JP4430333B2 - Organic solar cell and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an organic solar cell and a manufacturing method thereof. More specifically, the present invention relates to a solar cell using an internal electric field by an organic / organic heterojunction and a method for manufacturing the solar cell.
[0002]
[Prior art]
Conventional solar cells using organic semiconductors are versatile, have low toxicity, have high processability and productivity, can be reduced in cost by mass production, and are flexible because of their flexibility. Although it has excellent features such as being easy, there is a problem that the energy conversion efficiency is low and the practical level is not reached.
[0003]
For example, a so-called Schottky barrier type element utilizing contact between metal-free phthalocyanine and aluminum has been reported (ROLoutfy et al., J. Chem. Phys. Vol. 71, p1211 (Non-patent Document 1)). However, since the aluminum of the electrode is oxidized by oxygen in the air, there is a problem that when the light intensity is increased, the conversion efficiency is lowered or the element is deteriorated with time.
[0004]
In addition, a stacked PN heterojunction solar cell (CW Tang, Appl. Phys. Lett. Vol. 45, p1144 (non-patent document 2)) in which a perylene derivative, which is an organic N-type semiconductor, is bonded to phthalocyanine instead of aluminum. It has been reported. This solar cell showed a conversion efficiency of 1% under simulated sunlight and showed the possibility of practical use. However, since the junction area is small and the region for charge separation is narrow, charge separation does not occur efficiently, There is a problem that it becomes difficult for current to flow to the external circuit. Therefore, the conversion efficiency is required to be further improved by about 10 times.
[0005]
In addition, solar cells using a mixed film of poly [(2-methoxy-5- (2'-ethylhexyloxy) 1-4-phenylenevinylene], a fullerene derivative of polyphenylene vinylene, which is a conductive polymer, etc. A bulk heterojunction solar cell using a mixed film of US Pat. No. 5,331,183 (Patent Document 1) is also proposed, which uses one organic material as another organic material. Since it is dispersed in the material, the junction area is wide and the area for charge separation is also wide, but the distance between the organic material molecules is large, and it is difficult to move the charge-separated carriers. There is a high probability that it will be deactivated before it reaches, and it has not reached the level of practical use.
[0006]
[Patent Document 1]
US Pat. No. 5,331,183
[Non-Patent Document 1]
ROLoutfy et al., J. Chem. Phys. Vol. 71, p1211
[Non-Patent Document 2]
CW Tang, Appl. Phys. Lett. Vol. 45, p1144
[0007]
[Problems to be solved by the invention]
This invention is made | formed in view of said problem, and makes it a subject to provide the manufacturing method by the solar cell which has high photoelectric conversion efficiency, and its easy process.
[0008]
[Means for Solving the Problems]
Thus, according to the present invention, the functional layer including the heterojunction surface formed by contacting the first organic material and the second organic material is sandwiched between the first electrode and the second electrode, and the first Organic material has a fine particle fusion laminated structure, and the second organic material exists on the surface and / or void of the fine particle fusion laminated structure The first organic material is a conductive polymer material and has a melting point higher than that of the second organic material. An organic solar cell is provided.
[0009]
According to the present invention, (a) on the first electrode, Consisting of fine particles A step of forming a fine particle laminate structure of a first organic material, (b) a step of fusing the fine particle laminate structure to form a fine particle fusion laminate structure, and (c) a first of the fine particle fusion laminate structure. Treating the organic material with the second organic material such that the second organic material is present in the surface and / or voids thereof to form a functional layer having a heterobonded surface; and (d) Forming a second electrode on the functional layer; And the first organic material used in the step (a) is a conductive polymer material and has a melting point higher than the melting point of the second organic material. In the step (b), fine particles are formed by heating. The temperature at which the particles are fused is not lower than the glass transition point of the fine particles and not higher than the melting point, and in the step (c), a second organic material is laminated on the fine particle fused laminated structure, Heating at a temperature lower than the melting point and higher than the melting point of the second organic material An organic solar cell manufacturing method is provided.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing the layer structure of the organic solar cell of the present invention. FIG. 1A shows the first embodiment, in which a substrate 101a, a first electrode 102a, a first organic material 103a having a fine particle fusion laminated structure, a part of which is a surface of a fine particle fusion laminated structure and / or a void. The second organic material 104a and the second electrode 105a existing therein are sequentially stacked. Here, when light is irradiated from the substrate side, the substrate 101a and the first electrode 102a are formed of a light-transmitting material. On the other hand, when the light is irradiated from the side opposite to the substrate, the second electrode 105a is formed of a light transmissive material. Here, “light-transmitting” means a property of transmitting light in a predetermined wavelength region, for example, a visible region, used in an organic solar cell with high efficiency.
[0011]
In the present invention, a functional layer including a heterojunction surface formed by contacting a first organic material and a second organic material is sandwiched between the first electrode and the second electrode, and the first organic material Has a fine particle fusion laminated structure, and the second organic material is present on the surface and / or voids of the fine particle fusion laminated structure.
[0012]
<About the fine particle fusion lamination structure>
The “fine particle fusion laminated structure” in the present invention means a structure in which fine particles are bonded to form a three-dimensional network. That is, the structure is a state in which a part of the interface between the fine particles is lost due to heat and light, the resistance value when the carrier moves between the fine particles is low, and the charge separated at the interface of different organic materials Since it can move easily, the probability that the generated carriers will reach the electrode increases.
[0013]
Figure 2 (a) This is the state before the fine particles have a fused structure. FIG. 2 (b) is a schematic diagram showing the fine particle fusion laminated structure in the organic solar cell of the present invention, and FIG. 2 (b) is a schematic diagram showing the structure of the fine particle aggregate in the organic solar cell. 2 (a) and 2 (b) , Fine In each of the particle aggregate structure and the fine particle fusion laminated structure, one row is cut out and displayed when fine particles are linearly arranged. In the figure, reference numeral 203 denotes a fine particle fusion laminated structure.
[0014]
Fig. 2 (a) Fine In the case of a particle structure, there is a discontinuous interface at the boundary between a particle and an adjacent particle. When the interface exists, carriers such as electrons and holes existing in one particle are prevented from moving due to trap levels and spatial gaps existing in the interface.
[0015]
On the other hand, in the case of the fine particle fusion laminated structure according to the present invention shown in FIG. 2B, the fine particles are bonded while the shape of the fine particles remains. That is, there is no grain boundary, and the bonding portion between the fine particles is continuous. For example, in the case of crystals, it means that the periodicity of the crystal is continuous at the bonding portion, and even in the case of amorphous, it means that the network of bonds between atoms is also continuous in the bonding portion. . In the case of a polymer, it means a state in which the molecular chain exists across the binding moiety. In addition, while the particles are bonded as described above, there are also voids between the particles.
[0016]
Therefore, in the case of the fine particle fusion laminated structure of the present invention shown in FIG. Fine Compared to the structure of a particle assembly, carriers such as electrons and holes existing in one particle can move smoothly to adjacent particles.
[0017]
The average particle diameter of the fine particles forming the first organic material 103a having the fine particle fusion laminated structure is about 10 nm to 1 μm, and preferably 20 nm to 500 nm. The particle size distribution of the fine particles is not particularly limited, and may be uniform or random. However, it is more preferable that the particles have a spherical and uniform particle size because temperature control in the fusion process of the fine particles is easy.
[0018]
The filling structure of the fine particle fusion laminated structure can be changed by the shape of the fine particles and the particle size distribution thereof. By changing the filling structure, it is possible to change the range of charge separation, the volume of the fine particle fusion laminated structure, and the volume ratio of the second organic material present in the voids. In general, when fine particles having a uniform particle size are precipitated in a solvent, they are regularly packed. Since regular packing has the same arrangement structure everywhere in the particle assembly, the unit cell that is the smallest unit may be considered. When spherical particles having a uniform particle diameter have a regular packing structure, a wide range of space ratios can be expressed continuously, but it is difficult to think that such an array structure actually exists. Random arrangement has no directionality and periodicity, and the particle arrangement varies depending on the location.
[0019]
In the case of the present invention, a network can be formed even if regular packing is not shown. Here, the volume ratio of the fine particle fusion laminated structure to the functional layer is preferably 50% or more in forming the fine particle network. Further, when the second organic material 104a is present on the surface and / or voids of the fine particle fusion laminated structure, if the proportion of the fine particle fusion laminated structure is too high, the second organic material becomes difficult to exist, and therefore 80% The following is preferable. Considering the ease of manufacture and the region where charge separation is performed, the ratio of the fine-particle fusion laminated structure to the functional layer is most preferably 60% or more and 70% or less.
[0020]
In order to allow the second organic material to be present in the surface and / or void in the first organic material forming the fine particle fusion laminated structure, the second organic material is dissolved or dispersed in an organic solvent, and the solution Alternatively, it is preferable that the functional layer is heated after the dispersion is applied to the fine particle fusion laminated structure.
[0021]
The film thickness of the functional layer composed of the first organic material forming the fine particle fusion laminated structure and the second organic material present in the surface and / or voids is about 10 nm to 50 μm, About 50 nm to 2000 nm is preferable. If the film thickness is too thin, an electrical short circuit is caused and it becomes difficult to show photoelectric conversion characteristics.
[0022]
<About organic materials for functional layers>
In the organic material, one of the surface of the first organic material 103a and / or the second organic material 104a existing in the voids of the fine particle fusion laminated structure is an electron-accepting organic material, and the other is an electron-donating organic material. It is.
[0023]
An electron-accepting organic material is a conjugated electron-spread π-electron compound in which charge carriers are electrons, and exhibits an N-type semiconductor characteristic stable in air. When the electron-accepting organic material is used for the first organic material, it is preferably insoluble or hardly soluble in the solvent to be dispersed and precipitated.
[0024]
For example, examples of the electron-accepting organic material include oligomers and polymers having pyridine and its derivatives as a skeleton, oligomers and polymers having quinoline and its derivatives as a skeleton, ladder polymers using benzophenanthrolines and derivatives thereof, and cyanopolyphenylene vinylene. And low molecular weight materials such as fluorinated metal-free phthalocyanines, fluorinated metal phthalocyanines and derivatives thereof, perylene and derivatives thereof, naphthalene derivatives, bathocuproine and derivatives thereof.
[0025]
The electron-donating organic material is a conjugated electron-spread π-electron compound in which charge carriers are holes, and exhibits stable P-type semiconductor characteristics in air. When the electron donating organic material is used for the first organic material, it is preferably insoluble or hardly soluble in the solvent to be dispersed.
[0026]
Examples of the electron-donating organic material include oligomers and polymers having thiophene and its derivatives as a skeleton, oligomers and polymers having phenylene vinylene and its derivatives as a skeleton, oligomers and polymers having thienylene vinylene and its derivatives as a skeleton, vinyl Oligomers and polymers having carbazole and its derivatives in the backbone, oligomers and polymers having pyrrole and its derivatives in the backbone, oligomers and polymers having acetylene and its derivatives in the backbone, oligomers and polymers having isothiaphene and its derivatives in the backbone, Polymer materials such as oligomers and polymers having heptadiene and its derivatives in the skeleton; metal-free phthalocyanines, metal phthalocyanines and their derivatives, diamines, phenyldiamines and the like Derivatives, acenes such as pentacene and derivatives thereof, porphyrin, tetramethylporphyrin, tetraphenylporphyrin, diazotetrabenzporphyrin, monoazotetrabenzporphyrin, diazotetrabenzporphyrin, triazotetrabenzporphyrin, octaethylporphyrin, octaalkylthioporphyrin Examples include low-molecular materials such as metal-free porphyrins such as azine, octaalkylaminoporphyrazine, hemiporphyrazine, chlorophyll, metalloporphyrins and derivatives thereof, cyanine dyes, quinone dyes such as merocyanine, benzoquinone, and naphthoquinone.
[0027]
As the central metal of metal phthalocyanine and metal porphyrin, magnesium, zinc, copper, silver, aluminum, silicon, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, tin, platinum, lead and other metals, metal oxides, Metal halides are used.
[0028]
Among the above electron-donating organic materials, for example, a conductive polymer material such as polythiophene is preferable because it can be easily produced using a unique polymer fine particle production technique such as a suspension polymerization method.
[0029]
The fine particle fusion laminated structure can be formed by applying energy such as heating and electron beam irradiation to the fine particle laminated structure and fusing adjacent fine particles together.
[0030]
When a conductive polymer material is used as the first organic material and the fine particles are stacked and then heated to fuse the fine particles, the temperature is preferably higher than the glass transition point and lower than the melting point. If the temperature is less than the glass transition point, it is not preferable because the fine particles hardly fusing and the charge transfer between the fine particles is not smoothly performed. On the other hand, heating at a temperature exceeding the melting point is not preferable because all voids formed by the fine particle laminated structure disappear. In order to perform charge transfer smoothly and increase the charge separation area, heating in the above temperature range is preferable.
It is particularly preferred that the first organic material is polyphenylene vinylene and the second organic material is poly (quinoxaline-5,8-diyl).
[0031]
<About the board>
Specific materials for the substrate 101a include metals such as aluminum and stainless steel, alloys, plastics such as polycarbonate and polyester, and the like. Moreover, glass, a transparent plastic, etc. can be used as a permeable substance.
[0032]
<About electrodes>
A transparent electrode is used as one of the first electrode 102a and the second electrode 105a that sandwich the functional layer.
These electrodes are not particularly limited as long as they have predetermined characteristics such as conductivity and light transmittance, and known materials such as metals, oxides, and polymers can be used. In general, the thickness of the electrode is preferably about 20 nm to 1 μm.
[0033]
In order to form ohmic contact with the electron-accepting organic material and transmit the irradiation light, it is preferable to use an electrode material having a small work function. In order to form ohmic contact with the electron donating organic material, it is preferable to use an electrode material having a high work function.
[0034]
Examples of the electrode material having a large work function include tin-doped indium oxide (ITO), gold, and platinum, and examples of the transparent electrode material include fluorine-doped tin oxide. Examples of the electrode material having a small work function include aluminum and indium.
[0035]
The electrode can be processed into a predetermined shape by a known method. In the case of two electrodes, the relationship between the electrodes and the functional layer may be that different organic materials may be in contact with the two electrodes separately as shown in FIG. As shown in (b), both of the first organic material forming the fine particle fusion laminated structure and the second organic material existing on the surface and / or in the void may be in contact with both electrodes. In order to prevent photooxidation, the functional layer and the electrode are preferably produced in a vacuum and in an inert gas such as nitrogen. Note that the figure numbers 101b to 105b in FIG. 1B correspond to the figure numbers 101a to 105a in FIG.
[0036]
Moreover, it is preferable that the first organic material forming the fine particle fusion laminated structure has a higher melting point than the second organic material. That is, an organic material having a melting point lower than that of the first organic material forming the fine particle fusion laminated structure 103a is used as the second organic material, and the second organic material is laminated on the fine particle fusion laminated structure, Then, heating is performed at a temperature lower than the melting point of the first organic material used in the fine particle fusion laminated structure and higher than the melting point of the second organic material. In this way, the fine particle fusion laminated structure maintains the fine particle network structure, and only the second organic material to be filled melts and exists on the surface and / or voids of the fine particle fusion laminated structure 103a. .
[0037]
When the melting point of the first organic material is higher than the melting point of the second organic material, after forming the fine particle fusion laminated structure, the molten second organic material is applied to the surface and without breaking the fine particle fusion laminated structure. / Or can be present in the voids. Thus, after forming the fine particle fusion laminated structure, the other organic material can be easily present on the surface and / or voids by utilizing the temperature difference between the melting points.
[0038]
<About electron transport layer and hole transport layer>
Further, a hole transport layer 303 is provided between the first or second electrode serving as the anode and the functional layer, and / or an electron transport layer 306 is disposed between the second or first electrode serving as the cathode and the functional layer. (See Example 2 and FIG. 3).
By introducing the electron transport layer or the hole transport layer, carriers separated by charge at the interface of the functional layer are smoothly transported to the electrode.
[0039]
As the molding material for the electron transport layer, electron accepting substances such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, tetracyaniniquinodimethane, and these electron accepting substances are used. There are molecularized ones.
[0040]
Molding materials for the hole transport layer include oxadiazole derivatives, pyrazoline derivatives, aromatic tertiary diamino compounds such as triphenylamine and benzylaniline, 1,2,4-triazine derivatives, hydrazone derivatives, quinazoline derivatives, benzofurans. Derivatives, α-stilbene derivatives, triphenylmethane derivatives, or polymers having a group consisting of these compounds in the main chain or side chain.
[0041]
The hole transport layer or the electron transport layer can be formed by a known method such as an evaporation method, a spin coating method, a spray method, a screen printing method, or an ink jet printing method.
[0042]
The thickness of the electron transport layer is not particularly limited as long as it is greater than or equal to the thickness that covers the functional layer. However, if it is too thick, the electron transport efficiency deteriorates, so that it is several nm to 1 μm, preferably about 10 nm to 500 nm. It is.
[0043]
The thickness of the hole transport layer is not particularly limited as long as it is greater than or equal to the thickness that substantially covers the first electrode 302, but if it is too thick, the hole transport efficiency deteriorates. It is about 10 nm to 500 nm.
[0044]
The manufacturing method of the solar cell of this invention is demonstrated.
The method for producing an organic solar cell of the present invention includes (a) a step of forming a fine particle laminated structure of a first organic material on a first electrode, and (b) fusing the fine particle laminated structure to each other. (C) a first organic material having the fine particle fusion laminated structure, and a second organic material so that the second organic material is present on the surface and / or voids thereof. Processing and hetero Contact A step of forming a functional layer having a mating surface; and (d) a step of forming a second electrode on the functional layer.
[0045]
After the first organic material fine particles dispersed in the solvent are deposited or coated on the first electrode of ITO formed by the conventional method, the solvent is removed by an evaporation method to form a fine particle laminated structure, and then heat or the like is applied. A fine particle fusion laminated structure is formed by fusing. Thereafter, the fine particle fusion laminated structure is immersed in the second organic material, and the solvent is evaporated to produce a functional layer existing on the surface and / or void of the fine particle fusion laminated structure of the first organic material. Thereafter, the second electrode is formed by a vacuum deposition method.
[0046]
By this manufacturing method, it is possible to form a network in which the interface between the fine particles is eliminated while maintaining the state of the fine particles.
The fine particles may be fused using heat. Since an organic material is used for the fine particles and the fine particles can be fused at a low temperature, a fine-particle fused laminated structure can be easily produced. An organic material having a lower melting point than the first organic material used for the fine particle fusion laminated structure 103a is used as the second organic material, and the melting point of the first organic material used for the fine particle fusion laminated structure 103a is larger. Heating at a temperature lower and higher than the melting point of the second organic material.
Moreover, it is preferable to carry out all the steps without exposing them to the atmosphere.
[0047]
As another production method of the present invention, an organic solar cell may be produced by the following method. The manufacturing method is a method of forming a fine particle laminated structure by precipitating fine particles dispersed in a solvent having specific properties.
[0048]
As the solvent having specific properties for dispersing the fine particles, a volatile solvent in which the first organic material constituting the fine particles is insoluble and the specific gravity is smaller than the specific gravity of the fine particles is used.
[0049]
First, fine particles composed of the first organic material are dispersed in a solution in which the second organic material is dissolved. After the fine particles are precipitated, the solvent in which the second organic material is dissolved is volatilized. By introducing this step, it is possible to easily produce a structure in which the fine particles have a high density.
[0050]
A fine particle stacked structure may be formed by applying fine particles of the first organic material dispersed in a solvent to the substrate and volatilizing the solvent. In this manufacturing method, after applying a solution in which fine particles are dispersed in a solvent and drying the solvent to form a structure in which the fine particles are laminated, energy is applied to the structure in which the fine particles are laminated by a method such as heating. A method of forming the fine particle fusion laminated structure 103a may be used. By introducing this step, a structure in which fine particles are laminated can be easily produced.
[0051]
【Example】
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.
Example 1
Examples of the material constituting the fine particle fusion laminated structure 103a include poly (phenylene vinylene) (PPV) which is an electron donating material, and the second organic material 104a filled in the void portion of the fine particle fusion laminated structure 103a. The case of using poly (quinoxaline-5,8-diyl) (P (5,8-Qx)), which is an electron-accepting material, will be described specifically by way of example.
[0052]
First, fine particles of PPV were dispersed in a toluene solution. The diameter of the fine particles was approximately 50 nm. Further, the concentration of the dispersion solution was about 2 wt%. Next, this dispersion solution was uniformly coated on the ITO electrode 102a formed on the quartz substrate 101a by a spray coating method. After the fine particles settled on the substrate by the action of gravity, the process waited for about 5 minutes until toluene was volatilized. After volatilization, the substrate on which the fine particles had been laminated was heated on a hot plate at a temperature of 150 ° C. for 3 minutes. By this step, the PPV fine particle fusion laminated structure 103a was formed. The film thickness of the fine particle fusion laminated structure 103a was about 700 nm. In addition, the ratio of the fine particle fusion layered structure 103a to the gap formed between the fine particles was approximately 7: 3.
[0053]
P (5,8-Qx) was present so as to be present in the surface and / or voids of the fine particle fusion laminated structure of PPV. Specifically, P (5,8-Qx) was dissolved in toluene to prepare a solution having a concentration of about 2 wt%. This solution was immersed in the PPV fine particle fusion laminated structure 103a formed on the ITO quartz substrate by a casting method. After this solution sufficiently permeated the voids of the fine particle fusion laminated structure 103a, toluene was volatilized. The film thickness of the functional layer was approximately 1000 nm.
After forming the functional layer as described above, the second electrode 105a was produced by vacuum deposition. The solar cell by this invention was able to be produced according to the above process.
Thus, the obtained organic solar cell showed high photoelectric conversion efficiency compared with the conventional product.
[0054]
(Example 2)
FIG. 3 is a schematic cross-sectional view for explaining an organic solar cell as a second embodiment of the present invention. As shown in FIG. 3, the substrate 301, the first electrode 302, the hole transport layer 303, the first organic material 304 having the fine particle fusion laminated structure, and the surface and / or the void existing on the surface of the fine particle fusion laminated structure. A functional layer made of two organic materials 305, an electron transport 306, and a second electrode 307 are sequentially stacked. Here, the hole transport layer 303 is in contact with the electron donating organic material of the functional layer. The electron transport layer 306 is in contact with the electron-accepting organic material of the functional layer.
[0055]
The concrete method of the manufacturing process of 2nd Example is shown below. The first electrode 302 was formed in the same manner as in Example 1.
Next, using a conductive polymer material such as poly (3,4-ethylenedioxythiophene: polystyrenesulfonate) (PEDOT: PSS), a hole transport layer 303 having a thickness of 100 nm is formed by spin coating. did. Next, a functional layer was formed in the same manner as in Example 1.
[0056]
After the functional layer was formed, the electron transport layer 306 was formed by vacuum deposition using bathocuproine (electron-accepting organic material). At this time, the thickness of the electron transport layer was 100 nm. Next, in the same manner as in Example 1, a second electrode 307 having a thickness of 200 nm was formed. Through the above steps, the solar cell of the second embodiment of the present invention was produced.
The organic solar cell thus obtained is Organic solar cell having the structure of the fine particle aggregate shown in FIG. High photoelectric conversion efficiency was shown.
[0057]
【The invention's effect】
According to the organic solar cell of the present invention, since the area of charge separation is large and the grain boundary between the fine particles of the functional layer is eliminated, it is continuous. Le Carriers move more smoothly than quasi-junction solar cells. For this reason, high photoelectric conversion efficiency can be obtained.
In addition, the organic solar cell manufacturing method of the present invention can form a structure in which fine particles are laminated by an easy process, and does not require a high temperature process.
Furthermore, by introducing an electron transport layer and / or a hole transport layer, the carrier between the functional layer and the electrode can be easily moved, and the photoelectric conversion efficiency can be further improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a layer configuration of an organic solar cell of the present invention (Example 1).
[Figure 2] Yes The structure of fine particle aggregate in solar cell Comparison It is a schematic diagram (a) and the schematic diagram (b) which shows the fine particle fusion | melting laminated structure in the organic solar cell of this invention.
FIG. 3 is a schematic cross-sectional view showing a layer structure of an organic solar cell of the present invention (Example 2).
[Explanation of symbols]
101a, 101b, 301 substrate (quartz substrate)
102a, 102b, 302 First electrode (ITO electrode)
103a, 103b, 203, 304 First organic material 104a, 104b, 305 of fine particle fusion laminated structure Second organic material present in surface and / or void of fine particle fusion laminated structure
105a, 105b, 307 Second electrode
303 hole transport layer
306 Electron transport layer

Claims (7)

A functional layer including a heterojunction surface formed by contacting the first organic material and the second organic material is sandwiched between the first electrode and the second electrode, and the first organic material is fused by fine particles. Having a laminated structure, wherein the second organic material is present on the surface and / or voids of the fine particle fused laminated structure ;
An organic solar cell , wherein the first organic material is a conductive polymer material and has a melting point higher than that of the second organic material .   The organic solar cell according to claim 1, wherein the first organic material is fine particles having an average particle diameter of 20 to 500 nm. The organic solar cell according to claim 1 or 2 , wherein the first organic material is fine particles made of polyphenylene vinylene, and the second organic material is poly (quinoxaline-5,8-diyl). A hole transport layer between the first or second electrode and the functional layer to the anode, and / or claim 1-3 having an electron-transporting layer between the second or first electrode and the functional layer of the cathode The organic solar cell according to any one of the above. The organic solar cell according to any one of claims 1 to 4, wherein a volume ratio of the fine particle fusion laminated structure to the functional layer is 50% or more and 80% or less. (A) forming a fine particle laminated structure of a first organic material made of fine particles on the first electrode;
(B) forming the fine particle fusion laminated structure by fusing the fine particle laminated structure to each other;
(C) treating the first organic material having the fine particle fusion laminated structure and the second organic material so that the second organic material is present on the surface and / or in the voids, thereby obtaining a hetero-bonding surface; And (d) forming a second electrode on the functional layer ,
The first organic material used in the step (a) is a conductive polymer material and has a melting point higher than that of the second organic material;
In the step (b), the temperature at which the fine particles are fused by heating is not less than the glass transition point of the fine particles and not more than the melting point,
In the step (c), a second organic material is laminated on the fine particle fusion laminated structure and heated at a temperature lower than the melting point of the first organic material and higher than the melting point of the second organic material. The manufacturing method of the organic solar cell characterized by these. The method for producing an organic solar cell according to claim 6 , wherein in step (a), fine particles of a first organic material dispersed in a solvent are applied to the first electrode, and the solvent is volatilized to form a fine particle laminated structure. .
Depends on 6 or 7

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