of abscissa designates a 
wavelength, an axis of ordinate designating a photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member F. In addition, the B.sub.2 H.sub.6 gas (having a 
concentration of 0.2%) was added to the Sample No. C-1 at a flow rate of 
30 sccm and a thickness of 1.0 micron was given in the formation of the 
first layer zone and a thickness of 0.5 microns was given under the same 
film-forming conditions as for the Sample No. C-1 in the formation of the 
second layer zone to form the a-SiC photoconductive layer as COMATIVE 
EXAMPLE. Then the organic photosemiconductive layer was formed on the 
a-SiC photoconductive layer in the same manner as in the present EXAMPLE 
to produce the positive charge type electrophotographic sensitive member. 
A plot of measured values for this sensitive member is shown by .DELTA. 
marks. 
It is clear from FIG. 44 that the sensitive member F shows the remarkably 
higher photosensitivity in comparison with that in COMATIVE EXAMPLE 
which is improved in comparison with also that in the first invention. 
In addition, the present inventors measured the dark- and photoattenuation 
characteristics as well as the spectral sensitivity characteristics of the 
sensitive member G in the same manner as in the present EXAMPLE with the 
same effect as for the sensitive member F in every case. 
Preferred Embodiments of the Third Invention 
EXAMPLE 19 
The Al flat plate (25 mm.times.50 mm), of which surface had been ground, 
was placed within the reaction tube of the glow-discharge decomposition 
apparatus and the first layer zone (2a) and the second layer zone (2b) 
were formed on said flat plate in turn under the film-forming conditions 
shown in Table 14. Subsequently, the disk-like Al electrode (having a 
diameter of 3 mm) was formed by the vacuum vapor deposition method to 
produce photoconductive members as shown in FIG. 40. 
B.sub.2 H.sub.6 gas marked with * is diluted with the H.sub.2 gas at a 
concentration of 0.2%. 
The PH.sub.3 gas marked with ** is diluted with the H.sub.2 gas at a 
concentration of 17 ppm. 
TABLE 14 
__________________________________________________________________________ 
High-fre- 
Raw mate- 
Diluent 
Impurity quency Film- 
rial gas 
gas gas Pres- 
electric Temper- 
thick- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
PH.sub.3 
sure 
power 
Time 
ature 
ness 
Sample No 
Kind of layer 
sccm 
sccm 
sccm sccm 
sccm Torr 
W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
G-1 First layer 
20 
1 700 30 1.2 
100 30 250 1.0 
(Lower speed 
zone 
film-forma- 
Second layer 
20 
1 700 15 1.2 
100 15 250 0.5 
tion) zone 
G-2 First layer 
200 
20 300 300 0.8 
100 6 250 1.0 
(Higher speed 
zone 
film-forma- 
Second layer 
200 
20 300 150 0.8 
100 3 250 0.5 
tion) 
__________________________________________________________________________ 
The C-content, the B element-content and the element-content of the first 
layer zone (2a) and the second layer zone (2b) were measured for the 
respective samples, on which the films had been formed in the above 
described manner, with the results as shown in Table 15. 
Table 15 
TABLE 15 
______________________________________ 
B element- 
P element- 
Value of x 
content content 
Sample No 
Kind of layer 
in Si.sub.1-x C.sub.x 
(ppm) (ppm) 
______________________________________ 
G-1 Second layer 
0.1 -- 10 
zone 
First layer 
0.1 2000 -- 
zone 
G-2 Second layer 
0.25 -- 10 
zone 
First layer 
0.25 2000 -- 
zone 
______________________________________ 
The voltage-electric current characteristics of thus obtained respective 
photoconductive members were measured with applying a voltage to the side 
of the Al electrode (30) and connecting the flat plate (29) to an earth 
side with the results as shown in FIGS. 45 and 46. 
FIG. 45 shows the voltage-electric current characteristics for the Sample 
No. G-1 and FIG. 46 shows the voltage-electric current characteristics for 
the Sample No. G-2. Referring to FIGS. 45 and 46, an axis of abscissa 
designates a voltage applied to the Al electrode (30), an axis of ordinate 
designating an electric current, and .smallcircle. marks designating a 
plot of measured values. 
In both FIG. 45 and FIG. 46 a plot of measured values for COMATIVE 
EXAMPLE is shown by .DELTA. marks. In every case, the B.sub.2 H.sub.6 gas 
(having a concentration of 0.2%) was mixed at a flow rate of 30 sccm under 
the film-forming conditions for the Sample No. C-1 and a thickness of 1.0 
micron was given in the formation of the first layer zone (2a) and the 
PH.sub.3 gas (having a concentration of 17 ppm) was mixed at a flow rate 
of 15 sccm and a thickness of 0.5 microns was given in the formation of 
the second layer zone (2b) to produce a-SiC photoconductive layers. 
It is clear from FIGS. 45 and 46 that with the a-SiC photoconductive 
members according to the present invention, even though the positive 
voltage is applied to the Al electrode (30), an electric current is hardly 
flown, but, in the case where the negative voltage is applied to the 
electrode (30), a remarkably large electric current is flown. 
In addition, comparing with the second invention, if the voltage applied is 
positive, the electric current is still more reduced, while, if the 
voltage applied is negative, the electric current is still more increased, 
that is, the a-SiC photoconductive members according to the third 
invention are superior to those according to the second invention in 
rectification property. 
EXAMPLE 20 
The same a-SiC photoconductive layer as in EXAMPLE 19 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) mainly comprising TNF in the same 
manner as in EXAMPLE 7 was formed to obtain a positive charge type 
electrophotographic sensitive member. 
Thus, the electrophotographic sensitive members it, I corresponding to the 
a-SiC photoconductive layers (G-1), (G-2) were produced. 
The dark- and photoattenuation characteristics of the sensitive member H 
were measured with the results as shown in FIG. 47. In addition, the 
spectral sensitivity characteristics were measured with the results as 
shown in FIG. 48. 
Referring to FIG. 47, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating a charge acceptance (volt), l 
designating a dark attenuation curve, and l-1, l-2 and l-3 designating a 
photoattenuation curve at the exposure wavelength of 400 nm, 450 nm and 
550 nm, respectively. 
It is clear from FIG. 47 that the electrifying capacity is improved in 
comparison with the first invention. 
In addition, referring to FIG. 48, an axis of abscissa designates a 
wavelength, an axis of ordinate designating the photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member H. In addition, for comparison, the organic 
photosemiconductive layer was similarly formed on the a-SiC 
photoconductive layer shown FIG. 45 to produce a positive charge type 
electrophotographic sensitive member. A plot of measured values for this 
sensitive member is shown by .DELTA. marks. 
It is clear from FIG. 48 that the photosensitivity of the sensitive member 
H is higher in comparison with that in the second invention. 
In addition, the dark- and photoattenuation characteristics as well as the 
spectral sensitivity characteristics of also the sensitive member I were 
measured by the present inventors with the same effect as in the sensitive 
member H in every case. 
EXAMPLE 21 
In addition, the present inventors varied the flow rate of the PH.sub.3 gas 
and the flow rate of B.sub.2 H.sub.6 gas in the production of the 
sensitive member I, whereby producing 15 kinds of electrophotographic 
sensitive member (sensitive members J-1 to J-15) with varied B 
element-content of the first layer zone and varied P element-content in 
the second layer zone, as shown in Table 16. 
The photosensitivity, charge acceptance and residual potential of these 
electrophotographic sensitive members were measured with the results as 
shown in Table 16. 
Sensitive members marked with * are outside of the scope of the present 
invention. 
TABLE 16 
______________________________________ 
B element- 
P element- 
content content 
of the first 
of the second 
Photo- 
Charge 
Sensitive 
layer zone 
layer zone sensi- 
accept- 
Residual 
member (ppm) (ppm) tivity 
ance potential 
______________________________________ 
J-1 0.1 15 .DELTA. 
.DELTA. 
.largecircle. 
J-2 5 30 .largecircle. 
.DELTA. 
.largecircle. 
J-3 70 30 .largecircle. 
.DELTA. 
.largecircle. 
J-4 300 2 .largecircle. 
.largecircle. 
.largecircle. 
J-5 1500 2 .largecircle. 
.largecircle. 
.largecircle. 
J-6 300 15 .circleincircle. 
.largecircle. 
.circleincircle. 
J-7 800 3 .circleincircle. 
.circleincircle. 
.circleincircle. 
J-8 2000 20 .circleincircle. 
.circleincircle. 
.circleincircle. 
J-9 3500 40 .circleincircle. 
.circleincircle. 
.circleincircle. 
J-10 7000 40 .largecircle. 
.circleincircle. 
.circleincircle. 
J-11 700 70 .circleincircle. 
.circleincircle. 
.circleincircle. 
J-12 7000 70 .largecircle. 
.largecircle. 
.largecircle. 
J-13 700 300 .largecircle. 
.largecircle. 
.largecircle. 
J-14 12000 40 .DELTA. 
.DELTA. 
.DELTA. 
J-15 700 700 .DELTA. 
.DELTA. 
.DELTA. 
______________________________________ 
It is clear from Table 16 that the sensitive members J-2 to J-13 show the 
superior photosensitivity, the enhanced charge ,acceptance and the reduced 
residual potential. 
It is, however, found that the sensitive member J-1 is inferior in 
photosensitivity and charge acceptance and the sensitive members J-14 and 
J-15 are not improved in photosensitivity, charge acceptance and residual 
potential. 
EXAMPLE 22 
An Al flat plate (25 mm.times.50 mm), of which surface had been ground, was 
placed within the reaction tube of the glow-discharge decomposition 
apparatus and the first layer zone (2a) and the second layer zone (2b) 
were formed on said flat plate in turn under the film-forming conditions 
shown in Table 17. Subsequently, a disk-like Al electrode (having a 
diameter of 3 mm) was formed by the vacuum vapor deposition method to 
produce a photoconductive member as shown in FIG. 40. 
B.sub.2 H.sub.6 gas marked with * is diluted with the H.sub.2 gas at a 
concentration of 0.2%. 
The PH.sub.3 gas marked with ** is diluted with the H.sub.2 gas at a 
concentration of 40 ppm. 
Numerical values marked with *** designate a flow rate of gases at the 
start of film-formation and the finish of film- formation and show the 
gradual decrease. 
TABLE 17 
__________________________________________________________________________ 
High-fre- 
Raw mate- 
Diluent 
Impurity quency Film- 
rial gas 
gas gas Pres- 
electric Temper- 
thick- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
PH.sub.3 
sure 
power 
Time 
ature 
ness 
Sample No 
Kind of layer 
sccm 
sccm 
sccm sccm sccm Torr 
W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
H-1 First layer 
20 
1 700 60 .fwdarw. 0 
1.2 
100 30 250 1.0 
(Lower speed 
zone 
film-forma- 
Second layer 
20 
1 700 15 1.2 
100 15 250 0.5 
tion) zone 
H-2 First layer 
200 
20 300 600 .fwdarw. 0 
0.8 
100 6 250 1.0 
(Higher speed 
zone 
film-forma- 
Second layer 
200 
20 300 150 0.8 
100 3 250 0.5 
tion) zone 
__________________________________________________________________________ 
The C-content, the maximum B element-content and the P element-content of 
the respective samples, on which the films had been formed in the above 
described manner, were measured with the results as shown in Table 18. 
TABLE 18 
______________________________________ 
Maximum 
Sample Value of x 
B element- 
P element- 
No Kind of layer 
in Si.sub.1-x C.sub.x 
content (ppm) 
content (ppm) 
______________________________________ 
H-1 Second layer 
0.1 -- 25 
zone 
First layer 
0.1 4000 -- 
zone 
H-2 Second layer 
0.25 -- 25 
zone 
First layer 
0.25 4000 -- 
zone 
______________________________________ 
The voltage-electric current characteristics of thus obtained respective 
a-SiC photoconductive members were measured with applying a voltage to the 
side of the Al electrode (30) and connecting the flat plate (29) to the 
earth side, as shown in FIG. 40 with the results as shogun in FIGS. 49 and 
50. 
FIG. 49 shows the voltage-electric current characteristics for the Sample 
No. H-1 and FIG. 50 shows the voltage-electric current characteristics for 
the Sample No. H-2. In addition, referring to FIGS. 49 and 50, an axis of 
abscissa designates a voltage applied to the Al electrode (30), an axis of 
ordinate designating an electric current, and .smallcircle. marks 
designating a plot of measured values. 
In both FIG. 49 and FIG. 50 a plot of measured values for COMATIVE 
EXAMPLE is shown by .DELTA. marks. In every case, the B.sub.2 H.sub.6 gas 
(having a concentration of 0.2%) was mixed with varying the flow rate 
thereof within a range of 60 to 0 sccm and a thickness of 1.0 micron was 
given under the film-forming conditions for the Sample No. C-1 in the 
formation of the first layer zone and the PH.sub.3 gas (having a 
concentration of 40 sccm) was mixed at a flow rate of 15 sccm and a 
thickness of 0.5 microns was given in the formation of the second layer 
zone to produce a-SiC photoconductive layers. 
As obvious from FIGS. 49 and 50, with the a-SiC photoconductive members 
according to the present invention, even though the positive voltage is 
applied to the Al electrode (30), an electric current is hardly flown, 
but, in the case where the negative voltage is applied to the electrode 
(30), a remarkably large electric current is flown. 
In addition, comparing with the second invention, if the voltage applied is 
positive, the electric current is still more reduced, while, if the 
voltage applied is negative, the electric current is still more increased, 
that is, the a-SiC photoconductive members according to the third 
invention are superior to those according to the second invention in 
rectification property. 
EXAMPLE 23 
The same a-SiC photoconductive layer as in EXAMPLE 22 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) mainly comprising TNF in the same 
manner as in EXAMPLE 7 to obtain a positive charge type 
electrophotographic sensitive member. 
Thus, the electrophotographic sensitive member K, L corresponding to the 
a-SiC photoconductive layer (H-1) and (H-2) were produced. 
The dark- and photoattenuation characteristics of the sensitive member K 
were measured with the results as shown in FIG. 51. In addition, the 
spectral sensitivity characteristics were measured with the results as 
shown in FIG. 52. 
Referring to FIG. 51, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating the charge acceptance (volt), m 
designating a dark attenuation curve, and m-1, m-2 and m-3 designating a 
photoattenuation curve at the exposure wavelength of 400 nm, 450 nm and 
550 nm, respectively. 
As obvious from FIG. 51, it can be confirmed that the electrifying capacity 
is improved in comparison with the first invention and the residual 
potential is reduced in comparison with FIG. 47 shown in EXAMPLE 20. 
In addition, referring to FIG. 52, an axis of abscissa designates a 
wavelength, an axis of ordinate designating the photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member K. For comparison, the organic photosemiconductive layer 
was similarly formed on the a-SiC photoconductive layer shown in FIG. 49 
to produce a positive charge rye electrophotographic sensitive member. A 
plot of measured values for this sensitive member is shown .DELTA. marks. 
As obvious from FIG. 52, the photosensitivity of the sensitive member K is 
higher in comparison with that in the second invention. 
In addition, the present inventors measured the dark- and photoattenuation 
characteristics as well as the spectral sensitivity characteristics for 
also the sensitive member L were measured with the same effect as the 
sensitive member K in every case. 
EXAMPLE 24 
In addition, the present inventors varied the maximum flow rate of the 
B.sub.2 H.sub.6 gas and the flow rate of the PH.sub.3 gas in the formation 
of the sensitive member L to produce 15 kinds of electrophotographic 
sensitive member (sensitive members M-1 to M-15) with varied maximum B 
element-content of the first layer zone and varied P element-content of 
the second layer zone, as shown in Table 19. 
The photosensitivity, the charge acceptance and the residual potential of 
these electrophotographic sensitive members were measured with the results 
as shown in Table 19. 
Sensitive members marked with * are outside of the scope of the present 
invention. 
TABLE 19 
______________________________________ 
Maximum 
B element- 
P element- 
content content 
of the first 
of the second 
Photo- 
Charge 
Sensitive 
layer zone 
layer zone sensi- 
accept- 
Residual 
member (ppm) (ppm) tivity 
ance potential 
______________________________________ 
M-1 0.3 10 .DELTA. 
.DELTA. 
.largecircle. 
M-2 5 20 .largecircle. 
.DELTA. 
.largecircle. 
M-3 70 10 .largecircle. 
.DELTA. 
.largecircle. 
M-4 400 3 .largecircle. 
.largecircle. 
.largecircle. 
M-5 2000 3 .largecircle. 
.largecircle. 
.largecircle. 
M-6 400 10 .circleincircle. 
.largecircle. 
.circleincircle. 
M-7 1000 8 .circleincircle. 
.circleincircle. 
.circleincircle. 
M-8 2000 20 .circleincircle. 
.circleincircle. 
.circleincircle. 
M-9 4000 35 .circleincircle. 
.circleincircle. 
.circleincircle. 
M-10 8000 35 .largecircle. 
.circleincircle. 
.circleincircle. 
M-11 4000 70 .largecircle. 
.largecircle. 
.largecircle. 
M-12 8000 70 .largecircle. 
.largecircle. 
.largecircle. 
M-13 50 300 .largecircle. 
.largecircle. 
.largecircle. 
M-14 12000 35 .DELTA. 
.DELTA. 
.DELTA. 
M-15 50 700 .DELTA. 
.DELTA. 
.DELTA. 
______________________________________ 
As obvious from Table 19, the sensitive members M-4 to M-13 showed the 
superior photosensitivity, the enhanced charge acceptance and the reduced 
residual potential and the sensitive members M-2 and M-3 were superior in 
photosensitivity and residual potential. 
It is, however, found that the sensitive member M-1 is inferior in 
photosensitivity and charge acceptance and the sensitive members M-14 and 
M-15 are not improved in charge acceptance and residual potential. 
Preferred Embodiments of the Fifth Invention 
EXAMPLE 25 
An Al flat plate (25 mm.times.50 mm), of which surface had been ground, was 
placed within the reaction tube of the glow-discharge decomposition 
apparatus and the first layer zone (2a) and the second layer zone (2b) 
were formed on said flat plate in turn under the film-forming conditions 
shown in Table 20. 
Subsequently, a disk-like Al electrode (having a diameter of 3 mm) was 
formed by the vacuum vapor deposition method to produce photoconductive 
members as shown in FIG. 40. 
The B.sub.2 H.sub.6 gas and the PH.sub.3 gas marked with * is diluted with 
the H.sub.2 gas at a concentration of 40 ppm, respectively. 
TABLE 20 
__________________________________________________________________________ 
High-fre- 
Raw mate- 
Diluent 
Impurity 
Gas 
quency 
rial gas 
gas gas pres- 
electric Temper- 
Thick- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
PH.sub.3 
sure 
power 
Time 
ative 
ness 
Sample No 
Layer zone 
sccm 
sccm 
sccm sccm 
sccm 
Torr 
W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
I-1 First layer 
20 
1 700 -- 15 1.2 
100 30 250 1.0 
(Lower speed 
zone 
film-forma- 
Second layer 
20 
1 700 30 -- 1.2 
100 15 250 0.5 
tion) zone 
I-2 First layer 
200 
20 300 -- 150 0.8 
100 6 250 1.0 
(Higher speed 
zone 
film-forma- 
Second layer 
200 
300 
300 -- 0.8 100 
3 250 0.5 
tion) zone 
__________________________________________________________________________ 
The C-content, the P element-content and the B element-content of thus 
formed first layer zone (2a) and second layer zone (2b) were measured with 
the results as shown in Table 21. 
TABLE 21 
______________________________________ 
Sample Value of x 
P element- 
B element- 
No Kind of layer 
in Si.sub.1-x C.sub.x 
content (ppm) 
content (ppm) 
______________________________________ 
I-1 Second layer 
0.1 -- 40 
zone 
First layer 
0.1 20 -- 
zone 
I-2 Second layer 
0.25 -- 40 
zone 
First layer 
0.25 20 -- 
zone 
______________________________________ 
The voltage-electric current characteristics of thus obtained a-SiC 
photoconductive members were measured with applying a voltage to the side 
of the Al electrode (30) and connecting the flat plate (29) to the earth 
side, as shown in FIG. 40, with the results as shown in FIGS. 53 and 54. 
FIG. 53 shows the voltage-electric current characteristics of the Sample 
No. I-1 and FIG. 54 shows the voltage-electric current characteristics of 
the Sample No. I-2. Referring to FIGS. 53 and 54, an axis of abscissa 
designates a voltage applied to the Al electrode (30), an axis of ordinate 
designating an electric current, and .smallcircle. marks designating a 
plot of measured values. 
In both FIG. 53 and FIG. 54 a plot of measured values for COMATIVE 
EXAMPLE was shown by .DELTA. marks. In every case, the PH.sub.3 gas 
(having a concentration of 40 ppm) was mixed at a flow rate of 15 sccm and 
a thickness of 1.0 micron was given under the film-forming conditions of 
the Sample No. C-1 in the formation of the first layer zone and the 
B.sub.2 H.sub.6 gas (having a concentration of 40 ppm) was mixed at a flow 
rate of 30 sccm and a thickness of 0.5 microns was given in the formation 
of the second layer zone to produce the a-SiC photoconductive layers. 
As obvious from FIGS. 53 and 54, with the a-SiC photoconductive members 
according to the present invention, even though the negative voltage is 
applied to the Al electrode (30), an electric current is hardly flown, 
but, in the case where the positive voltage is applied to the Al electrode 
(30), a remarkably large electric current is flown. 
EXAMPLE 26 
The same a-SiC photoconductive layer as in EXAMPLE 25 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) comprising hydrazone compounds 
dispersed therein in the same manner as in EXAMPLE 11 was formed to obtain 
a negative charge type electrophotographic sensitive member. 
Thus, electrophotographic sensitive members N, .smallcircle. corresponding 
to the a-SiC photoconductive layers (I-1), (I-2), respectively, were 
produced. 
The dark- and photoattenuation characteristics of the sensitive member N 
were measured with the results as shown in FIG. 55 and the spectral 
sensitivity characteristics were measured with the results as shown in 
FIG. 56. 
Referring to FIG. 55, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating a charge acceptance (volt), n 
designating a dark attenuation curve, and n-1, n-2 and n-3 designating a 
photoattenuation curve at an exposure wavelength of 400 nm, 450 nm and 550 
nm, respectively. 
As obvious from FIG. 55, the improvement of the electrifying capacity in 
comparison with the fourth invention was found. 
In addition, referring to FIG. 56, an axis of abscissa designates a 
wavelength, an axis of ordinate designating a photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member N. For comparison, the organic photosemiconductive layer 
was similarly formed on the a-SiC photoconductive layer shown in FIG. 53 
to produce an electrophotographic sensitive member. A plot of measured 
values for this sensitive member is shown by .DELTA. marks. 
As obvious from FIG. 56, the sensitive member N showed the higher 
photosensitivity than that in COMATIVE EXAMPLE, which was higher also 
than that in the fourth invention. 
In addition, the present inventors measured the dark- and photoattenuation 
characteristics as well as the spectral sensitivity characteristics of 
also the sensitive member .smallcircle. with the same effect as the 
sensitive member N in every case. 
EXAMPLE 27 
Next, the present inventors formed the first layer zone (2a) and the second 
layer zone (2b) in turn under the film-forming conditions shown in Table 
22 and formed two kinds of a-SiC photoconductive layers J-1, J-2 followed 
by forming the organic photosemiconductive layer (having a thickness of 
about 15 microns) comprising hydrazone compounds dispersed therein in the 
same manner as in EXAMPLE 11 to a negative charge type electrophotographic 
member. 
The B.sub.2 H.sub.6 gas marked with * is diluted with the H.sub.2 gas at a 
concentration of 40 ppm. 
TABLE 22 
__________________________________________________________________________ 
High-fre- 
Raw mate- 
Diluent 
Impurity 
quency 
rial gas 
gas gas pres- 
electric Temper- 
Thick- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
B.sub.2 H.sub.6 
sure 
power 
Time 
ature 
ness 
Sample No 
Layer zone 
sccm 
sccm 
sccm sccm Torr 
W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
J-1 First layer 
20 
1 700 -- 1.2 
100 30 250 1.0 
(Lower speed 
zone 
film-forma- 
Second layer 
20 
1 700 30 1.2 
100 15 250 0.5 
tion) zone 
J-2 First layer 
200 
20 300 -- 0.8 
100 6 250 1.0 
(Higher speed 
zone 
film-forma- 
Second layer 
200 
20 300 300 0.8 
100 3 250 0.5 
tion) zone 
__________________________________________________________________________ 
The dark- and photoattenuation characteristics as well as the spectral 
sensitivity characteristics of thus obtained two kinds of sensitive member 
were measured with the same results as in EXAMPLE 26. 
EXAMPLE 28 
The present inventors varied the flow rate of the PH.sub.3 gas and the flow 
rate of the B.sub.2 H.sub.6 gas in the production of an 
electrophotographic sensitive member corresponding to the a-SiC 
photoconductive layer J-2 to produce 15 kinds of electrophotographic 
sensitive member (sensitive members P-1 to P-15) with the P 
element-content of the first layer zone and the B element-content of the 
second layer zone varied as shown in Table 23. 
Sensitive members marked with * are outside of the scope of the present 
invention. 
TABLE 23 
______________________________________ 
P element- 
B element- 
content content 
Kind of 
of the first 
of the second 
Photo- Charge 
sensitive 
layer zone 
layer zone sensi- 
Residual 
accept- 
member (ppm) (ppm) tivity 
potential 
ance 
______________________________________ 
P-1 0 10 .DELTA. 
.DELTA. 
.largecircle. 
P-2 0 100 .circleincircle. 
.circleincircle. 
.circleincircle. 
P-3 100 3 .largecircle. 
.DELTA. 
.largecircle. 
P-4 50 0.5 x x .largecircle. 
P-5 1800 2 .largecircle. 
.largecircle. 
.largecircle. 
P-6 500 40 .circleincircle. 
.circleincircle. 
.circleincircle. 
P-7 2500 70 .circleincircle. 
.circleincircle. 
.circleincircle. 
P-8 4000 70 .largecircle. 
.circleincircle. 
.circleincircle. 
P-9 2500 200 .largecircle. 
.largecircle. 
.largecircle. 
P-10 4000 200 .largecircle. 
.largecircle. 
.largecircle. 
P-11 2500 400 .DELTA. 
.DELTA. 
.DELTA. 
P-12 1800 700 .DELTA. 
.DELTA. 
.DELTA. 
P-13 2500 1300 x x .DELTA. 
P-14 7000 200 x x .DELTA. 
P-15 13000 100 x x x 
______________________________________ 
As obvious from Table 23, the sensitive members P-1 to P-3 and P-5 to P-12 
showed the superior photosensitivity, the enhanced charge acceptance and 
the reduced residual potential. 
It is, however, found that the sensitive members P-4, P-13 and P-14 are 
inferior in photosensitivity and charge acceptance and the sensitive 
member P-15 is not improved in photosensitivity, charge acceptance and 
residual potential. 
Preferred Embodiments of the Sixth Invention 
EXAMPLE 29 
An Al flat plate (25 mm.times.50 mm), of which surface had been ground, was 
placed within the reaction tube of the glow-discharge decomposition 
apparatus and the first layer zone (2a) and the second layer zone (2b) 
were formed on said flat plate in turn under the high-speed film-forming 
conditions shown in Table 24. 
Subsequently, a disk-like Al electrode (having a diameter of 3 mm) was 
formed by the vacuum vapor deposition method to produce photoconductive 
members as shown in FIG. 40. 
The B.sub.2 H.sub.6 gas and the PH.sub.3 gas marked with * is diluted with 
the H.sub.2 gas at a concentration of 40 ppm, respectively. 
Numerical values marked with ** designate a flow rate of gases at the start 
of film-formation rand the finish of film- formation and show the gradual 
decrease. 
TABLE 24 
__________________________________________________________________________ 
High-fre- 
Raw mate- 
Diluent 
Impurity Gas 
quency 
rial gas 
gas gas pres- 
electric Temper- 
Thick- 
SiH.sub.4 
C.sub.2 H.sub.2 
H.sub.2 
PH.sub.3 
B.sub.2 H.sub.6 
sure 
power 
Time 
ature 
ness 
Sample No 
Layer zone 
sccm 
sccm 
sccm sccm sccm 
Torr 
W minute 
.degree.C. 
.mu.m 
__________________________________________________________________________ 
K-1 First layer 
20 
1 700 30 .fwdarw. 0 
-- 1.2 
100 30 250 1.0 
(Lower speed 
zone 
film-forma- 
Second layer 
20 
1 700 -- 30 1.2 
100 15 250 0.5 
tion) zone 
K-2 First layer 
200 
20 300 300 .fwdarw. 0 
0.8 
100 6 250 1.0 
(Higher speed 
zone 
film-forma- 
Second layer 
200 
20 300 -- 300 
0.8 
100 3 250 0.5 
tion) zone 
__________________________________________________________________________ 
The C-content, the maximum P element-content and the B element-content of 
thus formed first layer zone (2a) and second layer zone (2b) were measured 
with the results as shown in Table 25. 
TABLE 25 
______________________________________ 
Maximum 
Sample Value of x 
P element- 
B element- 
No Kind of layer 
in Si.sub.1-x C.sub.x 
content (ppm) 
content (ppm) 
______________________________________ 
K-1 First layer 
0.1 -- 40 
zone 
Second layer 
0.1 50 -- 
zone 
K-2 First layer 
0.25 -- 40 
zone 
Second layer 
0.25 50 -- 
zone 
______________________________________ 
The voltage-electric current characteristics of thus obtained a-SiC 
photoconductive members were measured with applying a voltage to the side 
of the Al electrode (30) and connecting the flat plate (29) to the earth 
side, as shown in FIG. 40, with the results as shown in FIGS. 57 and 58. 
FIG. 57 shows the voltage-electric current characteristics of the Sample 
No. K-1 and FIG. 58 shows the voltage-electric current characteristics of 
the Sample No. K-2. In addition, referring to FIGS. 57, 58, an axis of 
abscissa designates a voltage applied to the Al electrode (30), an axis of 
ordinate designating an electric current, and .smallcircle. marks 
designating a plot of measured values. 
In both FIG. 57 and FIG. 58 a plot of measured values for COMATIVE 
EXAMPLE is shown by .DELTA. marks. In every case, the flow rate of the 
PH.sub.3 gas (having a concentration of 40 ppm) was gradually reduced from 
30 sccm to 0 sccm and a thickness of 1.0 micron was given under the 
film-forming conditions for the Sample No. C-1 in the formation of the 
first layer zone and the B.sub.2 H.sub.6 gas (having a concentration of 40 
ppm) was mixed at a flow rate of 30 sccm and a thickness of 0.5 microns 
was given in the formation of the second layer zone to produce a-SiC 
photoconductive layers. 
As obvious from FIGS. 57 and 58, with the a-SiC photoconductive members 
according to the present invention, even though the negative voltage is 
applied to the Al electrode (30), an electric current is hardly flown, 
but, in the case where the positive voltage is applied to the Al electrode 
(30), a remarkably large electric current is flown. 
In addition, in the case where the positive voltage was applied, the 
electric current was increased in comparison with that in FIGS. 53 and 54 
of the fifth invention. 
EXAMPLE 30 
The same a-SiC photoconductive layer as in EXAMPLE 29 was formed on the Al 
substrate and then the organic photosemiconductive layer (having a 
film-thickness of about 15 microns) comprising hydrazone compounds 
dispersed therein in the same manner as in EXAMPLE 11 was formed to obtain 
negative charge type electrophotographic sensitive members. 
Thus, the electrophotographic sensitive member Q, R corresponding to the 
a-SiC photoconductive layer (K-1), (K-2), respectively, were produced. 
The dark- and photoattenuation characteristics of the sensitive member Q 
were measured with the results as shown in FIG. 59 and the spectral 
sensitivity characteristics were measured with the results as shown in 
FIG. 60. 
Referring to FIG. 59, an axis of abscissa designates an attenuation time 
(sec), an axis of ordinate designating a charge acceptance (volt), O 
designating a dark attenuation curve, and O-1, O-2 and O-3 designating a 
photoattenuation curve at an exposure wavelength of 400 nm, 450 nm and 550 
nm, respectively. 
As obvious from FIG. 59, the improvement of the electrifying capacity in 
comparison with that in the fourth invention was found and the reduction 
of the residual potential in comparison with that in the fifth invention 
was confirmed. 
In addition, referring to FIG. 60, an axis of abscissa designates a 
wavelength, an axis of ordinate designating a photosensitivity, and 
.smallcircle. marks designating a plot of measured values for the 
sensitive member Q. For comparison, the organic photosemiconductive layer 
was similarly formed on the a-SiC photoconductive layer shown in FIG. 57 
to produce an electrophotographic sensitive member. A plot of measured 
values for this sensitive member is shown by .DELTA. marks, 
As obvious from FIG. 60, the sensitive member Q showed the higher 
photosensitivity in comparison with that in COMATIVE EXAMPLE, which was 
higher than that in the fourth and fifth inventions. 
In addition, the present inventors measured the dark- and photoattenuation 
characteristics as well as the spectral sensitivity characteristics also 
for the sensitive member R in the same manner as in the present EXAMPLE 
with the same effect as that of the sensitive member Q. 
EXAMPLE 31 
In addition, the present inventors varied the maximum flow rate of the 
PH.sub.3 gas and the flow rate of the B.sub.2 H.sub.6 gas in the 
production of the sensitive member R to produce 14 kinds of 
electrophotographic sensitive member (sensitive members S-1 to S-14) with 
the maximum P element-content of the first layer zone and the B 
element-content in the second layer zone varied as shown in Table 26. 
Sensitive members marked with * are outside of the scope of the present 
invention. 
TABLE 26 
______________________________________ 
Maximum 
P element- 
B element- 
Kind of 
content content of 
sensi- of the first 
the second 
Photo Charge 
tive layer zone 
layer zone 
sensitiv- 
accept- 
Residual 
member (ppm) (ppm) ity ance potential 
______________________________________ 
S-1 5 20 .DELTA. 
.DELTA. 
.DELTA. 
S-2 5 100 .circleincircle. 
.circleincircle. 
.circleincircle. 
S-3 180 2 .largecircle. 
.largecircle. 
.largecircle. 
S-4 30 0.5 x x .largecircle. 
S-5 2000 2 .largecircle. 
.largecircle. 
.largecircle. 
S-6 600 40 .circleincircle. 
.circleincircle. 
.circleincircle. 
S-7 2000 50 .circleincircle. 
.circleincircle. 
.circleincircle. 
S-8 5000 70 .largecircle. 
.circleincircle. 
.circleincircle. 
S-9 2500 200 .largecircle. 
.largecircle. 
.largecircle. 
S-10 5000 200 .largecircle. 
.largecircle. 
.largecircle. 
S-11 2500 400 .DELTA. 
.DELTA. 
.DELTA. 
S-12 1500 700 .DELTA. 
.DELTA. 
.DELTA. 
S-13 1500 1300 x x .DELTA. 
S-14 12000 70 x x x 
______________________________________ 
As obvious from Table 26, the sensitive members S-1 to S-3 and S-5 to S-12 
showed the superior photosensitivity, the enhanced charge acceptance and 
the reduced residual potential. 
It is, however, found that the sensitive member S-4 is inferior in 
photosensitivity and charge acceptance and the sensitive members S-13 and 
S-14 are not improved in photosensitivity, charge acceptance and residual 
potential. 
Industrially Possible Availability 
As above described, in an electrophotographic sensitive member according to 
the present invention an a-SiC photoconductive layer is composed of 
elements, such as Si- and C element as well as H element or halogen 
element, said a-SiC photoconductive layer comprising a first layer zone 
and a second layer zone formed in turn, and said layer zones containing 
the IIIa group elements or the Va group elements in a quantity within an 
appointed range, whereby the high-capacity and high-quality 
electrophotographic sensitive member, of which photosensitivity can be 
improved, charge acceptance being able to be enhanced, and residual 
potential being able to be reduced, can be obtained.