Abstract:
An electroluminescence device and a display device including an electroluminescence device are provided. The electroluminescence device includes an anode including silver, wherein at least a portion of the anode substantially extends in a horizontal direction; a first layer provided over the anode; an organic layer including a luminescent layer; a cathode provided over the organic layer; and an insulating layer provided over an end portion of the anode and an end portion of the first layer, wherein at least a portion of the cathode substantially extends in the horizontal direction in a light emission region, wherein a surface of the insulating layer has a curved portion, and wherein at least a portion of the cathode within a region of the insulating layer above the curved portion extends along a first angled upward direction between the horizontal direction and the thickness direction of the anode.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of U.S. application Ser. No. 14/967,548, filed Dec. 14, 2015, which is a continuation of U.S. application Ser. No. 14/567,290, filed Dec. 11, 2014, which is a continuation of U.S. application Ser. No. 11/899,431, filed Sep. 6, 2007, which is a continuation of U.S. application Ser. No. 10/399,030, filed Apr. 11, 2003, which is a U.S. National stage of International Application No. PCT/JP02/06354, filed Jun. 25, 2002, which claims priority to and the benefit of Japanese Application Serial No. 2001-264410, filed Aug. 31, 2001, the entire content of each of which is hereby incorporated by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present application relates to an electroluminescence device including one or more organic layers including a luminescent layer between an anode and a cathode, and emitting light generated specifically in the luminescent layer, and a method of manufacturing the same. 
       BACKGROUND 
       [0003]    In recent years, organic EL displays using an organic electroluminescence device as an alternative to liquid crystal displays have become a focus of attention. The organic EL displays are of a self-luminous type, so it is considered that the organic EL displays have advantages of a wide viewing angle, low power consumption and adequate response to high-definition high-speed video signals. Therefore, the organic EL displays have been developed to achieve the practical use thereof. 
         [0004]      FIG. 6  shows a configuration of the organic electroluminescence device. The organic electroluminescence device comprises an anode  112 , an organic layer  115  including a hole injection layer  115 A, a hole transport layer  115 B and a luminescent layer  115 C, and a cathode  116  laminated in this order on a substrate  111 . Although light generated in the luminescent layer  115 C may be emitted from the substrate  111 , as shown in  FIG. 6 , the light may be emitted from the cathode  116 . 
         [0005]    When the light is emitted from the cathode  116 , it is often the case that the anode  112  comprises a metal such as chromium (Cr), and the cathode  116  comprises a transparent conductive material such as a compound of indium (In), tin (Sn) and oxygen (O) (ITO; indium tin oxide). The light generated in the luminescent layer  115 C may be directly emitted through the cathode  116  as indicated by an arrow  117  in  FIG. 6 , and as indicated by an arrow  118 , the light may be reflected on the anode  112  once and then emitted through the cathode  116 . 
         [0006]    However, conventionally, the anode  112  comprises chromium or the like, so there is a problem that light absorptance by the anode  112  is high, thereby a loss of light emitted after reflected on the anode  112  is large. The absorptance by the anode has a large influence on the organic electroluminescence device. When light-emitting efficiency is low, the amount of current required to obtain the same intensity is increased. An increase in the amount of drive current affects on the life of the device, which is a critical problem in the practical use of the organic electroluminescence device. 
         [0007]    In view of the foregoing, it is an object to provide an organic electroluminescence device capable of enhancing the reflectance of the anode so as to improve light-emitting efficiency, and a method of manufacturing the same. 
       SUMMARY 
       [0008]    An electroluminescence device according to the invention comprises one or more organic layers including a luminescent layer between an anode and a cathode, and emits light generated in the luminescent layer from the cathode, wherein the anode comprises silver (Ag) or an alloy including silver. 
         [0009]    In an embodiment, an electroluminescence device is provided. The electroluminescence device includes an anode including silver, wherein at least a portion of the anode substantially extends in a horizontal direction, parallel to a substrate and perpendicular to a thickness direction of the anode; a first layer provided over the anode; an organic layer including a luminescent layer; a cathode provided over the organic layer; and an insulating layer provided over an end portion of the anode and an end portion of the first layer, wherein at least a portion of the cathode substantially extends in the horizontal direction in a light emission region, wherein a surface of the insulating layer has a curved portion, and wherein at least a portion of the cathode within a region of the insulating layer above the curved portion extends along a first angled upward direction between the horizontal direction and the thickness direction of the anode, and wherein the cathode is separate from the anode. 
         [0010]    In an embodiment, a display device including an electroluminescence device is provided. 
         [0011]    In a first method of manufacturing an organic electroluminescence device according to the invention, the organic electroluminescence comprises one or more organic layers including a luminescent layer between an anode and a cathode and emits light generated in the luminescent layer from the cathode, and the method comprises the steps of: forming the anode comprising silver or an alloy including silver on a substrate; forming a thin film layer for hole injection made of a material with a higher work function than that of the anode on the anode in an atmosphere of an inert gas; forming the one or more organic layers including the luminescent layer on the thin film layer for hole injection; and forming the cathode on the organic layer. 
         [0012]    In a second method of manufacturing an organic electroluminescence device according to the invention, the organic electroluminescence comprises one or more organic layers including a luminescent layer between an anode and a cathode and emits light generated in the luminescent layer from the cathode, and the method comprises the steps of: forming the anode comprising silver or an alloy including silver on a substrate; forming a thin film layer for hole injection made of a material with a higher work function than that of the anode on the anode by use of an area mask with an aperture corresponding to an area where the thin film layer for hole injection is intended to be formed; forming the one or more organic layers including the luminescent layer on the thin film layer for hole injection; and forming the cathode on the organic layer. 
         [0013]    In the organic electroluminescence device according to the invention, the anode comprises silver with a highest reflectance of all of metals or an alloy including silver, so a loss of light absorption by the anode is reduced, thereby light generated in the luminescent layer can be efficiently emitted. 
         [0014]    In the first method of manufacturing an organic electroluminescence device according to the invention, after the anode comprising silver or an alloy including silver is formed on the substrate, on the anode, the thin film layer for hole injection is formed in an atmosphere of an inert gas. Therefore, thin film layer for hole injection prevents the anode from being deteriorated, and the anode can be prevented from being deteriorated during the formation of the thin film layer for hole injection. 
         [0015]    In the second method of manufacturing an organic electroluminescence device according to the invention, after the anode comprising silver or an alloy including silver is formed on the substrate, the thin film layer for hole injection is formed on the anode by use of an area mask with an aperture corresponding to an area where the thin film layer for hole injection is intended to be formed. Therefore, the thin film layer for hole injection can prevent the anode from being deteriorated, and etching is not required to form the thin film layer for hole injection, so the anode can be prevented from being deteriorated and deformed due to etching. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a sectional view of a configuration of an organic electroluminescence device according to a first embodiment of the invention; 
           [0017]      FIGS. 2A through 2C  are sectional views showing a method of manufacturing the organic electroluminescence device shown in  FIG. 1  in sequence; 
           [0018]      FIGS. 3A and 3B  are sectional views showing a modification of a method of the organic electroluminescence device according to the first embodiment in sequence; 
           [0019]      FIG. 4  is a sectional view of a configuration of an organic electroluminescence device according to a second embodiment of the invention; 
           [0020]      FIGS. 5A and 5B  are sectional views showing a method of manufacturing the organic electroluminescence device shown in  FIG. 4  in sequence; and 
           [0021]      FIG. 6  is a sectional view of a configuration of a conventional organic electroluminescence device. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Preferred embodiments of the present invention will be described in more detail below referring to the accompanying drawings. 
       First Embodiment 
       [0023]      FIG. 1  shows a sectional configuration of an organic electroluminescence device according to a first embodiment of the invention. An organic electroluminescence device  10 , which is used for an extra-thin type organic EL display or the like, comprises an anode  12 , a thin film layer for hole injection  13 , an insulating layer  14 , an organic layer  15  and a cathode  16  which are laminated in this order on a substrate  11  made of, for example, an insulating material such as glass. Further, a passivation film (not shown) is formed on the cathode  16 , and the whole device is sealed with a sealing substrate (not shown). 
         [0024]    The anode  12  has a thickness in a laminating direction (hereinafter simply referred to as thickness) of, for example, 200 nm, and comprises silver or an alloy including silver, because silver, which has highest reflectance of all metals, can reduce a loss of light absorption by the anode  12 . The anode  12  comprising silver is preferable because it can have the highest reflectance, although the anode  12  comprising an alloy of silver and other metal is more preferable, because chemical stability and processing accuracy of the anode  12  can be enhanced, and the adhesion of the anode  12  to the substrate  11  and the thin film layer for hole injection  13  can be improved. Silver has very high reactivity, low processing accuracy and low adhesion, thereby it is very difficult to handle silver. 
         [0025]    A silver content in the alloy is preferably 50% by mass or over, so that the reflectance of the anode  12  can be sufficiently enhanced. As the alloy including silver, for example, an alloy including silver, palladium (Pd) and copper (Cu) is preferable. A palladium content and a copper content in the alloy are preferably within a range, for example, from 0.3% by mass to 1% by mass, because the reflectance can be sufficiently enhanced, and the processing accuracy, the chemical stability and the adhesion can be enhanced. 
         [0026]    The thin film layer for hole injection  13  is provided to enhance efficiency of hole injection into the organic layer  15 , and comprises a material with a higher work function than that of the anode  12 . Moreover, the thin film layer for hole injection  13  has a function as a protective film which prevents silver or the alloy including silver from reacting with oxygen or a sulfur content in air, and mitigates damage to the anode  12  in a manufacturing step after forming the anode  12 . Materials of the thin film layer for hole injection  13  include, for example, a metal such as chromium, nickel (Ni), cobalt (Co), molybdenum (Mo), platinum (Pt) or silicon (Si), an alloy including at least one selected from the above metals, or an oxide of any one of the metals or the alloy, a nitride of any one of the metals or the alloy, or a transparent conductive material such as ITO. It is preferable that the thickness of the thin film layer for hole injection  13  is determined depending upon the light transmittance and electrical conductivity of the material. For example, when the thin film layer for hole injection  13  comprises an oxide or a nitride with relatively low electrical conductivity such as chromium oxide (III) (Cr 2 O 3 ), the thickness is preferably as thin as, for example, approximately 5 nm. When the thin film layer for hole injection  13  comprises a metal with high electrical conductivity and low transmittance, the thickness is preferably as thin as, for example, a few nm. On the other hand, when the thin film layer for hole injection  13  comprises ITO with high electrical conductivity and high transmittance, the thickness can be as thick as a few nm to a few tens nm. 
         [0027]    The insulating layer  14  is provided to secure the insulation between the anode  12  and the cathode  16  and accurately form a light-emitting area in the organic electroluminescence device  10  in a desired shape. The insulating layer  14  comprises an insulating material such as, for example, silicon dioxide (SiO 3 ). The insulating layer  14  has a thickness of, for example, approximately 600 nm, and in the insulating layer  14 , an aperture portion  14 A is disposed corresponding to a light-emitting area. 
         [0028]    The organic layer  15  includes a hole injection layer  15 A, a hole transport layer  15 B and a luminescent layer  15 C, all of which are made of an organic material, laminated in this order from the anode  12 . The hole injection layer  15 A and the hole transport layer  15 B are provided to enhance efficiency of hole injection into the luminescent layer  15 C. The luminescent layer  15 C emits light by current injection, and an area of the luminescent layer  15 C corresponding to the aperture portion  14 A of the insulating layer  14  emits light. 
         [0029]    The hole injection layer  15 A has a thickness of, for example, approximately 30 nm, and is made of 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA). The hole transport layer  15 B has a thickness of, for example, approximately 20 nm, and is made of bis[(N-naphthyl)-N-phenyl]benzidine (α-NPD). The luminescent layer  15 C has a thickness of, for example, approximately 50 nm, and is made of  8 -quinolinol aluminum complex (Alq). 
         [0030]    The cathode  16  includes a semi-transparent electrode  16 A having semi-transparency to light generated in the luminescent layer  15 C, and a transparent electrode  16 B having transmittance for the light generated in the luminescent layer  15 C, which are laminated in this order from the organic layer  15 . The semi-transparent electrode  16 A has a thickness of, for example, approximately 10 nm, and is made of an alloy of magnesium (Mg) and silver (MgAg alloy). The magnesium-silver alloy preferably has a magnesium-to-silver mass ratio of 9 to 1. 
         [0031]    The semi-transparent electrode  16 A is provided to reflect the light generated in the luminescent layer  15 C between the semi-transparent electrode  16 A and the anode  12 . In other words, the semi-transparent electrode  16 A and the anode  12  constitute a resonant portion in a resonator which resonates the light generated in the luminescent layer  15 C. It is preferable that such a resonator is constituted, because the light generated in the luminescent layer  15 C causes multiple interference to function as a kind of narrow-band filter, and thereby a half-value width of a spectrum of emitted light can be reduced and color purity can be improved. 
         [0032]    For that purpose, it is preferable to match a peak wavelength of the narrow-band filter and a peak wavelength of the spectrum of light desired to be emitted. In other words, assuming that a phase shift of reflected light generated in the anode  12  and the semi-transparent electrode  16 A is φ (rad), an optical distance between the anode  12  and the semi-transparent electrode  16 A is L, and the peak wavelength of the spectrum of light desired to be emitted from the cathode  16  is λ, the optical distance L preferably satisfies a mathematical formula 1, and in fact, the optical distance L is preferably selected to be a positive minimum value satisfying the mathematical formula 1. Further, in the mathematical formula 1, the units of L and λ, may be the same, for example, “nm”. (Mathematical Formula 1) 
         [0000]      2 L/λ+φ/ 2π= q  ( q  is an integer)
 
         [0033]    The transparent electrode  16 B is provided to reduce electrical resistance of the semi-transparent electrode  16 A, and is made of an electrically conductive material having sufficient translucency to the light generated in the luminescent layer  15 C. As the material of the transparent electrode  16 B, for example, a compound including indium, zinc (Zn) and oxygen is preferable, because the compound can obtain good electrical conductivity even if film formation is carried out at ambient temperature. The transparent electrode  16 B preferably has a thickness of, for example, approximately 200 nm. 
         [0034]    The organic electroluminescence device  10  can be manufactured according to the following steps, for example. 
         [0035]      FIGS. 2A through 2C  show a method of manufacturing the organic electroluminescence device  10  in sequence. At first, as shown in  FIG. 2A , the anode  12  comprising silver or an alloy including silver with the above-described thickness is formed on the substrate  11  made of the above-described material through, for example, direct current sputtering, which is carried out by the use of, for example, argon (Ar) as a sputtering gas at a pressure of, for example, 0.2 Pa and an output of, for example, 300 W. 
         [0036]    Next, as shown in  FIG. 2A , the thin film layer for hole injection  13  made of the above-described material with the above described thickness is formed on the anode  12  through, for example, high frequency sputtering. At this time, the thin film layer for hole injection  13  is preferably formed at a pressure of, for example, 0.3 Pa and an output of, for example, 10 W in an atmosphere of an inert gas using an inert gas of argon (Ar), nitrogen (N 2 ) or the like as a sputtering gas. The reactivity of silver comprised in the anode  12  is high, so when the thin film layer for hole injection  13  is formed in an atmosphere of oxygen, the anode  12  is also oxidized. Therefore, the thin film layer for hole injection  13  made of an oxide such as, for example, chromium oxide is preferably formed not in an atmosphere of oxygen using a metal target such as a chromium target but in an atmosphere of an inert gas using an oxide target such as chromium oxide. 
         [0037]    Next, as shown in  FIG. 2B , the anode  12  and the thin film layer for hole injection  13  are selectively etched through lithography by, for example, a mixed solution of nitric acid, phosphoric acid and acetic acid to be patterned in predetermined shapes. After that, as shown in  FIG. 2B , the insulating layer  14  with the above-described thickness is formed all over the substrate  11  through CVD (chemical vapor deposition), and an area of the insulating layer  14  corresponding to a light-emitting area is selectively removed through, for example, lithography to form the aperture portion  14 A. 
         [0038]    After forming the insulating layer  14 , as shown in  FIG. 2C , the hole injection layer  15 A, the hole transport layer  15 B, the luminescent layer  15 C and the transparent electrode  16 A all of which are made of the above-described materials with the above-described thicknesses are formed in order through, for example, vapor deposition. At this time, by the use of a metallic area mask  21  with an aperture  21 A corresponding to an area where the layers are intended to be formed, the layers are preferably formed corresponding to the light-emitting area, that is, the aperture portion  14 A of the insulating layer  14 . However, it is difficult to carry out vapor deposition only on the aperture portion  14 A with high accuracy, so the layers are preferably formed on the whole aperture portion  14 A and an edge of the insulating layer  14  around the aperture portion  14 A. 
         [0039]    More specifically, at first, 0.2 g each of the materials of the hole injection layer  15 A, the hole transport layer  15 B and the luminescent layer  15 C are filled in, for example, respective boats for resistance heating, and the boats are mounted on predetermined electrodes of a vacuum deposition apparatus (not shown). For example, regarding magnesium and silver forming the semi-transparent electrode  16 A, 0.1 g of magnesium and 0.4 g of silver are filled in respective boats for resistance heating, and the boats are mounted on predetermined electrodes of the vacuum deposition apparatus (not shown). Further, as a cathode of the vacuum deposition apparatus (not shown), for example, an alloy of magnesium and silver is used. Next, after an pressure of an atmosphere in the vacuum deposition apparatus (not shown) is reduced to, for example, 1.0×10 −4  Pa, a voltage is applied to each boat for resistance heating to heat in order, thereby the hole injection layer  15 A, the hole transport layer  15 B, the luminescent layer  15 C and the semi-transparent electrode  16 A are deposited in order. When the semi-transparent electrode  16 A is deposited, magnesium and silver are deposited together, and a growth rate ratio of magnesium to silver is set at, for example, 9:1. 
         [0040]    Finally, the transparent electrode  16 B is formed on the semi-transparent electrode  16 A by the use of the same metallic mask  21  through, for example, direct current sputtering, which is carried out by the use of a mixed gas of argon and oxygen (a volume ratio of Ar:O 2 =1000:5) as a sputtering gas at a pressure of, for example, 0.3 Pa, and an output of, for example, 40 W. Thereby, the organic electroluminescence device  10  shown in  FIG. 1  is formed. 
         [0041]    In the organic electroluminescence device  10 , when a predetermined voltage is applied between the anode  12  and the cathode  16 , a current is injected into the luminescent layer  15 C to re-bond holes and electrons, thereby light is emitted mainly from an interface on a side of the luminescent layer  15 C. The light is multiply reflected between the anode  12  and the semi-transparent electrode  16 A, and then passes through the cathode  16  to be emitted. In the embodiment, the anode  12  comprises silver or an alloy including silver, so reflectance of the anode  12  is enhanced. Thereby, the light generated in the luminescent layer  15 C is efficiently emitted. 
         [0042]    Thus, according to the embodiment, the anode  12  comprises silver or an alloy including silver, so the reflectance of the anode  12  can be enhanced, and a loss of light absorption by the anode  12  can be reduced. Thereby, efficiency of emitting the light generated in the luminescent layer  15 C can be improved. 
         [0043]    More specifically, the anode  12  comprising an alloy including silver, palladium and copper allows improving the chemical stability, the processing accuracy and the adhesion. Further, when the silver content in the alloy is 50% by mass or over, the reflectance can be sufficiently enhanced, and the chemical stability, the processing accuracy and the adhesion can be improved. 
         [0044]    Moreover, when the thin film layer for hole injection  13  made of a material with a higher work function than that of the anode  12  is disposed between the anode  12  and the organic layer  15 , the efficiency of hole injection into the organic layer  15  can be further enhanced. Further, silver or an alloy including silver comprised in the anode  12  can be prevented from reacting with oxygen or a sulfur content in air, and damage to the anode  12  in a manufacturing process after forming the anode  12  can be mitigated. 
         [0045]    In addition, in the case where the thin film layer for hole injection  13  is formed in an atmosphere of an inert gas, even if the anode  12  comprises silver with high reactivity or an alloy including silver, the anode  12  can be prevented from being deteriorated such as oxidation during the formation of the thin film layer for hole injection  13 . Thus, target properties of the anode  12  can be obtained, and thereby the organic electroluminescence device  10  according to the embodiment can be easily obtained. 
       MODIFICATION 
       [0046]      FIGS. 3A and 3B  show a modification of a method of manufacturing the organic electroluminescence device  10  according to the first embodiment. In the modification, the thin film layer for hole injection  13  is formed by the use of an area mask  22 , thereby the thin film layer for hole injection  13  is not required to be patterned through lithography or the like. 
         [0047]    At first, as shown in  FIG. 3A , as described above, the anode  12  is formed on the substrate  11 , and then is patterned. Next, as shown in  FIG. 3B , through, for example, high frequency sputtering, by the use of the area mask  22  with an aperture  22 A corresponding to an area where the thin film layer for hole injection  13  is intended to be formed, the thin film layer for hole injection  13  is formed only on desired part, that is, on the patterned anode  12 . The conditions of film formation such as the sputtering gas and so on are the same as those in the first embodiment. Then, as in the case of the first embodiment, the insulating layer  14 , the organic layer  15  and the cathode  16  are formed. 
         [0048]    Thus, according to the modification, the thin film layer for hole injection  13  is formed by the use of the area mask  22 , it is not required to pattern the thin film layer for hole injection  13  through lithography or the like. Therefore, even if the anode  12  comprises silver with high reactivity or an alloy including silver, the anode  12  can be prevented from being etched too much during etching to pattern the thin film layer for hole injection  13 , or being deteriorated. Thereby, the patterning accuracy of the anode  12  can be improved, and target properties of the anode  12  can be obtained. In other words, the organic electroluminescence device according to the embodiment can be easily obtained. 
       Second Embodiment 
       [0049]      FIG. 4  shows a sectional configuration of an organic electroluminescence device according to a second embodiment of the invention. An organic electroluminescence device  30  is equivalent to the organic electroluminescence device  10  described in the first embodiment, except that the thin film layer for hole injection  13  is disposed on the anode  12  and the insulating layer  14 . Therefore, like components are denoted by like numerals as of the first embodiment and will not be further explained. 
         [0050]      FIGS. 5A and 5B  show a method of manufacturing the organic electroluminescence device  30  in sequence. At first, as shown in  FIG. 5A , as in the case of the first embodiment, on the substrate  11 , the anode  12  is formed, and then is patterned in a predetermined shape through, for example, lithography. Next, as shown in  FIG. 5A , as in the case of the first embodiment, the insulating layer  14  is formed all over the anode  12  and the substrate  11 , and the aperture portion  14 A is formed. Next, as shown in  FIG. 5B , by the use of an area mask  23  with an aperture  23 A corresponding to an area where the thin film layer for hole injection  13  is intended to be formed, as in the case of the first embodiment, the thin film layer for hole injection  13  is formed. At this time, the thin film layer for hole injection  13  is laid on the whole aperture portion  14 A and an edge of the insulating layer  14  around the aperture portion  14 A. After that, by the use of the same area mask  23 , as in the case of the first embodiment, the organic layer  15  and the cathode  16  are formed. 
         [0051]    Thus, according to the embodiment, the thin film layer for hole injection  13  is formed by the use of the area mask  23 , so the embodiment provides the effects equal to those of the above modification. 
         [0052]    Moreover, specific examples of the invention will be described below. 
         [0053]    In a manner similar to the first embodiment, the modification of the first embodiment and the second embodiment, the organic electroluminescence devices were manufactured. At that time, the anode  12  comprised an alloy including 98% by mass of silver, 1% by mass of palladium and 1% by mass of copper, and the thin film layer for hole injection  13  comprised chromium oxide (III) (Cr 2 O 3 ). When the light-emitting efficiencies of the organic electroluminescence devices were determined at an intensity of 1000 (cd/m 2 ), a voltage of 6.47 (V) and a current of 0.341 (mA), all of them were approximately 11.7 (cd/A). 
         [0054]    As a comparative example with respect to the examples, in a manner similar to the examples, an organic electroluminescence device was formed. The organic electroluminescence device was equivalent to the examples except that like a conventional one, the anode comprised chromium, and the thin film layer for hole injection was not formed. The light-emitting efficiency of the organic electroluminescence device of the comparative example determined at an intensity of 1000 (cd/m 2 ), a voltage of 7.16 (V) and a current of 0.69 (mA) was 5.86 (cd/A). 
         [0055]    Thus, the examples could obtain approximately twice higher light-emitting efficiency than that of the comparative example. In other words, it turned out that the anode  12  comprising silver could enhance the reflectance thereof, thereby resulting in improved properties. 
         [0056]    The invention is described referring to the embodiments. However, the invention is not limited to the above embodiment, but is applicable to various modifications. For example, the invention is not limited to the materials and thickness of each layer or the method and conditions of film formation described in the above embodiments, but any other materials and thickness or any other method and conditions of film formation may be applicable. 
         [0057]    In the above embodiments, the configurations of the organic electroluminescence device are described in detail, but all layers such as the thin film layer for hole injection  13 , the insulating layer  14  or the transparent electrode  16 B may not be necessarily comprised, and any other layer may be further comprised. In addition, although the invention can be applied to the case where the semi-transparent electrode  16 A is not comprised, an object of the invention is to enhance the reflectance of the anode  12 , so the case where the semi-transparent electrode  16 A and the anode  12  constitute a resonant portion in a resonator can obtain a higher effect. 
         [0058]    As described above, in the organic electroluminescence device according to the invention, the anode comprises silver or an alloy including silver, so the reflectance of the anode can be enhanced, and a loss of light absorption by the anode can be reduced. Thereby, the efficiency of emitting light generated in the luminescent layer can be improved. 
         [0059]    Specifically, in the organic electroluminescence device according to the invention, the anode comprises an alloy including silver, palladium and copper, so the chemical stability, the processing accuracy and the adhesion of the anode can be improved, thereby resulting in further improved properties. 
         [0060]    Moreover, in the organic electroluminescence device according to the invention, the silver content in the anode is 50% by mass or over, so while the reflectance can be sufficiently enhanced, the chemical stability, the processing accuracy and the adhesion can be improved, thereby resulting in further improved properties. 
         [0061]    Further, in the organic electroluminescence device according to the invention, the thin film layer for hole injection with a higher work function than that of the anode is disposed between the anode and the organic layer, so the efficiency of hole injection into the organic layer can be enhanced. Further, silver or an alloy including silver comprised in the anode can be prevented from reacting with oxygen or a sulfur content in air, and can mitigate damage to the anode in a manufacturing step after forming the anode. 
         [0062]    In a method of manufacturing the organic electroluminescence device according to the invention, the thin film layer for hole injection is formed in an atmosphere of an inert gas, so even if the anode comprises silver with higher reactivity or an alloy including silver, the anode can be prevented from being deteriorated such as oxidation during the formation of the thin film layer for hole injection. Therefore, target properties of the anode can be obtained, and thereby the organic electroluminescence device according to the invention can be easily obtained. 
         [0063]    Moreover, in a method of manufacturing organic electroluminescence device according to the invention, the thin film layer for hole injection is formed by the use of the area mask, so the thin film layer for hole injection is not required to be patterned through lithography or the like. Therefore, even if the anode comprises silver with high reactivity or an alloy including silver, the anode can be prevented from being etched too much during etching to pattern the thin film layer for hole injection or from being deteriorated. Thereby, while the patterning accuracy of the anode can be improved, target properties of the anode can be obtained. In other words, the organic electroluminescence device according to the invention can be easily obtained. 
         [0064]    Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.