Light receiving member

Abstract: The improvements in the light receiving members in which an aluminum material being used as the substrate for use in electrophotography and in other various devices. The improved light receiving member to be provided is char­ acterized in that a buffer layer functioning to improve the bondability between the aluminum substrate and a light re­ ceiving layer to be disposed thereon is disposed between the substrate and said light receiving layer. The improved light receiving member is satisfactorily free from various problems due to insufficient bondability between the aluminum substrate and the light receiving layer imposed thereon which are found in the conventional light receiving members.

Description: This invention relates to a light receiving member having a photoconductive layer formed of an amorphous material containing silicon and a substrate constituted principally of aluminium. For light receiving members for use in electrophotography and the like, public attention has been focused on . light receiving members that have a photoconductive layer formed of an amorphous material containing silicon atoms as the main constituent atoms and hydrogen atoms (hereinafter referred to as "A-Si:H") as disclosed in Unexamined Japanese Patent Publications Sho. 54 (1979) - 86341 and Sho. 56 (1981) - 83746 since said photoconductive layer has a high Vickers hardness in addition to having an excellent matching property in the photosensitive region in comparison with that in other kinds of light receiving member and it is not harmful to living things, including man, in use. Further, in recent years, a laser printer using the electrophotographic process in which a semiconductor laser having a wavelength of 770 to 800 nm is used as the light source has been tried to make practically usable. It is known that when there is used a light receiving member having a photoconductive layer formed of a silicon containing amorphous material, especially an A-Si material containing hydrogen atoms (H) and/or a halogen atoms (X) [hereinafter referred to as "A-Si(H,X)"] in such laser printer, it becomes to show a desired matching property with the semiconductor laser and to bring about a quick photoresponse because of its high photosensitivity in all the wavelength regions of light and especially because of its superior photosensitivity in the long wavelength region of light in comparision with that of the known light receiving member having a selenium light receiving layer. By the way, for the light receiving member as above mentioned, there has been proposed to dispose between the substrate and the photoconductive layer a high resistance intermediate layer formed of a non-monocrystalline material containing silicon atoms as the main constituent atoms and at least one kind of atom selected from oxygen atoms, carbon atoms and nitrogen atoms or/and a charge injection inhibition layer formed of a non-monocrystalline material containing hydrogen atoms and/or halogen atoms in addition to silicon atoms, and a conductivity controlling element of Group III or Group V of the Periodic Table (hereinafter referred to as "Group III element" and "Group V element" respectively) respectively aiming at inhibiting electrons from being injected into the photoconductive layer from the side of the substrate at the time when the light receiving member is engaged in electrification process and permitting the photocarriers, which will be generated in the photoconductive layer and move toward the substrate side at the time when received irradiation of electromagnetic waves, to pass through the substrate side from the photoconductive layer. There has been also proposed to dispose a layer functioning to absorb light in the long wavelength region (hereinafter referred to as "IR absorption layer") between the substrate and the photoconductive layer in order to eliminate problems to be often occurred in the case of conducting image exposure using the semiconductor laser as the light source for the above mentioned light receiving member that the light in the long wavelength region which could not be absorbed by the photoconductive layer reflects on the surface of the substrate to cause the occurrence of interference phenomena. As such IR absorption layer, there has been proposed such that is formed of an amorphous material containing at least one kind atom selected from silicon atom (Si), germanium atom (Ge) and tin atom (Sn). Now, Figure 2 is a schematic cross-sectional view illustrating the typical layer composition of the known light receiving member, in which are shown substrate 101, photoconductive layer 102 and high resistance intermediate layer, charge injection inhibition layer or IR absorption layer 103. And, for the electroconductive substrate for use in the known light receiving member having a photoconductive layer formed of an A-Si:H material or an A-Si(H,X), there have been used metals such as Aℓ, Ni, Cr, Mo, Au, Nb, Ta, V, Ti, Pt, Pt, etc. or alloys of two or more of these metals such as stainless steel. Among these metals and alloys, metallic materials the aluminium metal or alloys of which principal constituent is aluminium are most preferably used in the viewpoints of their lightness and treatment easiness and also in the economical viewpoint. And these light receiving members are generally prepared by forming on a substrate each of the foregoing IR absorption layer, charge injection inhibition layer, high resistance intermediate layer and photoconductive layer by means of vacuum evaporation, thermal induced chemical vapor deposition, plasma chemical vapor deposition and reactive sputtering. However, in the case of forming such layers on a substrate of which principal constituent is aluminium (hereinafter referred to as "aluminium substrate") using such film forming process, it is generally recognized that there are several problems as hereunder mentioned. That is, because the softening point of aluminium is in the range from 150°C to 200°C, when the aluminium substrate is heated to about 250°C and maintained at that temperature, a strain is produced on the aluminium substrate during the film forming operation. Further, because there is a difference of about one digit number between the thermal expansion coefficient of aluminium and that of the high resistance intermediate layer, charge injection inhibition layer or IR absorption layer to be formed thereon, cracks can be formed in such layer and sometimes this results in the layer peeling off from the substrate. In order to eliminate the above problems, it has been proposed that the temperature of the layer to be formed on the aluminium substrate is gradually elevated to a desired temperature while maintaining that substrate at a relatively low temperature. However, such method is accompanied with problems that a layer such as an A-Si:H layer to be formed becomes such that is insufficient in its photosensitivity, the characteristics are varied and the yield is decreased. Patent Abstracts of Japan, Vol.8, No.163 and Japanese Kokai 5958435 also has addressed the aforesaid problem of cracking and peeling. Therein is disclosed a light receiving member in which the substrate is of aluminium and the photoconductive layer is of amorphous material containing silicon atoms as the main constituent. An intermediate layer of aluminium or aluminium-silicon is interposed between the substrate and the photoconductive layer as a means of effecting strain relief. In the detailed example, the photoconductive layer is A-Si:H:0 and is produced by glow discharge decomposition of a gaseous mixture of silane and oxygen. The strain relief layer is a 2µm thick film of aluminium produced by plasma deposition using trimethyl aluminium as aluminium source. Against this background, various devices using a light receiving member have been greatly diversified. And there is an increased demand for providing a desirable light receiving member having the required layers being disposed on an aluminium substrate which is free from the problems due to the insufficient bondability between the substrate and the layer to be formed thereon and other problems as above mentioned on the known light receiving member, which has a desirable suitability for use in various devices and which also has a wealth of many practically applicable characteristics capable of satisfying various demands required for such various devices. This invention is aimed at eliminating the foregoing problems in the conventional light receiving member having a photoconductive layer formed of an amorphous material containing silicon in which an aluminium material being used as the substrate and providing an improved light receiving member being free from the foregoing problems including those due to the insufficient bondability between the aluminium substrate and the layer to be formed thereon, which has a desired suitability for use in various devices and which is capable of being mass-produced with a high yield. Another object of this invention to provide a desirable light receiving member having a photoconductive layer formed of an amorphous material containing silicon in which the aluminium substrate being used and the bondability between the aluminium substrate and any high resistance intermediate layer, charge injection inhibition layer or IR absorption layer included is improved significantly without hindering the functions required for such layers and which satisfies the foregoing demand. The present inventors have made earnest studies for overcoming the foregoing problems of conventional light receiving members and attaining the objects as described above and, as a result, have accomplished this invention based on the finding as described below. That is, as a result of earnest studies focusing on the improvements in the bondability between the aluminium substrate and a layer to be formed thereon in the conventional light receiving member having at least one layer selected from the group consisting of high resistance intermediate layer, charge injection inhibition layer and IR absorption layer, and a photoconductive layer in this order on the aluminium substrate, the present inventors have found that when an intermediate (buffer) layer formed of an amorphous material, polycrystalline material or other non-monocrystalline material containing aluminium atoms and at least one kind of the atoms which are the constituent atoms for the high resistance intermediate layer, charge injections inhibition layer or IR absorption layer is disposed between the aluminium substrate and the high resistance intermediate layer, charge injection inhibition layer or IR absorption layer, the bondability between the aluminium substrate and the above layer to be formed thereon can be improved significantly to thereby eliminate the foregoing problems which are found in the conventional light receiving member and the objects of this invention as described above can be satisfactorily attained. In accordance with the present invention there is provided: a light receiving member comprising: a substrate constituted principally of aluminium; an intermediate layer; and a photoconductive layer constituted by an amorphous material containing silicon atoms as the main constituent, hydrogen atoms and, optionally, halogen atoms and having a thickness 1 µm to 100 µm; in which member said intermediate layer comprises at least one of the following layers: (i) a high resistance layer constituted by a non-single crystalline material containing silicon atoms as main constituent, at least one of oxygen atoms, carbon atoms and nitrogen atoms and atoms of hydrogen and/or halogen, and having a thickness of 10 or 20 nm; (ii) a charge injection inhibition layer constituted by an amorphous material containing silicon atoms as main constituent, atoms of an element of either group III or group V of the Periodic Table, and which may also contain hydrogen and/or halogen atoms, and having a thickness of 0.03 to 15 µm; and (iii) an infrared light absorption layer constituted by a non-single crystalline material containing silicon atoms, germanium and/or tin atoms and which may contain hydrogen and/or halogen atoms, and having a thickness of 3nm to 50µm; wherein to improve bondability between said substrate and said intermediate layer or layers there is interposed a buffer layer constituted by a non-single crystalline material containing aluminium atoms, silicon atoms, and at least one other constituent of said intermediate layer, or layers, the buffer layer having a thickness of 1 to 10 nm. In the accompanying drawings: Fig. 1 is a schematic cross-sectional view illustrating a representative embodiment of a light receiving member to be provided according to this invention; Fig. 2 is a schematic cross-sectional view illustrating the typical conventional light receiving member; and Fig. 3 is a schematically explanatory view of a high frequency plasma deposition system for preparing a light receiving member according to this invention. The above-described and other objects, advantages, and features of the invention will become more apparent upon making reference to the following description, the claims and the drawings. The following is given by way of example only. Figure 1 is a schematic cross-sectional view illustrating a representative embodiment of a light receiving member to be provided according to this invention in which are shown substrate of which the principal constituent is aluminium material (hereinafter referred to as an "aluminium substrate") 101, photoconductive layer 102, high resistance intermediate layer, charge injection inhibition layer or IR absorption layer 103 and buffer layer 104. Substrate 101 The configuration of the aluminium substrate 101 of the light receiving member either an endless belt or a cylindrical form. And the thickness of the substrate is properly determined so that the light receiving member as desired can be formed. In the case where flexibility is required for the light receiving member, it can be made as thin as possible within a range capable of sufficiently providing the functions as the substrate. However, the thickness is usually greater than 10 µm in view of the fabrication and handling or mechanical strength of the substrate. Photoconductive Layer 102 The photoconductive layer 102 of the light receiving member is constituted with A-Si(H,X), and the halogen atoms (X) optionally to be incorporated in the layer, in case where necessary,can include fluorine, chlorine, bromine and iodine. And among these halogen atoms, fluorine and chlorine are particularly preferred. The amount of the hydrogen atoms (H), or the sum of the amounts for the hydrogen atoms and the halogen atoms (H+X) to be incorporated in the photoconductive layer is preferably 1 to 4 x 10 atomic %, more preferably, 5 to 3 x 10 atomic %. The photoconductive layer constituted with A-Si(H,X) may contain group III element or group V element respectively having a relevant function to control the conductivity of the photoconductive layer, whereby the photo-sensitivity of the layer can be improved. Specifically, the group III element can include B (boron), Al (aluminum), Ga (gallium), In (indium) and Tl (thallium), B and Ga being particularly preferred. The group V element can include, for example, P (phosphor), As (arsenic), Sb (antimony) and Bi (bismuth), P and Sb being particularly preferred. . The amount of the group III element or the group V element to be incorporated in the photoconductive layer 102 is preferably 1x10⁻³ to 1x10³ atomic ppm, more preferably, 5x10⁻² to 5x10² atomic ppm, and most preferably, 1x10⁻¹ to 2x10² atomic ppm. Further, in order to improve the quality of the photoconductor layer and to increase its dark resistance, at least one kind selected from oxygen atoms, carbon atoms and nitrogen atoms can be incorporated in the photoconductive layer. The amount of these atoms to be incorporated in the photoconductive layer is preferably 10 to 5x10⁵ atomic ppm, more preferably 20 to 4x10⁵ atomic ppm, and, most preferably, 30 to 3x10⁵ atomic ppm. The thickness of the photoconductive layer 102 is an important factor in order to effectively attain the object of this invention. The thickness of the photoconductive layer is, therefore, necessary to be carefully determined having due regards so that the resulting light receiving member becomes accompanied with desired characteristics. In view of the above, the thickness of the photoconductive layer 102 is preferably 1 to 100 µm, more preferably 3 to 80 µm, and most preferably 5 to 50 µm. High Resistance Intermediate Layer 103 The high resistance intermediate layer 103, if included, in the light receiving member, is to be disposed under the above mentioned photoconductive layer 102. The high resistance intermediate layer 103 is constituted with an A-Si(H,X) material containing at least one kind selected from oxygen atoms, carbon atoms and nitrogen atoms (hereinafter referred to as "A-Si(O,C,N)(H,X)"), polycrystlline Si(O,C,N) (H,X) material (hereinafter referred to as "poly-Si(O,C,N) (H,X)") or so-called non-monocrystalline material containing the above mentioned two kinds of materials (hereinafter referred to as "Non-Si(O,C,N) (H,X)"). (Note: So-called microlite silicon is classified in the category of A-Si). The high resistance intermediate layer 103 of the light receiving member functions to inhibit electrons from being injected into the photoconductive layer 102 from the side of the substrate 101 at the time when the light receiving member is engaged in electrification process and to permit the photocarriers, which will be generated in the photoconductive layer 102 and move toward the side of the substrate 101 when received irradiation of electromagnetic waves, to pass through the side of the substrate 101 from the photoconductive layer 102. In view of this, the amount of at least one kind of atoms selected from oxygen atoms, carbon atoms and nitrogen atoms to be incorporated into the high resistance intermediate layer 103 in the light receiving member of this invention is an important factor in order to effectively attain the objects of this invention. And it is preferably 10 to 5x10⁵ atomic ppm, preferably 20 to 4x10⁵ atomic ppm, and most preferably 30 to 3x10⁵ atomic ppm. Likewise, the thickness of the high resistance intermediate layer 103 is also an important factor, and is a thickness of 10 to 20 nm. Charge Injection Inhibition Layer 103 The charge injection inhibition layer, if included, in the light receiving member, is to be disposed under the above mentioned photoconductive layer 102. And the charge injection inhibition layer is constituted with an A-Si(H,X) material containing group III element or group V element [hereinafter referred to as "A-Si(III,V):(H,X)"], a poly-Si(H,X) material containing group III element or group V element [hereinafter referred to as "poly-Si(III,V):(H,X)"] or a non-monocrystalline material containing the above two materials [hereinafter referred to as "Non-Si(III,V):(H,X)"]. The charge injection inhibition layer 103 of the light receiving member functions to maintain an electric charge at the time when the light receiving member is engaged in electrification process and also to contribute to improving the photoelectrographic characteristics of the light receiving member. In view of the above, the amount of either the group III element or the group V element to be incorporated into the charge injection inhibition layer is an important factor therefor to efficiently exhibit the foregoing functions. Specifically, it is preferably 3 to 5x10⁴ atomic ppm, more preferably 50 to 1x10⁴ atomic ppm, and most preferably 1x10² to 5x10³ atomic ppm. As for the hydrogen atoms (H) and the halogen atoms (X) to be incorporated into the charge injection inhibition layer, the amount of the hydrogen atoms (H), the amount of the halogen atoms (X) or the sum of the amounts of the hydrogen atoms and the halogen atoms (H+X) is preferably 1x10³ to 7x10⁵ atomic ppm, and most preferably, 1x10³ to 2x10⁵ atomic ppm in the case where the charge injection inhibition layer is constituted with a poly-Si(III,V):(H,X) material and 1x10⁴ to 6x10⁵ atomic ppm in the case where the charge injection inhibition layer is constituted with an A-Si(III,V) : (H,X) material. Further, it is possible to incorporate at least one kind of atoms selected from oxygen atoms, nitrogen atoms and carbon atoms into the charge injection inhibition layer aiming at improving the bondability of the charge injection inhibition layer not only with the buffer layer 104 but also with the photoconductive layer 102. In that case, the amount of one or more of these atoms to be incorporated in that layer is preferably 10 to 5x10⁵ atomic ppm, more preferably 20 to 4x10⁵ atomic ppm, and most preferably, 30 to 3x10⁵ atomic ppm. The thickness of the charge injection inhibition layer 103 in the light receiving member is an important factor also in order to make the layer to efficiently its functions. In view of the above, the thickness of the charge injection inhibition layer 103 is preferably 0.03 to 15 µm, more preferably 0.04 to 10 µm, and most preferably, 0.05 to 8 µm. IR Absorption Layer 103 The IR absorption layer 103, if included, in the light receiving member, is to be disposed under the foregoing photoconductive layer 102. And the IR absorption layer is constituted with an A-Si(H,X) material containing germanium atoms (Ge) or/and tin atoms (Sn) [hereinafter referred to as "A-Si(Ge,Sn) (H,X)"], a poly-Si(H,X) material containing germanium atoms (Ge) or/and tin atoms (Sn) [hereinafter referred to as "poly-Si(Ge,Sn) (H,X)"] or a non-monocrystalline material containing the above two materials [hereinafter referred to as "Non-Si(Ge,Sn) (H,X)"]. As for the germanium atoms (Ge) and the tin atoms (Sn) to be incorporated into the IR absorption layer, the amount of the germanium atoms (Ge), the amount of the tin atoms (Sn) or the sum of the amounts of the germanum atoms and the tin atoms (Ge+Sn) is preferably 1 to 1x10⁶ atomic ppm, more preferably 1x10² to 9x10⁵ atomic ppm, and most preferably, 5x10² to 8x10⁵ atomic ppm. And, the thickness of the IR absorption layer 103 is preferably 3nm (30 Å) to 50 µm, more preferably 4 nm (40 Å) to 40 µm, and most preferably, 5 nm (50 Å) to 30 µm. Now, in the light receiving member it is possible to dispose the aforementioned charge injection inhibition layer between the above IR absorption layer and the aforementioned photoconductive layer 102. Further, in the light receiving member it is possible to dispose an intermediate layer other than the aforementioned high resistance intermediate layer between the above IR absorption layer or the aforementioned charge injection inhibition layer and the photoconductive layer. In that case, said intermediate layer is one that is constituted with an A-Si material, a poly-Si material or a Non-Si material respectively containing at least one kind atoms selected from oxygen atoms, carbon atoms and nitrogen atoms in the amount of preferably 10 to 5x10⁵ atomic ppm, more preferably 20 to 4x10⁵ atomic ppm, or most preferably 30 to 3x10⁵ atomic ppm. And the thickness of such intermediate layer is preferably 0.03 to 15 µm, more preferably 0.04 to 10 µm, and most preferably, 0.05 to 8 µm. Further in addition, in the light receiving member it is possible to make the above mentioned IR absorption layer to be such that can function not only as the IR absorption layer but also as the charge injection inhibition layer. In that case, the object can be attained by incorporating either the group III element or the group V element which is the constituent of the aforementioned charge injection inhibition layer or at least one kind atoms selected from oxygenatoms, carbon atoms and nitrogen atoms into the above IR absorption layer. Buffer Layer 104 The buffer layer 104 in the light receiving member is to be disposed between the aluminium substrate 101 and the high resistance intermediate layer, the charge injection inhibition layer or the IR absorption layer. The buffer layer 104 in the light receiving member functions to improve the bondability between the aluminium substrate 102 and the high resistance intermediate layer, the charge injection inhibition layer or the IR absorption layer without hindering the original functions which are to be exhibited by such layer and contributes to increasing the yield of a desired light receiving member. The buffer layer 104 is constituted with an amorphous, polycrystalline or other non-monocrystalline materials respectively containing aluminium atoms and constituent atoms of the high resistance . intermediate layer, the charge injection inhibition layer or the IR absorption layer. The thichkness of the buffer layer 104 in the light receiving member is also important, and is a thickness of 1 to 10 nm. Surface Layer In the light receiving member possible to dispose an appropriate surface layer on the foregoing photoconductive layer 102. In that case, the surface layer can be such that is constituted with an A-Si(H,X) material containing at least one kind atoms selected from oxygen atoms, carbon atoms and nitrogen atoms, that is an A-Si(O,C,N)(H,X) material. To dispose such surface layer on the photoconductive layer 102 contributes to improving the humidity resistance, deterioration resistance upon repeating use, breakdown voltage resistance, use-environmental characteristics and durability of the light receiving member And in the case of disposing a surface layer formed of an A-Si(O,C,N) (H,X) material on the foregoing photconductive layer 102, since the surface layer contains silicon atoms as the constituent atoms which are contained in the photoconductive layer as the main constituent atoms, the interface between the two layers is always maintained in a chemically stable state. As for the oxygen atoms, carbon atoms and nitrogen atoms which are selectively contained in the surface layer, the above mentioned various characteristics will be increased with increasing their amount, but in the case of incorporating an excessive amount of such atoms into the surface layer, not only the layer quality but also the electric and mechanical characteristics will be undesirably declined. In view of the above, the amount of at least one kind atoms selected from oxygen atoms, carbon atoms and nitrogen atoms is preferably 0.001 to 90 atomic %, more preferably 1 to 90 atomic %, and most preferably,10 to 90 atomic %. The thickness of the surface layer in the light receiving member . is appropriately determined depending upon the desired purpose. It is, however, also necessary that the thickness be determined in view of relative and organic relationship in accordance with the amounts of the constituent atoms to be contained in the layer or the characteristics required in the relationship with the thickness of other layer. Further, it should be determined also in economical viewpoints such as productivity or mass productivity. In view of the above, the thickness of the surface layer is preferably 3x10⁻³ to 30 µm, more preferably, 4x10⁻³ to 20 µm, and, most preferably, 5x10⁻³ to 10 µm. For the formation of each of the above mentioned constituent layers to prepare the light receiving member any of the known film forming processes such as thermal induced chemical vapor deposition process, plasma chemical vapor deposition process, reactive sputtering process and light induced chemical vapor deposition process can be selectively employed. And among these processes, the plasma chemical vapor deposition process is the most appropriate. For instance, in the case of forming a layer composed of a poly-Si(Ge,Sn) (H,X) by means of plasma chemical vapor deposition (commonly abbreviated to "plasma CVD"), the film forming operation is practiced while maintaining the substrate at a temperature from 400 to 450°C in a deposition chamber. In another example of forming a layer composed of a poly-Si(Ge,Sn) (H,X), firstly, an amorphous-like film is formed on the substrate being maintained at about 250°C in a deposition chamber by means of plasma CVD, and secondly the resultant film is annealed by heating the substrate at a temperature of 400 to 450°C for-about 20 minutes or by irradiating laser beam onto the substrate for about 20 minutes to thereby form said layer. This invention will be described more specifically while referring to Examples 1 through 11, but it is not intended to limit the scope of the invention only to these examples. Figure 3 is a schematically explanatory view of a high frequency plasma deposition system for preparing a light receiving member according to this invention. Referring Figure 3, there is shown an aluminium cylinder 301' placed on a substrate holder 301 having a electric heater 303 being electrically connected to power source 304. The substrate holder 301 is mechanically connected through a rotary shaft to a motor 302 so that the aluminium cylinder 301' may be rotated. The electric heater 303 surves to heat the aluminum cylinder 301' to a predetermine temperature and maintain it at that temperature, and it also serves to aneal the deposited film. 305 stands for the side wall of the deposition chamber. The side wall 305 acts as a cathode, and the aluminum cylinder 301 is electrically grounded and acts as an anode. High frequency power source 306 is electrically connected through matching box 307 to the side wall 305 and supplies a high frequency power to the side wall 305 as the cathode to thereby generate a discharge between the cathodeand the anode. 308 stands for a raw material gas feed pipe having a plurality of gas liberation holes to liberate a raw material gas toward the aluminum cylinder 301. 309 stands for exhaust system having a diffusion pump and mechanical booster pump to evacuate the air in the deposition chamber. The outer wall face of the deposition chamber is protected by shield member 310. The other end of each of the raw material gas feed pipes 308, 308, ... is connected to raw material gas reservoirs 311, 312, 313, 314, 315 and 316. An appropriate raw material gas is reserved in each of the raw material gas reservoirs 311 through 316. For example, there are reserved H₂ gas in the gas reservoir 311, silane (SiH₄) gas in the gas reservoir 312, B₂H₆ gas in the gas reservoir 313, GeH₄ gas in the gas reservoir 314, CH₄ gas in the gas reservoir 315 and He gas in the gas reservoir 316. 317 stands for bubbling vessel containing Aℓ (C₂H₅)₃ which is bubbled by blowing He gas from the gas reservoir 316 thereinto to thereby cause a gas containing Aℓ(C₂H₅)₃ From the gas reservoirs 311 through 316 and from the bubbling vessel 317, corresponding raw material gases are supplied into the raw material gas feed pipe 308 through main valves 321 through 327,inlet valves 331 through 337, mass flow controllers 341 through 347 and exit valves 351 through 357. Example 1 A light receiving member having a buffer layer, a high resistant intermediate layer, a photoconductive layer and a surface layer on an aluminium cylinder was prepared using the apparatus shown in Figure 3. Prior to entrance of the raw material gases into the deposition chamber, all the main valves 321 through 326 of the gas reservoirs 311 through 316 and the main valve 327 were closed, and the mass flow controllers 341 through 347, the inlet valves 331 through 337 and the exit valves 351 through 357 were opened. Then, the related inner atmosphere was brought to a vacuum of 10⁻⁵ Pa (10⁻⁷ Torr) by operating the diffusion pump of the exhaust system 309. At the same time, the electric heater 303 was activated to uniformly heat the aluminium cylinder 301' to about 250°C and the aluminium cylinder was maintained at that temperature. Thereafter, closing all the inlet valves 331 through 337 and the exit valves 351 through 357 and opening the gas reservoirs 311 through 316, the secondary pressure of each of the main valves 321 through 327 was adjusted to be 15 kg/cm² using the booster pump in stead of the diffusion pump. Then, regulating the corresponding valves, SiH₄ gas from the gas reservoir 312, CH₄ gas from the gas reservoir 315 and a gas containing Aℓ(C₂H₅)₃ generated by blowing He gas into the bubbling vessel 317 (He/Aℓ(C₂H₅)₃=10/1) were fed into the deposition chamber at a flow rate of 100 SCCM, 30 SCCM and 10 SCCM respectively. After the flow rates of these gases became stable, the high frequency power source 302 was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas in the deposition chamber. This state was maintained to form a layer to be the buffer layer of 1 nm (10Å) in thickness on the aluminium cylinder. Successively, the above procedures were repeated, except that the introduction of the gas containing Aℓ(C₂H₅)₃ was stopped by closing the exit valve 357, to thereby form a layer to be the high resistant intermediate layer of 10 nm (100 Å)in thickness on the previously formed buffer layer. Then, closing the exit valve 355 to stop the introduction of CH₄ gas and opening the exit valve 351 to introduce H₂ gas, the H₂ gas and the SiH₄ gas were together introduced into the deposition chamber at a flow rate of 300 SCCM and 150 SCCM respectively to produce thereby a layer composed of A-Si:H to be the photoconductive layer of 20 µm in thickness on the previously formed high resistant intermediate layer. Finally, switching off the high frequency power source 302 and closing the exit valve 351 to stop the introduction of H₂ gas, the SiH₄ gas and the CH₄ gas were together introduced into the deposition chamber, wherein the flow rate for the SiH₄ gas was adjusted to 35 SCCM and the CH₄ gas was adjusted to a flow ratio of SiH₄/CH₄=1/30. After the flow rates of these gases became stable, the high frequency power source was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas. This state maintained to form a layer composed of A-Si:C:H to be the surface layer of 0.5 µm in thickness on the previously formed photoconductive layer. The high frequency power source was switched off, the related exit valves for the raw material gases were closed, the electric heater was switched off, and the vacuum atmosphere in the deposition chamber was released to atmospheric pressure. After the aluminium cylinder was cooled to room temperature, it was taken out from the deposition chamber. The thus obtained light receiving member was applied to positive corona discharge with a power source voltage of 5.0 KV for 0.3 second, and soon after this, the image exposure was conducted by irradiating an exposure quantity of 0.7 lux.sec through a transparent test chart using a tungsten lamp as a light source. Then, the image was developed with a negatively charged toner (containing a toner and a toner carrier) in accordance with the cascade method to develop an excellent toner image on the member surface. The developed image was transferred to a transfer paper by applying positive corona discharge with a power source voltage of 5.0 KV and then fixed so that an extremely sharp image with a high resolution was obtained. It was also found that defects chiefly due to insufficient contact between the intermediate layer and the substrate which are often found in the known light receiving member were remarkably eliminated and the yield was improved because of disposing the buffer layer. Example 2 The procedures of Example 1 were repeated, except that NH₃ gas was used instead of the CH₄ gas and the film forming conditions were changed as shown in Table 1 to thereby obtain a desirable light receiving member. Example 3 A light receiving member having on an aluminum cylinder a buffer layer, a high resistant intermediate layer and a photoconductive layer was prepared under the film forming conditions shown in Table 1 in the same way as in Example 1 wherein O₂ gas was used in stead of the CH₄ gas. In this example, since O₂ gas is highly reactive with SiH₄ gas, the O₂ gas was fed through an independent feed pipe (not shown in Figure 3) into the deposition chamber. Example 4 The same procedures of Example 1 were repeated, except that the film forming conditions were changed as shown in Table 1, to thereby prepare a light receiving member having a buffer layer, a high resistant intermediate layer and a photoconductive layer on analuminium cylinder. As a result of conducting various evaluations on the light receiving members obtained in Examples 2 to 4 in accordance with the same procedures as in Example 1, it was found for each of the light receiving members that the bondability of the intermediate layer with the aluminium cylinder has been remarkably improved and it has a wealth of practically applicable photoelectric characteristics. Example 5 A layer containing aluminium atoms and silicon atoms of 10 nm (100Å) in thickness to be the buffer layer was formed on an aluminium cylinder by a reactive sputtering process using an Aℓ wafer and a Si wafer as targets. Thereafter, three successive layers to be the high resistant intermediate layer, photoconductive layer and surface layer were continuously formed on the previously formed buffer layer in the same was as in Example 1 using the apparatus shown in Figure 3 to thereby obtain a light receiving member. As a result of conducting various evaluations on the resultant light receiving member, it was found that the bondability of the intermediate layer for the resultant light receiving member has been remarkably improved, and the light receiving member is desirably usable in electrophotography since it was a wealth of practically applicable electrophotographic characteristics. Example 6 A light receiving member having a buffer layer, charge injection inhibition layer, photoconductive layer and surface layer on an aluminum cylinder using the apparatus shown in Figure 3. Prior to entrance of the raw material gases into the deposition chamber, all the main valves 321 through 326 of the gas reservoirs 311 through 316 and the main valve 327 were closed, and the mass flow controllers 341 through 347, the inlet valves 331 through 337 and the exit valves 351 through 357 were opened. Then, the related inner atmosphere was brought to a vacuum of 10⁻⁵ (10⁻⁷) by operating the diffusion pump of the exhaust system 309. At the same time, the electric heater 303 was activated to uniformly heat the aluminum cylinder 301' to about 250°C and the aluminum cylinder was maintained at that temperature. Thereafter, closing all the inlet valves 331 through 337 and the exit valves 351 through 357 and opening the gas reservoirs 311 through 316, the secondary pressure of each of the main valves 321 through 327 was adjusted to be 15 kg/cm² using the booster pump in stead of the diffusion pump. Then, regulating the corresponding valves, SiH₄ gas from the gas reservoir 312, CH₄ gas from the gas reservoir 315 and a gas containing Aℓ(C₂H₅)₃ generated by blowing He gas into the bubbling vessel 317 (He/Aℓ(C₂H₅)₃=10/1) were fed into the deposition chamber at a flow rate of 100 SCCM, 30 SCCM and 10 SCCM respectively. After the flow rates of these gases became stable, the high frequency power source 302 was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas in the deposition chamber. This state was maintained to form a layer to be the buffer layer of 10 nm (100 Å) in thickness on the aluminium cylinder. Successively, closing the valves 356 357 to stop the introduction of the gas containing Aℓ(C₂H₅)₃, the mass flow controller 341 was adjusted to 300 SCCM and H₂ gas from the gas reservoir 311 was fed into the deposition chamber by opening the related valves. At the same time, the mass flow controller 342 relative to SiH₄ gas was adjusted to 150 SCCM and the mass flow controller 343 was adjusted to such flow rate that the amount to be fed of B₂H₆ gas from the gas reservoir 313 could be a 1600 vol.ppm. After the inner pressure of the deposition chamber became stable at about 2.7x10 Pa (0.2 Torr), the high frequency power source 302 was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas in the deposition chamber. This state maintained to form a layer composed of a p-type A-Si:H to be the charge injection inhibition layer of 5 µm in thickness on the previously formed buffer layer. Successively, not switching off the high frequency power source, the above procedures were repeated, except that the introduction of the B₂H₆ gas was stopped by closing the valves 333 and 353, to thereby form a layer composed of A-Si:H to be the photoconductive layer of 20 µm in thickness. Then, switching off the high frequency power source once, the introduction of the H₂ gas was stopped by closing the valve 351 and CH₄ gas from the gas reservoir 315 was fed. At that time, the flow rate of the SiH₄ gas was changed to 35 SCCM and the flow ratio of the SiH₄ gas to the CH₄ gas was adjusted to be a SiH₄/CH₄=1/30. After the flow rates of these gases became stable, the high frequency power source was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas. This state continued to form a layer composed of A-Si:C:H to be the surface layer of 0.5 µm in thickness on the previously formed photoconductive layer whereby a light receiving member was prepared. The high frequency power source was switched off, the related exit valves for the raw material gases were closed, the electric heater was switched off, and the vacuum atmosphere in the deposition chamber was released to atmospheric pressure. After the aluminium cylinder being cooled to room temperature, it was taken out from the deposition chamber. The thus obtained light receiving member was applied to positive corona discharge with a power source voltage of 5.0 KV for 0.3 second, and soon after this, the image exposure was conducted by irradiating an exposure quantity of 0.7 lux.sec through a transparent test chart using a tungsten lamp as a light source. Then, the image was developed with a negatively charged toner (containing a toner and a toner carrier) in accordance with the cascade method to develop an excellent toner image on the member surface. The developed image was transferred to a transfer paper by applying positive corona discharge with a power source voltage of 5.0 KV and then fixed so that an extremely sharp image with a high resolution was obtained. It was also found that defects chiefly due to insufficient contact between the charge injection inhibition layer and the substrate which are often found in the known light receiving member were remarkably eliminated and the yield was improved because of disposing the buffer layer. Example 7 The produces of Example 6 were repeated, except that PH₃ gas was used in stead of the B₂H₆ gas to be used in the case of forming the charge injection inhibition layer and its flow amount was controlled to be 500 vol.ppm. against the flow amount of the SiH₄ gas, to thereby prepare a light receiving member. As a result of conducting the same image forming evaluations as in Example 6 on the resultant light receiving member, it was found that the light receiving member has a wealth of practically applicable photoelectrographic characteristics. It was also found that defects chiefly due to insufficient contact between the intermediate layer and the substrate which are often found in the known light receiving member were remarkably eliminated and the yield was improved because of disposing the buffer layer. Example 8 A light receiving member having a buffer layer, IR absorption layer, photoconductive layer and surface layer on an aluminium cylinder was prepared using the apparatus shown in Figure 3. Prior to entrance of the raw material gases into the deposition chamber, all the main valves 321 through 326 of the gas reservoirs 311 through 316 and the main valve 327 were closed, and the mass flow controllers 341 through 347, the inlet valves 331 through 337 and the exit valves 351 through 357 were opened. Then, the related inner atmosphere was brought to a vacuum of 10⁻⁵ (10⁻⁷ Torr) by operating the diffusion pump of the exhaust system 309. At the same time, the electric heater 303 was activated to uniformly heat the aluminium cylinder 301' to about 250°C and the aluminium cylinder was maintained at that temperature. Thereafter, closing all the inlet valves 331 through 337 and the exit valves 351 through 357 and opening the gas reservoirs 311 through 316, the Secondary pressure of each of the main valves 321 through 327 was adjusted to be 15 kg/cm² using the mechanical booster pump in stead of the diffusion pump. Then, regulating the corresponding valves, SiH₄ gas from the gas reservoir 312, CH₄ gas from the gas reservoir 315 and a gas containing Aℓ(C₂H₅)₃ generated by blowing He gas into the bubbling vessel 317 (He/Aℓ(C₂H₅)₃= 10/1) were fed into the deposition chamber at a flow rate of 100 SCCM, 30 SCCM and 10 SCCM respectively. After the flow rates of these gases became stable, the high frequency power source 302 was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas in the deposition chamber. This state was maintained to form a layer to be the buffer layer of 1 nm (10 Å) in thickness on the aluminium cylinder. Successively, switching off the high frequency power source 302 and closing the valves 356, 357 to stop the introduction of the gas containing Aℓ(C₂H₅)₃, the mass flow controller 341 was adjusted to 300 SCCM and H₂ gas from the gas reservoir 311 was fed into the deposition chamber by opening the related valves. At the same time, the mass flow controller 343 relative to GeH₄ gas was adjusted to 150 SCCM to feed GeH₄ gas from the gas reservoir 313 in the deposition chamber. After the inner pressure of the-deposition chamber became stable at 2.7x10 Pa (0.2 Torr), the high frequency power source 302 was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas. This statewasmaintained to form a layer composed of A-SiGe:C:H to be the IR absorption layer on the previously formed buffer layer. Continuing to apply said discharge energy, the above procedures were repeated, except that the introduction of the GeH₄ gas was stopped by closing the valves 333 and 353 and the mass flow controller 342 relative to the SiH₄ gas adjusted to 150 SCCM, to thereby form a layer composed of A-Si:H to be the photoconductive layer of 20 µm in thickness on the previously formed IR absorption layer. Then, switching off the high frequency power source 302 once, the introduction of the H₂ gas was stopped by closing the valves 331 and 351 and CH₄ gas from the gas reservoir 315 was fed. At that time, the flow rate of the SiH₄ gas was changed to 35 SCCM and the flow ratio of the SiH₄ gas to the CH₄ gas was adjusted to be a SiH₄/CH₄=1/30. After the flow rates of these gases became stable, the high frequency power source was switched on to apply a discharge energy of 150 W resulting in generating gas plasmas. This state was A-Si:C:H to be the surface layer of 0.5 µm in thickness on the previously formed photoconductive layer whereby a light receiving member was prepared. The high frequency power source 302 was switched off, the related exit valves for the raw material gases were closed, the electric heater was switched off, and the vacuum atmosphere in the deposition chamber was released to atmospheric pressure. After the aluminium cylinder being cooled to room temperature, it was taken out from the deposition chamber. The thus obtained light receiving member was applied to positive corona discharge with a power source voltage of 5.0 KV for 0.3 second, and soon after this, the image exposure was conducted by irradiating an exposure quantity of 0.7 lux.sec through a transparent test chart using a tungsten lamp as a light source. Then, the image was developed with a negatively charged toner (containing a toner and a toner carrier) in accordance with the cascade method to develop an excellent toner image on the member surface. The developed image was transferred to a transfer paper by applying positive corona discharge with a power source voltage of 5.0 KV and then fixed so that an extremely sharp image with a high resolution was obtained. It was also found that defects chiefly due to insufficient contact between the intermediate layer and the substrate which are often found in the known light receiving member were remarkably eliminated and the yield was improved because of disposing the buffer layer. Example 9 The procedures of Example 8 were repeated, except that the layer forming conditions for the IR absorption layer were changed as shown in Table 2 to form a layer composed of A-Ge:Si:H instead of the A-SiGe:C:H, to thereby obtain a light receiving layer. As a result of forming images using the resultant light receiving member by the same manner as in Example 8, there were obtained extremely clear visible images. Layer Gas used Flow rate Layer thickness High frequency power IR H₂ gas 300 SCCM absorption layer SiH₄ gas 75 SCCM 3 µm 150 W GeH₄ gas 75 SCCM Example 10 The procedures of Example 8 were repeated, except that the layer forming conditions for the IR absorption layer were changed as shown in Table 3 to form a layer composed of poly-Si:Ge:H:F instead of the A-SiGe:C:H layer, to thereby a light receiving member. As a result of forming images using the resultant light receiving member by the same manner as in Example 8, there were obtained extremely clear visible images. Layer Gas used Flow rate Layer thickness High frequency power IR H₂ gas 300 SCCM absorption layer SiH₄ gas 60 SCCM 1 µm 200 W GeH₄ gas 60 SCCM SiF₄ gas 30 SCCM Example 11 The procedures of Example 8 were repeated, except that the layer forming conditions for the IR absorption layer were changed as shown in Table 4 to form a layer composed of A-Si:Sn:H instead of the A-SiGe:C:H layer, to thereby prepare a light receiving member. As a result of forming images using the resultant light receiving member by the same manner as in Example 8, there were obtained extremely clear visible images. Layer Gas used Flow rate Layer thickness High frequency Power IR H₂ gas 300 SCCM absorption layer SiH₄ gas 75 SCCM 3 µm 150 W SnH₄ gas 75 SCCM

Claims: A light receiving member comprising: a substrate constituted principally of aluminium; an intermediate layer; and a photoconductive layer constituted by an amorphous material containing silicon atoms as the main constituent, hydrogen atoms and, optionally, halogen atoms and having a thickness of 1 to 100 µm; in which member said intermediate layer comprises at least one of the following layers: (i) a high resistance layer constituted by a non-single crystalline material containing silicon atoms as main constituent, at least one of oxygen atoms, carbon atoms and nitrogen atoms and atoms of hydrogen and/or halogen, and having a thickness of 10 or 20 nm; (ii) a charge injection inhibition layer constituted by an amorphous material containing silicon atoms as main constituent, atoms of an element of either group III or group V of the Periodic Table, and which may also contain hydrogen and/or halogen atoms, and having a thickness of 0.03 to 15 µm; and (iii) an infrared light absorption layer constituted by a non-single crystalline material containing silicon atoms, germanium and/or tin atoms and which may contain hydrogen and/or halogen atoms, and having a thickness of 3nm to 50µm; wherein to improve bondability between said substrate and said intermediate layer or layers there is interposed a buffer layer constituted by a non-single crystalline material containing aluminium atoms, silicon atoms, and at least one other constituent of said intermediate layer, or layers, the buffer layer having a thickness of 1 to 10 nm. A member as claimed in claim 1 wherein said intermediate layer is comprised of said charge injection inhibition layer (ii) and said member further comprises the high resistance intermediate layer (i) which is disposed between said charge injection inhibition layer and said photoconductive layer. A member as claimed in claim 1 wherein said intermediate layer is comprised of said infrared light absorption layer (iii) and said member further comprises the charge inhibition intermediate layer (ii) which is disposed between said infrared light absorption layer and said photoconductive layer. A member as claimed in claim 3 or in claim 1 wherein said intermediate layer is comprised of said infrared light absorption layer (iii) and/or said charge injection inhibition layer (ii), wherein said member further comprises the high resistance intermediate layer (i) which is disposed either between said infrared absorption layer and said photoconductive layer or between said charge injection inhibition layer and said photoconductive layer. A member as claimed in claim 1 wherein said intermediate layer is comprised of said charge injection inhibition layer (ii) and also includes atoms of oxygen, nitrogen and/or carbon. A member as claimed in any preceding claim wherein said member also comprises a surface layer disposed on said photoconductive layer which surface layer is constituted by an amorphous silicon material containing at least one of carbon atoms, oxygen atoms and nitrogen atoms, and hydrogen and/or halogen.

Inventors: AMADA HIROSHI, SHIRAI NAOKO, TAKEI TETSUYA, AMADA, HIROSHI, SHIRAI, NAOKO, TAKEI, TETSUYA
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1987
Main classification: G03G5
IPC codes: G03G5