JP2004152786A - Photoelectric conversion device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the structure of a photoelectric conversion device in which damage to a semiconductor layer is lessened in a manufacturing method and limits on an electrode material and a method for manufacturing an electrode structure are small, and to provide its manufacturing method. <P>SOLUTION: In the photoelectric conversion device, two electrodes laid in layers through an insulating film are manufactured previously, and a semiconductor layer is formed after the electrodes are manufactured and shaped. The electrode structure comprises a first electrode, an insulating film laid in layer on a first electrode, a second electrode laid in layer on the insulating film and not touching the first electrode directly, and a semiconductor layer touching both the first and second electrodes. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a photoelectric conversion element used for a solar cell, an imaging device, a sensor, and the like.
[0002]
[Prior art]
The basic structure of a photoelectric conversion element has a sandwich structure in which a semiconductor is sandwiched between two electrodes. A step of forming a first electrode on a substrate and a step of forming a semiconductor layer on the first electrode The photoelectric conversion element has been manufactured by using a manufacturing method including a step and a step of forming a second electrode on a semiconductor layer. In this method, since the second electrode has to be formed on the semiconductor layer by a method such as vacuum deposition or screen printing, the semiconductor or its interface may be damaged during the formation of the second electrode. .
[0003]
In addition, it is widely and generally practiced to pattern and manufacture the second electrode in order to increase light use efficiency. This is for minimizing the obstruction of light incident on the semiconductor by the electrode on the light incident side (referred to as shadow loss). As a technique for avoiding shadow loss, Patent Literature 1 below has both a positive electrode and a negative electrode in contact with a semiconductor layer on a surface opposite to a light incident surface. A photoelectric conversion element having an embedded structure is disclosed. In this structure, since both the positive and negative electrodes are on the opposite side to the light incident side, there is no shadow loss.
[0004]
In recent years, as a technique for using an organic material for a semiconductor layer, Non-Patent Document 1 listed below discloses a technique using planar joining of an electron-accepting material and an electron-donating material. Has suggested a technique using a heterobulk junction between an electron-accepting material, fullerene and a derivative thereof, and an electron-donating material.The structure based on this document employs a sandwich structure in which a semiconductor is sandwiched between two electrodes. ing.
[0005]
[Patent Document 1]
JP-A-2001-44463
[0006]
[Patent Document 2]
Japanese Patent Publication No. Hei 8-500701
[0007]
[Non-patent document 1]
CW Tang, "Two-layer organic photovoltaic cell", Applied Physics Letters, American Institute of Physics, 1986, 48, p. 183-185
[0008]
[Problems to be solved by the invention]
As described above, in the structure of the conventional photoelectric conversion element, since the vacuum deposition or the screen electrode must be formed on the semiconductor layer, the semiconductor or its interface may be damaged when the electrode is formed. In addition, it is widely and generally practiced to pattern and manufacture the second electrode in order to increase light use efficiency. However, when the second electrode is processed into a certain pattern, the semiconductor or its interface may be damaged. There was a limit to the processing method because it could be damaged.
[0009]
Patent Literature 1 discloses a structure in which both a positive electrode and a negative electrode in contact with a semiconductor layer are provided on a surface opposite to a light incident surface, and a recess is provided in the semiconductor layer and one electrode is embedded therein, and a manufacturing method thereof. However, in the disclosed manufacturing method, a semiconductor or a semiconductor / electrode interface may be damaged because a recess must be formed in a semiconductor layer and an electrode must be formed therein. In actual manufacturing, the manufacturing process is complicated, for example, it is necessary to form a structure in which an electrode is embedded in a concave portion of a semiconductor, and then peel and transfer the structure to another substrate. Low cost and high cost.
[0010]
In particular, in a photoelectric conversion element using an organic material, an organic semiconductor generally has lower resistance to heat, light, chemical substances, and the like during electrode formation and processing than an inorganic material. This is one of the causes of the low conversion efficiency of the used photoelectric conversion element.
[0011]
An object of the present invention is to solve the problems of the above technology, and to provide a structure of a photoelectric conversion element which causes less damage to a semiconductor layer in a manufacturing process and has less restrictions on an electrode material and an electrode structure manufacturing method, and a method for manufacturing the same. With the goal.
[0012]
[Means for Solving the Problems]
In a photoelectric conversion element of the present invention made to solve the above-described problem, a first electrode, an insulating layer stacked on the first electrode, and an insulating layer stacked on the insulating layer, By employing a structure including a second electrode that is not in contact with an electrode and a semiconductor layer that is in contact with both the first electrode and the second electrode, two electrodes stacked with an insulating film interposed therebetween can be used. It is possible to form the semiconductor layer in advance after preparing the electrode and forming the semiconductor layer in a step after the processing of the shape of the electrode. Damage can now be avoided.
[0013]
Charges (electrons, holes) or electron-hole pairs generated by light incident on the semiconductor layer are generated between the first electrode and the second electrode by an externally applied electric field, an electric field inside the semiconductor layer, or By the electric field generated in the vicinity of the interface between the semiconductor layer and the electrode, the electrons or holes are collected by the first electrode and the second electrode, respectively, and extracted outside. Here, the electric field inside the semiconductor layer is formed by contact of materials having different electrical properties such as a pn junction formed in the semiconductor layer. The electric field generated near the interface between the semiconductor layer and the electrode is formed by, for example, a Schottky junction generated by contact between the metal and the semiconductor.
[0014]
A light reflection layer may be provided on the surface of the semiconductor layer opposite to the electrode. When light is incident from the electrode side of the semiconductor layer by providing the reflective layer, light penetrating the semiconductor layer is reflected by the reflective layer and reenters the semiconductor layer, so that light use efficiency can be increased. .
[0015]
The first electrode may be formed of a transparent conductive material. When light is incident from the electrode side of the semiconductor layer by making the first electrode transparent, incident light can reach the semiconductor layer without being blocked.
[0016]
When light is incident from the electrode side of the semiconductor layer by forming the first electrode, the second electrode, and the insulating layer with a transparent material, the light is not hindered by the second electrode and the insulating layer. Can reach the semiconductor layer.
[0017]
The semiconductor layer may be formed of a photoconductive material. Since the electrical conductivity of the semiconductor layer can be changed according to the amount of light incident on the semiconductor layer, by applying an externally applied electric field between the first electrode and the second electrode, It can be applied to a device for detecting such a change in conductivity, for example, an optical sensor, an imager, and the like.
[0018]
The semiconductor layer may be composed of a region made of an electron accepting material (acceptor) and a region made of an electron donating material (donor). Charges or electron-hole pairs generated by light incident on the semiconductor layer are converted into electrons or holes due to an internal electric field generated at the interface between the region formed of the electron-accepting material (acceptor) and the electron-donating material (donor). Each is collected by the first electrode and the second electrode and taken out. The photovoltaic power generated in this way can be applied to, for example, a solar cell, an optical sensor, an imager, and the like.
[0019]
The semiconductor layer may be formed using a material that forms a Schottky junction with the first electrode or the second electrode. Charges or electron-hole pairs generated by light incident on the semiconductor layer are collected as electrons or holes by the first electrode and the second electrode as electrons or holes, respectively, by an electric field generated by a Schottky junction between the semiconductor and the electrode. Is taken out. The photovoltaic power generated in this way can be applied to, for example, a solar cell, an optical sensor, an imager, and the like.
[0020]
The semiconductor layer, the electrode, and the insulating layer may be made of an organic material. By using an organic material, a film can be formed and processed basically by a normal temperature process, so that it can be manufactured with reduced energy consumption. If an organic material is used, the element can be manufactured by a simple and low-cost process such as coating and printing. In addition, since organic materials generally have high flexibility, a flexible element can be manufactured.
[0021]
The above-described photoelectric conversion element according to the present invention is manufactured by the following manufacturing method. That is, a step of forming a first electrode, a step of forming an insulating layer on the first electrode, a step of forming a second electrode on the insulating layer, and exposing the first electrode And a step of forming a semiconductor layer in contact with both the first electrode and the second electrode, wherein the step of forming a semiconductor layer in the step, This is the last step, and is performed so as to be in contact with the first electrode and the second electrode. By setting the step of forming a semiconductor layer in the above steps as the last step, it is possible to eliminate damage to the semiconductor due to an electrode forming step on the semiconductor layer, processing for pattern formation, and the like. it can.
[0022]
The first electrode, the insulating layer, the second electrode, and the semiconductor layer may be formed by an inkjet printing method. In the case of an organic material, a solution dissolved in an appropriate solvent is used, and in the case of an inorganic material, for example, fine particles can be formed, or fine particles can be dispersed in a liquid, whereby the ink can be handled like ink. In the inkjet printing method, a thin film having a desired pattern can be formed without a separate processing step. In addition, since it is a coating process, the process is very simple, the reliability is enhanced, and the cost is easily reduced.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the photoelectric conversion element of the present invention will be described.
[0024]
This embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing a photoelectric conversion element of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG.
[0025]
1 is an example of the photoelectric conversion element of the present invention, in which a first electrode 2 and a second electrode 4 are laminated with an insulating layer 3 interposed therebetween, and a semiconductor layer 5 is formed of the first layer. And the second electrode 4. Here, as long as the semiconductor layer 5 has a structure in which light reaches the semiconductor layer, the pattern shape of the electrode and the insulating layer is not particularly limited. Although the pattern shape of the electrode is shown in FIG. 1 as a shape having a comb-like stripe on one side, it is not limited to this shape. For example, it may be a shape in which stripes are formed on both sides in the form of comb teeth, or a shape in which a plurality of comb-shaped stripes are interchanged. Further, the shape may be spread in a mesh shape.
[0026]
Further, the pattern shapes of the electrodes and the insulating layers will be described with reference to FIGS. The first electrode 2 formed on the substrate 1 is formed continuously over substantially the entire surface of the substrate 1. The insulating layer 3 and the second electrode 4 thereon have substantially the same comb tooth shape. The semiconductor layer 5 substantially embeds the exposed portions of the comb-shaped insulating layer 3, the second electrode 4, and the first electrode 2. However, as shown in FIG. 3, a part of the first electrode 2 and a part of the second electrode 4 are exposed so that they can be electrically connected to the outside.
[0027]
Next, the pattern of the electrode and the insulating layer will be exemplarily described with reference to FIG. FIGS. 4A to 4D correspond to cross-sectional views taken along line II-II in FIG. 1 and illustrating patterns of electrodes and insulating layers in the photoelectric conversion element of the present invention. The first electrode 42a may be patterned, as in the example of FIG. 4A, or the first electrode 42b, the insulating layer 43b, and the second electrode 42, as in the example of FIG. 44b may have different widths. Further, as in the example of FIG. 4C, the semiconductor layer 45c can be formed into a shape along the irregularities due to the electrode pattern. Furthermore, as in the example of FIG. 4D, the first electrode 42d may not be in a position overlapping with the second electrode 44d when viewed from the normal direction of the plane of the semiconductor layer 45d. Further, in FIGS. 1 to 5, the ends of the electrodes and the insulating layers are drawn in a vertically steep shape, but may be tapered.
[0028]
Further, the pattern of the electrode and the insulating layer will be exemplarily described with reference to FIG. FIGS. 5A to 5C correspond to cross-sectional views taken along line III-III in FIG. 1 showing patterns of electrodes and insulating layers in the photoelectric conversion element of the present invention. As shown in the example of FIG. 5A, a first electrode 52a having a shape such that a part of the substrate 51a is exposed is formed on the substrate 51a, and the first electrode 52a is formed on the first electrode 52a. An insulating layer 53a is formed so as to cover the second electrode 52a, a second electrode 54a is formed thereon, and a semiconductor layer 55a is formed thereon from a shape such that a part of the second electrode 54a is exposed. May be. Also, as in the example of FIG. 5B, a first electrode 52b is formed on the substrate 51b in such a shape that a part of the substrate 51b is exposed, and the first electrode 52b is formed on the first electrode 52b. An insulating layer 53b having a shape exposing a part of the substrate 51b is formed so as to cover the first electrode 52b, a second electrode 54b is formed thereon, and a semiconductor layer 55b on the second electrode 54b is formed. The second electrode 54b may be formed in a shape such that a part of the second electrode 54b is exposed. As described above, by forming a structure in which a part of the first electrode 52b and the second electrode 54b is exposed, the exposed portion can be used for wiring between elements or outside. After the first electrode 52c, the insulating layer 53c, and the second electrode 54c are formed by lamination as shown in FIG. 5C, a pattern may be formed by a technique such as etching as needed. Then, a contact portion to the electrode may be formed.
[0029]
<Semiconductor layer>
Materials constituting the semiconductor layer include Si, III-V group (mainly GaAs type, InP, GaAlAs, etc.), II-VI group (CdS / CdTe type, Cu ₂ S, ZnS, ZnSe, etc.), I-III-VI groups, organic semiconductors, and the like, but are not particularly limited thereto. In the case of an organic semiconductor, the resistance to heat, light, and chemical substances during electrode formation and processing is generally lower than that of an inorganic material, and thus the semiconductor is easily damaged. In the present invention, the semiconductor layer is formed last. Therefore, it is effective in that such an organic material can be used without being damaged by re-forming such as electrode formation.
[0030]
As the organic material constituting the semiconductor layer, any of a material having an electron accepting function and a material having an electron donating function can be used. For example, the following materials can be used, but are not particularly limited.
[0031]
(I) Electron accepting material
Examples of the electron-accepting material include oligomers and polymers having a skeleton of pyridine and its derivatives, oligomers and polymers having a skeleton of quinoline and its derivatives, ladder polymers of benzophenanthrolines and their derivatives, and cyano-polyphenylenevinylene. Low molecules such as molecules, fluorinated metal-free phthalocyanines, fluorinated metal phthalocyanines and derivatives thereof, perylene and derivatives thereof (such as PTCDA and PTCDI), naphthalene derivatives (such as NTCDA and NTCDI), and bathocuproine and derivatives thereof can be used.
[0032]
(Ii) electron donating material
Examples of the electron donating material include oligomers and polymers having a skeleton of thiophene and its derivatives, oligomers and polymers having a skeleton of phenylene-vinylene and its derivatives, oligomers and polymers having a skeleton of fluorene and its derivatives, and benzofurans and derivatives thereof. Oligomers and polymers having a skeleton, oligomers and polymers having a thienylene-vinylene and its derivatives in the skeleton, oligomers and polymers having an aromatic tertiary amine such as triphenylamine and its derivatives in the skeleton, carbazole and derivatives thereof in the skeleton Oligomers and polymers having a skeleton of vinylcarbazole and its derivatives, oligomers and polymers having a skeleton of pyrrole and its derivatives, oligomers and polymers having a skeleton of acetylene and its derivatives, Polymers such as oligomers and polymers having a skeleton of sothianaphen and its derivatives, oligomers and polymers having a skeleton of heptadiene and its derivatives, metal-free phthalocyanines, metal phthalocyanines and their derivatives, diamines, phenyldiamines and their derivatives , Acenes such as pentacene and derivatives thereof, porphyrin, tetramethylporphyrin, tetraphenylporphyrin, tetrabenzporphyrin, monoazotetrabenzporphyrin, diazotetrabenzporfin, triazotetrabenzporphyrin, octaethylporphyrin, octaalkylthioporphyrazine, octa Metal-free porphyrins such as alkylaminoporphyrazine, hemiporphyrazine, chlorophyll, etc. Conductor, cyanine dyes, merocyanine dyes, squarylium dyes, quinacridone dyes, azo dyes, anthraquinone, benzoquinone, small molecules such as quinone-based dyes naphthoquinone may be utilized. The central metals of metal phthalocyanine and metal porphyrin include metals such as magnesium, zinc, copper, silver, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, platinum, lead, and metal oxides. Metal halides are used.
[0033]
As the semiconductor layer in the present invention, the above-mentioned materials can be used alone, but it is also possible to use a material in which the above-mentioned materials are dispersed and mixed in an appropriate binder material. In addition, a material in which the above-described low molecule is incorporated in the main chain or the side chain of an appropriate polymer may be used. Examples of the binder material or the main chain polymer include, for example, polycarbonate resin, polyvinyl acetal resin, polyester resin, modified ether type polyester resin, polyarylate resin, phenoxy resin, polyvinyl chloride resin, polyvinyl acetate resin, and poly (vinyl acetate). Vinylidene chloride resin Polystyrene resin, acrylic resin, methacrylic resin, cellulose resin, urea resin, polyurethane resin, silicone resin, epoxy resin, polyamide resin, polyacrylamide resin, polyvinyl alcohol resin, etc., and copolymers thereof, or polyvinyl carbazole And a photoconductive polymer such as polysilane.
[0034]
When the photoelectric conversion device of the present invention is used for a photovoltaic device such as a solar cell, an aggregate of the electron accepting material and the fine region of the electron donating material is used as a semiconductor layer. May be used. The generation of a photovoltaic force by an aggregate of fine regions of an electron-accepting material and an electron-donating material sandwiched between a pair of electrodes is described in, for example, Solid State Communications Vol. 249 and Nature Vol. 376, p. 498. As a method for producing an aggregate of fine regions composed of two kinds of materials, the above-mentioned electron accepting material and the above-mentioned electron donating material, for example, there are various methods described below.
(1) Two kinds of polymer materials are mixed and dissolved or dispersed in a solvent, and the mixed liquid is applied to a substrate having an electrode formed on a surface thereof, dried, and then heated to reduce a phase separation phenomenon. This forms a fine bonded structure of the two materials.
(2) A polymer material and a crystalline low-molecular material are mixed and dissolved or dispersed in a solvent, and the mixed liquid is applied to a substrate having an electrode formed on the surface, and the crystalline low molecules are aggregated. By microcrystallization, a fine junction structure of two materials in which low molecular microcrystals are dispersed in a high molecular material is formed.
(3) A suspension in which one or both of the two materials are formed into a fine aggregate state such as micelles in a solvent is applied on a substrate, and the solvent is evaporated to form a fine particle of the two materials. To form a simple joint structure.
(4) It is formed by utilizing a phase separation phenomenon of a block copolymer in which two kinds of polymers are bonded at one end.
(5) The surface of the substrate is in a surface state having an affinity for one of the two materials, and the surface of the substrate has a desired pattern (for example, a mesh shape) formed thereon, or And applying a mixed solution of the two materials on the substrate so that the surface of the substrate has a desired pattern and has a surface state compatible with the two materials. With this, a fine junction structure of two kinds of materials is formed by affinity with the surface.
(6) A protruding structure made of one of the two materials is formed on the surface of the substrate, and the other material in the form of a gas, a solution, or a molten liquid is supplied thereon. By forming a film so as to enclose the materials, a fine bonded structure of the two materials is formed.
(7) A hole-like structure made of one of the two materials is formed on the surface of the substrate, and the other gas, solution, or liquid material is supplied thereon, and the hole-like structure is formed. By forming a film so as to fill the structure, a fine junction structure of two kinds of materials is formed.
(8) Fine particles of each of the two materials are supplied onto the same substrate surface to form a fine bonded structure of the two materials.
(9) A solution in which materials that are both crystalline but have no compatibility are applied to a substrate and crystallized to form a fine bonded structure in which microcrystals of two materials are mixed.
[0035]
<Substrate>
The material and thickness of the substrate in the present invention are not particularly limited as long as the first electrode can be manufactured and can be stably held. For example, metals and alloys such as stainless steel, glass, resin, paper, cloth and the like can be mentioned. When light is incident from the substrate side, a material having predetermined transparency in a wavelength range required for the device is used.
[0036]
<Materials of first and second electrodes>
As the material of the first and second electrodes, metals such as gold, platinum, and aluminum, alloys, and the like are used. As the transparent electrodes, for example, indium tin oxide (ITO), fluorine-doped tin oxide, Metal oxides such as zinc oxide and tin oxide are used. A conductive polymer such as polyacetylene, polypyrrole, or polythiazyl may be used. The electrode material is selected depending on the electrical properties (such as ohmic properties and Schottky properties) with the semiconductor layer in addition to the transparency.
[0037]
In the case where the photoelectric conversion element of the present invention is used for a solar cell or the like, when a transparent conductive film is used as the material of the first and second electrodes, the work function on the cathode side is usually smaller than that on the anode side. There is a need to. The conductive metal oxide having a small work function is, for example, a metal having a small work function such as aluminum (Al), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), lithium (Li) (that is, a metal having a small work function). 4.3 eV or less metal) or aluminum oxide (Al ₂ O ₃ ), A small amount of an oxide such as magnesium oxide (MgO) or barium oxide (BaO) is added as a dopant to a transparent conductive film such as ITO or ZnO.
[0038]
<Insulating layer>
As the material of the insulating layer, in addition to inorganic materials such as a silicon oxide film, a silicon nitride film, and a mixed film thereof, for example, a polycarbonate resin, a polyvinyl acetal resin, a polyester resin, a modified ether-type polyester resin, a polyarylate resin, Phenoxy resin, polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin polystyrene resin, acrylic resin, methacrylic resin, cellulose resin, urea resin, polyurethane resin, silicone resin, epoxy resin, polyamide resin, polyacrylamide resin, polyvinyl alcohol Organic materials such as resins and copolymers thereof are used.
[0039]
Next, an embodiment in which the reflective layer 66 is further provided in the above-described photoelectric conversion element of the present invention will be described with reference to FIG. FIG. 6 is a perspective view showing the structure of the photoelectric conversion element in the case where the reflection layer 66 is formed on the structure of FIG. Of the incident light P from the side of the first electrode 62 of the semiconductor layer 65, the light transmitted through the semiconductor layer is reflected by the reflection layer 66, reenters the semiconductor layer 65, is absorbed by the semiconductor layer, and is absorbed by the semiconductor layer. Generates holes or electron-hole pairs (excitons). Also in the structure of FIG. 6, the shapes of the first electrode, the insulating layer, the second electrode, and the semiconductor layer may be shapes as shown in FIGS.
[0040]
<Reflective layer>
The material of the reflective layer is not particularly limited as long as it is a material that efficiently reflects light. For example, metals such as gold, platinum, and aluminum, alloys, and the like are used. The formation method is not particularly limited, either. For example, an evaporation method, a sputtering method, a CVD method, screen printing, or the like is used. When the reflective layer is formed, the semiconductor layer may be slightly damaged depending on the method, but is not as sensitive to the damage as the electrode interface.
[0041]
As described above, after forming the photoelectric conversion element shown in FIG. 1 or FIG. 6, a coating layer may be formed for passivation. The coating layer is desirably formed so as to cover at least the entire semiconductor layer. As a material of the coating layer, for example, an inorganic material such as a curable resin by light or heat, a silicon oxide film, a silicon nitride film, and a mixed film thereof, and an inorganic hardener such as a silicon hard coat are used. You.
[0042]
In the present invention, in order to minimize contamination, deterioration of materials, and the like, it is desirable that the material be delivered between the above-mentioned respective manufacturing steps through a space filled with a vacuum or an inert gas.
[0043]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but is not limited thereto.
[0044]
(Example 1)
The structure of the photoelectric conversion element according to the present invention based on FIG. 1 can be manufactured, for example, as follows.
[0045]
On a glass plate as the substrate 1, an ITO film having a thickness of about 80 nm was formed by a known method such as a sputtering method to obtain a first electrode 2. Next, an insulating layer 3 of silicon oxide having a thickness of about 300 nm was formed by a plasma CVD method at a temperature of 450 ° C. using silane gas and oxygen gas. The insulating layer 3 was patterned by photolithography and etching. A second electrode was formed on the patterned insulating layer 3 by depositing gold having a thickness of about 200 nm through a metal mask having a hole formed in a predetermined shape. On top of this, a mask is formed so that a part of the first electrode 2 and a part of the second electrode 4 are exposed as shown in FIG. A hydride (NTCDA) was deposited. Through the above steps, a photoelectric conversion element based on the structure in FIG. 1 was formed.
[0046]
(Example 2)
In the photoelectric conversion device based on the structure shown in FIG. 1, a method in which the semiconductor layer 5 is composed of a region made of an electron accepting material (acceptor) and a region made of an electron donating material (donor) to form a photovoltaic device Can be performed, for example, as follows, but the steps up to the step of forming the first electrode 2 are as described in the first embodiment.
[0047]
Next, an insulating film of silicon oxide of about 300 nm is formed by a plasma CVD method at a temperature of about 450 ° C. using silane gas and oxygen gas, and an Al film of about 200 nm is deposited on the insulating film. did. Next, a resist pattern having a desired shape was formed on the Al film, and the Al film was patterned by photolithography and reactive ion etching (RIE) to form a second electrode 4. Further, using the Al film (second electrode 4) from which the resist pattern was removed as a mask, the insulating film was patterned by RIE to form an insulating layer 3. On top of this, a mask is formed so that a part of the first electrode 2 and a part of the second electrode 4 are exposed as shown in FIG. ₆₀ ) And a polyphenylenevinylene (PPV) derivative dispersed in chloroform at a weight ratio of 4: 1 were applied by spin coating and dried to form a film of about 800 nm. Through the above steps, a photovoltaic element based on the structure of FIG. 1 was formed.
[0048]
According to the manufacturing method described in the present embodiment, since the alignment between the pattern of the insulating layer 3 and the pattern of the second electrode 4 as in the first embodiment is not required, the process is simplified.
[0049]
(Example 3)
In the photoelectric conversion element based on the structure shown in FIG. 1, a method of forming a photovoltaic element by forming a Schottky junction with the semiconductor layer 5 with respect to an electrode can be performed, for example, as follows. The steps up to the step of forming the layer 3 are as described in the first embodiment.
[0050]
Next, on the patterned insulating layer, Al having a thickness of about 200 nm is deposited through a metal mask having a hole formed in a predetermined shape to form a second electrode 5. A pentacene (Pentacene) thin film having a thickness of about 700 nm is formed on this by masking a part of the first electrode 2 and a part of the second electrode 4 as shown in FIG. ^-7 It was formed by an evaporation method in a torr order vacuum. Through the above steps, a photovoltaic element based on the structure of FIG. 1 was formed.
[0051]
(Example 4)
In the photoelectric conversion element based on the structure in FIG. 6, the reflective layer 66 is formed, for example, by forming an Al film having a thickness of about 300 nm on the pentacene surface of the photoelectric conversion element manufactured according to the third embodiment. ^-7 It was formed in a torr order vacuum using an evaporation method.
[0052]
【The invention's effect】
According to the present invention, it is possible to manufacture a photoelectric conversion element with less damage to a semiconductor layer and less restrictions on an electrode material and an electrode structure manufacturing method. As a result, an organic material that is difficult to use in a conventional method is also used. And a high-performance photoelectric conversion element can be provided. Further, by using such an organic material, a process for forming a structure according to the present invention can be simplified and reduced in cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a photoelectric conversion element according to the present invention.
FIG. 2 is a cross-sectional view of the photoelectric conversion element shown in FIG. 1, taken along line II-II.
FIG. 3 is a cross-sectional view of the photoelectric conversion element shown in FIG. 1, taken along line III-III.
FIGS. 4A to 4D are cross-sectional views showing another example corresponding to a cross section taken along line II-II in the photoelectric conversion element based on FIG.
5A to 5C are cross-sectional views showing another example corresponding to a cross section along line III-III in the photoelectric conversion element based on FIG. 1;
FIG. 6 is a perspective view showing another example of the photoelectric conversion element according to the present invention.
[Explanation of symbols]
1, 41a, 41b, 41c, 41d, 51a, 51b, 51c, 61 Substrate, 2, 42a, 42b, 42c, 42d, 52a, 52b, 52c, 62 First electrode, 3, 43a, 43b, 43c, 43d , 53a, 53b, 53c, 63 insulating layers, 4, 44a, 44b, 44c, 44d, 54a, 54b, 54c, 64 second electrodes, 5, 45a, 45b, 45c, 45d, 55a, 55b, 55c, 65 Semiconductor layer, 66 reflective layer, P incident light.

Claims (12)

A first electrode, an insulating layer stacked on the first electrode, a second electrode stacked on the insulating layer and not in contact with the first electrode, the first electrode, A photoelectric conversion element comprising a semiconductor layer in contact with both of the second electrodes. The photoelectric conversion element according to claim 1, further comprising a reflection layer on a surface of the semiconductor layer opposite to the first electrode. 3. The photoelectric conversion device according to claim 1, wherein the first electrode is made of a transparent conductive material. The photoelectric conversion device according to claim 3, wherein the second electrode and the insulating layer are transparent. The photoelectric conversion device according to claim 1, wherein the semiconductor layer is made of a photoconductive material. The photoelectric conversion device according to claim 1, wherein the semiconductor layer includes a region made of an electron-accepting material and a region made of an electron-donating material. The photoelectric conversion element according to claim 1, wherein a material forming the semiconductor layer forms a Schottky junction with the first electrode or the second electrode. The photoelectric conversion device according to claim 1, wherein the semiconductor layer is made of an organic material. 9. The photoelectric conversion device according to claim 1, wherein the first electrode and the second electrode are made of an organic material. The photoelectric conversion device according to any one of claims 1 to 9, wherein the insulating layer is made of an organic material. Forming a first electrode, forming an insulating layer on the first electrode, forming a second electrode on the insulating layer, exposing the first electrode; Forming a semiconductor layer in contact with both the first electrode and the second electrode, wherein the step of forming the semiconductor layer is a last step And performing the process so as to be in contact with the first electrode and the second electrode. The method according to claim 11, wherein at least one of the first electrode, the insulating layer, and the second electrode is formed using an inkjet printing method.

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