JPH11145501A - Photosensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the shunt current of a photosensor, and to improve photovoltaic characteristics by filling a pin hole existing in a power generation layer with a specific organic high-molecular material, regarding the photosensor with the power generation layer composed of an non-single crystal material. SOLUTION: In a photosensor with a power generation layer, in which a first conductive layer 103 constituted of a non-single crystal material, a substantially intrinsic semiconductor layer 104 configured of the non-single crystal material and a second conductive layer 105 constituted of the non-single crystal material are laminated in this order, the power generation layer is coated with an organic high-molecular layer, which has a resistance higher than the semiconductor layer, to which majority carriers in the second conductive layer can be moved and which consists of an organic high-molecular material, and pin holes 108, 109, 110 existing, while penetrating through to the power generation layer in the power generation layer are filled with the organic high-molecular material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic device having a small shunt current and excellent photovoltaic characteristics. More specifically, the present invention relates to a photovoltaic device having a power generation layer made of a non-single-crystal material, wherein a pinhole present in the power generation layer is filled with an organic polymer material.

[0002]

2. Description of the Related Art Numerous non-single-crystal photovoltaic devices have been proposed. Such a non-single-crystal type photovoltaic element is generally manufactured as follows. That is, a back reflection layer (lower electrode) made of ZnO, Ag, or the like is formed on a conductive substrate, and a p-layer made of a non-single-crystal material such as amorphous silicon is formed on the back reflection layer.
Semiconductor layer having semiconductor junction such as in-junction (power generation layer)
Is formed, and a light incident side electrode (upper electrode) made of a transparent conductive oxide such as ITO or SnO ₂ is formed on the semiconductor layer to obtain a photovoltaic element. In a non-single-crystal based photovoltaic device manufactured in this manner, particularly an amorphous silicon photovoltaic device, defects such as pinholes are formed in the semiconductor layer by dust or the like during film formation in the manufacturing of the photovoltaic device. It is known that such defects generated in the semiconductor layer cause shunts and short circuits, and lower the conversion efficiency of the photovoltaic element. In other words, the semiconductor between the lower electrode and the upper electrode of the photovoltaic element is lost due to the pinhole, and the lower electrode and the upper electrode are in direct contact with each other or have a low resistance even if the semiconductor layer is not completely lost. When a shunt or short circuit occurs, a current generated by light flows in parallel through the upper electrode and flows into a low-resistance portion of the shunt or short section, so that the generated current is lost. With such a current loss, the open-circuit voltage of the photovoltaic element decreases.

[0003] As described above, when a shunt or a short has occurred, it has been practiced to reduce the current loss by removing or insulating the upper electrode at that location. As a method of selectively removing the upper electrode of the shunt or short portion, for example, as disclosed in US Pat. No. 4,729,970, AlCl ₂ , ZnCl ₂ , SnCl ₂ , SnCl ₄ ,
Passivation for immersing the photovoltaic element and the counter electrode in a solution of a Lewis acid such as TiCl ₄ and applying a voltage to change the stoichiometric ratio of the transparent conductive oxide as the upper electrode to increase the passivation. There is a law. As a method of selectively insulating only a defective portion, for example, as disclosed in US Pat. No. 4,197,141,
The polycrystalline photovoltaic element is immersed in an electrolyte solution, and an electric field is applied to oxidize a defective portion based on the crystal grain boundary or lattice mismatch of the polycrystal or to deposit an insulator on the defective portion. Alternatively, there is a method of etching a defective portion. In addition to these, as disclosed in Japanese Patent Publication No. 62-4869, a photosensitive insulator is applied on an amorphous thin film, and a pinhole portion is filled with the photosensitive insulator, so that a light-transmitting substrate side is formed. There is a method in which only the photosensitive insulator in the pinhole is solidified by irradiating light, and the photosensitive insulator on the amorphous thin film is removed.

[0004]

However, any of the above-mentioned methods requires a complicated processing step, and has a problem that the apparatus for the processing is large-scale. In addition, there is a problem that the cost of the photovoltaic element obtained from the above is high. An object of the present invention is to provide a photovoltaic device having good characteristics that can be manufactured at relatively low cost without using complicated processing steps as in the prior art and without using large-scale equipment. To provide.

[0005]

A photovoltaic device according to the present invention, which solves the above-mentioned problems in the prior art and achieves the above object, comprises a first conductive layer made of a non-single-crystal material, A semiconductor layer formed of a crystalline material and a second conductive layer formed of a non-single-crystal material are stacked in this order on a conductive surface on a substrate; An organic polymer material having a higher resistance than that of the second conductive layer and capable of moving majority carriers in the second conductive layer, and applying the organic polymer material to a pinhole existing through the layer in the power generation layer. A transparent conductive film is deposited on the polymer material filled and applied on the power generation layer.

[0006]

FIG. 1 is a schematic sectional view of a typical example of a photovoltaic device according to the present invention. In FIG. 1, 101 indicates a conductive substrate, and 102 indicates a semiconductor layer (power generation layer) formed on the substrate 101. The semiconductor layer 102 includes a first conductive layer 103, a substantially intrinsic semiconductor layer (i-type semiconductor layer) 10
4 and the second conductive layer 105 are laminated in this order. Reference numeral 106 denotes an organic polymer layer formed of an organic polymer material and formed on the second conductive layer 105 of the semiconductor layer 102. Reference numeral 107 denotes a transparent electrode as an upper electrode formed on the organic polymer layer 106. 108,
Reference numerals 109 and 110 indicate pinholes, respectively. Note that the pinhole 108 penetrates through the second conductive layer 105 and reaches the vicinity of the interface with the i-type semiconductor layer 104, and the pinhole 109 includes the second conductive layer 105 and the i-type semiconductor layer 104. The pinhole 110 penetrates the first conductive layer 103 and reaches the vicinity of the interface between the i-type semiconductor layer 104 and the first conductive layer 103. It reaches the vicinity of the interface between the first conductive layer 103 and the conductive substrate 101 through the conductive layer 103. These pinholes 108, 1
09 and 110 are filled with the organic polymer material of the organic polymer layer 106. The photovoltaic element shown in FIG. 1 has a form in which light enters from the side opposite to the substrate 101. FIG. 2 is a schematic sectional view of another example of the photovoltaic device of the present invention. The photovoltaic element shown in FIG. 2 is the same as the photovoltaic element shown in FIG. 1 except that a light-transmitting conductive film is provided between the substrate and the first conductive layer. It has the same configuration as the power element. Hereinafter, each component of the photovoltaic element of the present invention will be described with reference to FIG.

[0007]

[Substrate] The substrate 101 may be conductive or electrically insulating. Furthermore, they may be translucent or non-translucent. When the electrode 101 is an electrically conductive material such as a metal, the electrode 101 can also serve as an electrode (lower electrode) for directly extracting a current. When the substrate 101 is an electrically insulating material such as a synthetic resin, the surface on the side on which the semiconductor layer 102 is formed is formed of a single metal or an alloy, and a current extracting electrode (lower portion) made of a light-transmitting conductive oxide. It is desirable to prepare electrodes. When the substrate 101 is a non-light-transmitting material such as a metal, it is preferable to form a reflective conductive layer on the substrate for improving the reflectance of long-wavelength light on the substrate surface. Further, for the purpose of preventing mutual diffusion of constituent elements between the substrate material and the semiconductor layer or as a buffer layer for preventing short circuit, a metal layer or the like as a reflective conductive layer is formed on the semiconductor layer on the substrate. Is preferably provided on the side where is formed. In the case where the substrate 101 is relatively transparent and a photovoltaic element having a structure in which light enters from the side of the substrate is used, a conductive layer made of a light-transmitting conductive oxide or a metal is used as the substrate. It is desirable to form it above. The surface of the substrate 101 may be a so-called smooth surface or a surface having minute irregularities.

[0008]

[Semiconductor Layer (Power Generation Layer)] The semiconductor layer 102 is formed of a non-single-crystal material of silicon-based material ranging from amorphous (including so-called microcrystal) to polycrystal. The semiconductor layer 102
Evaporation method, sputtering method, high frequency plasma CVD method, microwave CVD method, ECRCVD method, thermal CVD method, optical CVD
It can be formed by a known film formation method such as a method. Among these film forming methods, a plasma CVD method in which a source gas is decomposed by plasma to form a film on a substrate is preferably used. In the case of the plasma CVD method, for example, SiH ₄ or SiH ₆ ,
A gas mixture of H ₂ , He, or the like is decomposed by plasma, so that the i-type silicon-based non-single-crystal semiconductor layer 104 can be formed. The first conductive layer 103 is formed using an n-type or p-type silicon-based non-single-crystal material. Further, the second conductive layer 105 is formed using a p-type or n-type silicon-based non-single-crystal material. Such an n-type or p-type conductive layer (that is, an n-type or p-type semiconductor layer) is made of a silicon-based non-single-crystal material whose valence is controlled by an n-type or p-type valence electron controlling agent. As the n-type valence electron controlling agent, a compound containing an element of Group V of the periodic table is used. Examples of the group V element include P, N, As, and Sb. Preferred examples of compounds containing an element of group V, and a PH _3. As the p-type valence electron controlling agent, the periodic table II
A compound containing a Group I element is used. Examples of the group III element include B, Al, Ga, In and the like.
Preferred examples of the compound containing a Group III element include:
BF ₃ , B ₂ H _{6 and the} like. First conductive layer 103
And the second conductive layer 105 is formed of the i-type semiconductor layer 10.
4, it can be formed by a plasma CVD method. That is, for example, SiH ₄ or Si ₂ H ₆ , H ₂
Or compounds containing He and V group elements (such as PH ₃₎
Alternatively, it can be formed by subjecting a mixed gas composed of a compound containing a group III element (BF ₃ , B ₂ H _6, etc.) to plasma decomposition. The shunt resistance of the semiconductor layer 102 (power generation layer) is ideally infinite, but is generally infinite.
It is about KΩcm ² , and a shunt resistance of this level does not affect the conversion efficiency of the photovoltaic element. However, shunts and shorts due to defects exist, and 1KΩc
When it is less than m ^{2, the} photoelectric conversion efficiency is significantly reduced.

[0009]

[Organic polymer layer (organic polymer material)] Organic polymer layer 10
For 6, when the second conductive layer 105 is a p-type semiconductor layer, a hole transport type organic polymer material having a high drift mobility of holes as majority carriers is used. In the case where the second conductive layer 105 is an n-type semiconductor layer, an organic polymer material having a high drift mobility of electrons serving as majority carriers is used. Examples of the hole transport type organic polymer material include, for example, a molecular dispersion polymer material in which a low molecular compound such as a hydrazone compound is dispersed in a resin such as polyester, polystyrene, or polycarbonate; A carbon-based polymer material having a carbon-based main chain, such as polyvinylcarbazole, capable of transferring holes; a mixture of the above low-molecular compounds; and an organic compound such as an aliphatic or aromatic compound having a silicon atom as a main chain. Preferred examples include silicon-based polymer materials such as organic polysilanes having a substituent as a side chain. However, it is not limited to these. Preferred examples of the electron transport type organic polymer material include a molecularly dispersed resin material in which a low molecular compound such as a trinitrofluorenone compound is dispersed in a resin such as polyester, polystyrene, or polycarbonate. However, it is not limited to these. The organic polymer layer 106
When it is provided on the light incident side as shown in FIG. 1,
Desirably, it is translucent. The thickness of the organic polymer layer 106 only needs to be enough to fill the pinholes (108, 109, 110) existing in the semiconductor layer 102 (power generation layer). It is desirable to be thinner than the semiconductor layer 102 (power generation layer).
m or less is preferable. It is desirable that the drift mobility of the organic polymer material be as high as possible, but 1 × 10 ⁻⁷ cm ²
/ Vsec or more is preferable. It is desirable that the organic polymer material has a long carrier life, but 1 × 10 ⁻³ s
ec or more are preferred.

[0010]

[Upper Electrode (Transparent Electrode)] The upper electrode 107 is an electrode for extracting photovoltaic power generated in the semiconductor layer 102 (power generation layer), and forms a pair with the above-described lower electrode.
The upper electrode may be a light-transmitting material made of a conductive oxide or a light-shielding material made of a metal, but when it is on the light incident side as shown in FIG. Must be translucent.

[0011]

[Current collecting electrode] Although not shown in FIG.
In general, as shown in FIG.
A lid electrode is provided. In FIG. 5, reference numeral 501 denotes a grid.
And a bus bar 502. Grid electricity
The pole 501 is an electromotive force generated in the semiconductor layer 102 (power generation layer).
This is a current collecting electrode for extracting force. This grid electrode
501 denotes the first conductive layer 105 or the upper electrode 107
A suitable arrangement is determined from the magnitude of the sheet resistance of
It is almost skewered and does not obstruct the incidence of light as much as possible
Designed to be The specific resistance of the grid electrode is
Do not cause low series resistance of photovoltaic elements (solar cells)
Is required, and the desired specific resistance is 10^-2Ωcm ~
10^-FiveΩcm It is. The grid electrode 501 is made of Ag, P
Formed from metals such as t and Cu or alloys of these metals
be able to. Also, the grid electrode can be formed of Cu.
Can also be. In addition, the grid electrode is made of the metal or
A binder made of a polymer and the binder are added to the alloy powder.
Conductivity obtained by mixing the solvent of the inder at an appropriate ratio
It can be formed using a paste. Skewered grip
The formation of the gate electrode is performed by sputtering using a mask pattern.
Resistance, heating or CVD deposition method;
Method of patterning by etching after contacting;
A method of directly forming a grid electrode pattern by VD;
Or use a negative electrode mask for the grid electrode pattern.
What to do by forming after plating
Can be. In addition, printing the conductive paste described above
It can be performed by a forming method. Grid electrode
In the method of printing and forming a conductive paste,
When printing by screen printing, grid electrode
Can be formed with high productivity. The screen printing method,
Desired putter on mesh made of nylon or stainless steel
Conductive paste using a screen
It is used as a printing ink.
It can be as small as about 50 μm. As a printing machine
A commercially available screen printing machine is suitably used. School
Lean-printed conductive paste crosslinks the binder
And in a drying oven to evaporate the solvent. Ba
Subbar 502 controls the current flowing through grid electrode 501.
It is an electrode for collecting at one end. The busbar is A
Metals such as G, Pt, Cu, alloys of these metals, or
Can be composed of C. The form of the bus bar 502
Then, wire or foil may be attached
However, the same conductive paste as the grid electrode 501 is used.
May be used. For example, copper foil or
Or tin-plated copper foil.
Is used with an adhesive.

When the photovoltaic element (solar cell) manufactured as described above is used outdoors, encapsulation is performed by a known method in order to improve weather resistance and maintain mechanical strength. It is modularized. Regarding the encapsulation material used for the encapsulation, specifically, the adhesive layer, EVA (ethylene-ethylene) in terms of adhesion to a photovoltaic element (solar cell), weather resistance, and a buffer effect. Vinyl acetate copolymer) is preferably used. Further, in order to further improve moisture resistance and scratch resistance, a fluorine-based resin is laminated as a surface protective layer. Examples of the fluorine-based resin include a polymer TFE of tetrafluoroethylene (such as Teflon manufactured by DuPont), a copolymer ETFE of tetrafluoroethylene and ethylene (such as Tefzel manufactured by DuPont), and polyvinyl fluoride (manufactured by DuPont) Tedlar, etc.), polychlorofluoroethylene CTF
E (manufactured by Daikin Industries, Ltd.).
The lamination of these resins together with a photovoltaic element (solar cell) can be performed by using a commercially available device such as a vacuum laminator, for example, by thermocompression bonding in a vacuum.

Hereinafter, the operation and effect of the present invention will be described with reference to FIGS. FIG. 4 is a band model diagram of the photovoltaic device (solar cell) of the present invention. In FIG. 4, reference numeral 401 denotes a conductive substrate, and 402 denotes a first substrate.
403, an i-type semiconductor layer, 404, a second conductive layer, 405, an organic polymer layer (organic polymer material), 406
Is an upper electrode. FIG. 4A is a band model diagram in the case where there is substantially no pinhole, and FIG. 4B shows that the pinhole penetrates through the second conductive layer and that the conductive layer and the i-type layer are separated from each other. When reaching near the interface (see 108 in FIG. 1)
4C is a band model diagram. FIG. 4C shows a case where a pinhole penetrates the second conductive layer and the i-type layer and reaches near the interface between the i-type layer and the first conductive layer (FIG. FIG. 4D is a band model diagram of FIG. 1 and FIG. 4D is a band model diagram in which a pinhole penetrates through the second conductive layer, the i-type layer, and the first conductive layer to form the first conductive layer and the conductive substrate. FIG. 4 is a band model diagram when the area reaches the vicinity of the interface (see 110 in FIG. 1).

In the case of FIG. 4A, the semiconductor layer (power generation layer)
In the portion where (102) is coated with the organic polymer material (106, 405), holes generated by light in the i-type layer (104, 403) pass through the second conductive layer (105, 404). The organic polymer material (106, 405) in which majority carriers in the second conductive layer can move is moved, and the upper electrode (1) is moved.
07, 406), the organic polymer material (106, 405) does not affect the operation as a photovoltaic element. 4B, that is, the second conductive layer (10) as a part of the semiconductor layer (power generation layer) (102).
In the pinhole 108 in which (5,404) has been lost, the applied electric field is locally increased in that portion because the thickness of the semiconductor layer (power generation layer) is reduced, so that breakthrough is easily caused. An organic polymer material (10
6,405), the applied electric field does not locally increase, and the holes photo-generated in the i-type layer (104, 403) move through the organic polymer material (106, 405),
It is collected by the upper electrodes (107, 406) and contributes to power generation. In the case of FIG. 4C, that is, the semiconductor layer (power generation layer) (10
2) The pinhole 10 in which the second conductive layer (105, 404) and the i-type layer (104, 403) are lost as part of
9 has a large number of carriers in the first conductive layers (103, 402), and a large short-circuit current flows due to direct contact of the upper electrodes (107, 406). When the pinhole 109 is filled with the organic polymer material (106, 405), the first
Carriers of the conductive layers (103, 402) are electrons, so that the hole transport type organic polymer material (106, 40) is used.
5), the current loss due to a shunt current or the like generated in the pinhole can be reduced. FIG.
In the case shown in (d), namely, the semiconductor layer (power generation layer) (10
A large short-circuit current flows in the pinhole 110 in which part of 2) is lost as a whole, and the shunt resistance is significantly reduced. An organic polymer material (10
6,405), the organic polymer material (106, 405) is sandwiched between the conductive substrate (101, 401) and the upper electrode (107, 406). An organic polymer material (106, 4) is transferred from the conductive substrate (101, 401) or the upper electrode (107, 406).
05) is sufficiently small (Schottky junction), the short-circuit current is small, but even if the carrier injection is sufficiently large (ohmic contact), it is limited by the resistance of the organic polymer material (106, 405). Current. Therefore, the organic polymer material (106, 405) is made of the i-type layer (10
4,403), the pinhole 1
The short-circuit current flowing through 10 becomes small.

[0015]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

[0016]

Embodiment 1 In this embodiment, a photovoltaic element (solar cell) having the structure shown in FIG. 1 was manufactured. Stainless steel substrate 1
On the first conductive layer 1 made of an n-type a-Si: H film having a thickness of 100 ° using a plasma CVD device (not shown)
03, i-type a-Si: H film having a thickness of 1200 °
Mold layer 104, thickness of 100 ° made of p-type a-Si: H film
The second conductive layer 105 was laminated to form a semiconductor layer 102 (power generation layer). The obtained product is taken out of the plasma CVD apparatus, and a polycarbonate resin and a hydrazone compound [4- (diethylamino) benzaldehyde diphenylhydrazone] are mixed on the second conductive layer 105 at a weight dispersion ratio of 1: 1 and dissolved in dioxane. The organic polymer material obtained by the ultrasonic dispersion treatment is
Was applied by a dip coating method. The film thickness was controlled by the pulling speed, the solution temperature, and the solution concentration, so that the film thickness at a portion other than the pinhole was 100 ± 50 °. At this time, the pinholes 108, 109 and 110 were filled with the organic polymer material 106. After coating, 1 in vacuum
It was dried at 50 ° C. for 15 minutes. Thus, the semiconductor layer 1
02 (electric power generation layer), the organic polymer layer 106 made of an organic polymer material is coated with an ITO (In
_{A 2} O ₃ + SnO ₂ ) film was vacuum deposited to form an upper electrode 107. The element thus obtained was set on a screen printing machine (not shown), and as shown in FIG.
cm grid electrodes (501, see FIG. 5) at 1 cm intervals
Printed with. At this time, the conductive paste used had a composition comprising 70 parts by weight of an Ag filler, 30 parts by weight of a polyester binder, and 20 parts by weight of ethyl acetate as a solvent. After printing, place the resulting product in an oven for 150
C. for 30 minutes to cure the conductive paste. Next, a bus bar (50 mm) made of a copper foil with an adhesive having a width of 5 mm is used.
2, see FIG. 5) as shown in FIG. Thus, a single cell type photovoltaic element (solar cell) having a size of 30 cm × 30 cm was obtained. By repeating the above method, ten photovoltaic elements (solar cells) were produced. Each of the obtained photovoltaic elements was encapsulated as follows. That is, EVA is laminated on the upper and lower sides of the photovoltaic element, and a fluororesin film ETFE (ethylene tetrafluoroethylene) (Tefzel manufactured by DuPont) is laminated on the upper and lower sides of the EVA. Then, vacuum lamination was performed. Thus, ten photovoltaic element (solar cell) modules were obtained.

[0017]

[Evaluation] The obtained module was evaluated as described below. (1) The initial characteristics were evaluated as follows. That is, the voltage-current characteristics in the dark state were measured, and the shunt resistance was calculated from the inclination near the origin, and found to be 15 KΩcm ² ± 5 KΩc.
m ² , good characteristics and little variation. (2) The reliability test was performed based in part on the moisture resistance test B-2 defined in the environmental test method and the durability test method of the crystalline solar cell module of Japanese Industrial Standard C8917.
That is, first, the sample is put into a thermo-hygrostat capable of controlling the temperature and humidity, and the temperature is set at 85 ° C. (relative humidity 90 to 93%) to 200 ° C.
Left for hours. Next, the shunt resistance of the sample after completion of the test was measured in the same manner as in the initial test.
% Reduction rate. As a result, all the modules were found to be rich in moisture resistance. From the above evaluation results, it can be seen that the photovoltaic element (solar cell) of the present invention has good yield, good characteristics, and high durability (moisture resistance).

[0018]

Comparative Example 1 Ten photovoltaic element (solar cell) modules were produced in the same manner as in Example 1 except that the organic polymer material was not applied. The obtained module was evaluated in the same manner as in Example 1. As a result, the initial shunt resistance is 8KΩcm ² ± 1K
Ωcm ² , and the shunt resistance after the moisture resistance test was reduced by an average of 65% from the initial value. From the obtained evaluation results, the photovoltaic element (solar cell) obtained in Comparative Example 1
Was found to be clearly inferior to that obtained in Example 1.

[0019]

Embodiment 2 In this embodiment, a photovoltaic element (solar cell) having the structure shown in FIG. 2 was manufactured. Glass substrate 201
A SnO ₂ film was vacuum-deposited as a light-transmitting conductive film 202 on the substrate. On the translucent conductive film 202, a first conductive layer 204 made of a p-type a-Si: H film having a thickness of 100 ° and an i-type layer 205 having a thickness of 1200 ° are formed by using a plasma CVD apparatus (not shown). A second conductive layer 206 made of an n-type a-Si: H film and having a thickness of 100 ° was stacked to form a semiconductor layer 203 (power generation layer). The resulting product is taken out of the plasma CVD apparatus, and a polyester resin and an electron transporting material (trinitrofluorenone) are mixed at a weight dispersion ratio of 1: 1 on the second conductive layer 206, dissolved in dimethylformamide, and ultrasonically dispersed. The organic polymer material obtained by the
7 was applied by a dip coating method. Example 1
Was controlled in the same manner as in the above, so that the film thickness in the portion other than the pinhole was 100 ± 50 °. At this time, the pinhole 209 was filled with the organic polymer material. After the application, the coating was dried at 180 ° C. for 30 minutes in a vacuum. As described above, the ITO film having a thickness of 620 ° is vacuum-deposited on the organic polymer layer 207 made of a polymer organic material applied on the semiconductor layer 203 (power generation layer), and the upper electrode 2
08. Thereafter, a grid electrode was formed in the same manner as in Example 1, and a bus bar was attached to obtain a single-cell type photovoltaic element (solar cell). By repeating the above method, ten photovoltaic elements (solar cells) were produced. Each of the obtained photovoltaic elements was encapsulated in the same manner as in Example 1 to obtain ten photovoltaic element (solar cell) modules. The obtained module was evaluated in the same manner as in Example 1.
As a result, the initial shunt resistance is 16 KΩcm ² ± 2K
Ωcm ² , good characteristics, and little variation. Further, the shunt resistance after the moisture resistance test was reduced by about 7% on average with respect to the initial stage, and it was found that each module was rich in moisture resistance. From the above evaluation results, it can be seen that the photovoltaic element (solar cell) of the present invention has good yield, good characteristics, and high durability (moisture resistance).

[0020]

Comparative Example 2 Ten photovoltaic element (solar cell) modules were produced in the same manner as in Example 2 except that the organic polymer material was not applied. The obtained module was evaluated in the same manner as in Example 1. As a result, the initial shunt resistance is 7KΩcm ² ± 1K
Ωcm ² , and the shunt resistance after the moisture resistance test was reduced by an average of 72% from the initial value. From the obtained evaluation results, the photovoltaic element (solar cell) obtained in Comparative Example 2
Was found to be clearly inferior to that obtained in Example 2.

[0021]

Embodiment 3 In this embodiment, a triple cell type photovoltaic element (solar cell) shown in FIG. 3 was manufactured. In FIG. 3, reference numeral 301 denotes a substrate, 302 denotes a reflective conductive layer, and 303 denotes a buffer layer. I is a first semiconductor layer (bottom cell), and the bottom cell is a first conductive layer 304
(N-type semiconductor layer), a three-layered i-type semiconductor layer a (consisting of a first i-type semiconductor layer 305, a second i-type semiconductor layer 306, and a third i-type semiconductor layer 307), and And two conductive layers 308 (p-type semiconductor layers). II is the second
Of the first conductive layer 309 (n-type semiconductor layer), the three-layered i-type semiconductor layer b (the first i-type semiconductor layer 310, the second i-type semiconductor layer). The semiconductor layer 311 and the third i-type semiconductor layer 312), and the second conductive layer 313 (p-type semiconductor layer). III is a third semiconductor layer (top cell). The top cell includes a first conductive layer 314 (an n-type semiconductor layer, a single-layer i-type semiconductor layer 315, and a second conductive layer 316 (p Reference numeral 317 denotes an organic polymer layer made of an organic polymer material, and reference numeral 318 denotes an upper electrode.
Was prepared as follows. Stainless steel substrate 301
An Ag film having a thickness of 4000 と し て was formed as the reflective conductive layer 302 by DC sputtering, and a ZnO film having a thickness of 1 μm was formed as the buffer layer 303. On the ZnO film as the buffer layer 303, the bottom cell I, the middle cell II, and the top cell I are formed by a plasma CVD method.
II were stacked in this order. That is, high frequency plasma CV
A 300Å thick n-type semiconductor layer 304 is formed by the D method at 300Å.
Then, an i-type semiconductor layer 305 having a thickness of 100 ° is formed.
An i-type semiconductor layer 306 having a thickness of Å was formed, an i-type semiconductor layer 307 having a thickness of 100 さ ら に was formed by a high-frequency plasma CVD method, and a p-type semiconductor layer 308 having a thickness of 100 つ い was formed. Thus, a bottom cell I was formed. Next, an n-type semiconductor layer 3 having a thickness of 100 ° is formed by a high-frequency plasma CVD method.
09, followed by a 100 ° thick i-type semiconductor layer 310.
Is formed, and 1 is further formed by microwave plasma CVD.
An i-type semiconductor layer 311 having a thickness of 2,000 mm is formed, and an i-type semiconductor layer 3 having a thickness of 100
12 and then a p-type semiconductor layer 313 having a thickness of 100 °
Was formed. Thus, a middle cell II was formed. Subsequently, an n-type semiconductor layer 314 having a thickness of 100 mm is formed by a high-frequency plasma CVD method, an i-type semiconductor layer 315 having a thickness of 1000 mm is formed, and a p-type semiconductor layer 316 having a thickness of 100 mm is formed by a low-frequency plasma CVD method. did. Thus, a top cell III was formed. On the p-type semiconductor layer 316 of the top cell III thus formed, the same organic polymer material as used in Example 1 was used.
No. 17 was applied by a dip coating method. The film thickness was controlled in the same manner as in Example 1 so that the film thickness of the portion other than the pinhole was 100 ± 50 °. At this time, the pinhole 319 was filled with the organic polymer material. After the application, the coating was dried at 150 ° C. for 15 minutes in a vacuum. On the organic polymer layer 317 thus formed, a film thickness of 8
A 70 ° ITO film was vacuum deposited to form an upper electrode 318. Thereafter, a grid electrode was formed in the same manner as in Example 1, and a bus bar was attached to obtain a triple-cell type photovoltaic element (solar cell). By repeating the above method, ten photovoltaic elements (solar cells) were produced. Each of the obtained photovoltaic elements was encapsulated in the same manner as in Example 1 to obtain ten photovoltaic element (solar cell) modules. The obtained module was evaluated in the same manner as in Example 1. As a result, the initial shunt resistance was 16 KΩcm ² ± ² KΩcm ² , good characteristics, and little variation. In addition, the shunt resistance after the moisture resistance test was reduced by about 5% on average with respect to the initial stage, and it was found that all the modules were rich in moisture resistance. From the above evaluation results, it can be seen that the photovoltaic element (solar cell) of the present invention has good yield, good characteristics, and high durability (moisture resistance).

[0022]

Comparative Example 3 Ten photovoltaic element (solar cell) modules were produced in the same manner as in Example 3, except that the organic polymer material was not applied. The obtained module was evaluated in the same manner as in Example 1. As a result, the initial shunt resistance was 10 KΩcm ² ± 2.
KΩcm ² , and the shunt resistance after the moisture resistance test was reduced by an average of 35% from the initial value. From the obtained evaluation results, it was found that the photovoltaic device (solar cell) obtained in Comparative Example 3 was clearly inferior to that obtained in Example 3.

[0023]

According to the photovoltaic device of the present invention, as is apparent from the above description, the organic polymer layer has a high resistance, reduces shunts or short-circuits at pinhole portions, and reduces photocurrent at portions other than pinholes. Since it has a function of flowing to the upper electrode, excellent photovoltaic characteristics with small shunt current can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a single-cell type photovoltaic element constituted by a non-single-crystal semiconductor, which is an example of the photovoltaic element of the present invention.

FIG. 2 is a schematic cross-sectional view of a single-cell type photovoltaic device made of a non-single-crystal semiconductor, which is an example of the photovoltaic device of the present invention.

FIG. 3 is a schematic cross-sectional view of a triple-cell type photovoltaic device made of a non-single-crystal semiconductor, which is an example of the photovoltaic device of the present invention.

FIG. 4 is a band model diagram used to explain the operation of the photovoltaic device of the present invention.

FIG. 5 is a schematic diagram showing wiring on a light incident side surface of the photovoltaic device of the present invention.

[Explanation of symbols]

101, 201, 301, 401 Substrate 102, 203 Semiconductor layer (power generation layer) 202 Translucent conductive film 103, 204, 402 First conductive layer (n-type or p-type)
Semiconductor layer) 104, 205, 403 Substantially intrinsic semiconductor layer (i
Semiconductor layer) 105, 206, 404 Second conductive layer (p-type or n-type)
Type semiconductor layer) 106, 207, 317, 405 Organic polymer layer 107, 208, 318, 406 Upper electrode (translucent conductive) 108, 109, 110, 209, 319 Pinhole 302 Reflective conductive layer 303 Buffer layer 304, 309, 314 n-type semiconductor layer by high-frequency plasma CVD 305, 307, 310, 312, 315 i-type semiconductor layer by high-frequency plasma CVD 308, 313 p-type semiconductor layer by high-frequency plasma CVD 316 low-frequency plasma CVD Semiconductor layers 306, 311 by microwave plasma CVD
Type semiconductor layer 501 grid electrode 502 bus bar

Claims (7)

[Claims] A first conductive layer made of a non-single-crystal material; a substantially intrinsic semiconductor layer made of a non-single-crystal material; and a second conductive layer made of a non-single-crystal material. In a photovoltaic device having a power generation layer laminated in order, the organic polymer layer made of an organic polymer material having a higher resistance than the semiconductor layer and capable of moving majority carriers in the second conductive layer is provided. Applied on the power generation layer,
A photovoltaic element, wherein a pinhole penetrating through the power generation layer through the layer is filled with the organic polymer material. 2. The photovoltaic device according to claim 1, wherein said first conductive layer is n-type and said second conductive layer is p-type. 3. The photovoltaic device according to claim 2, wherein the organic polymer material constituting the organic polymer layer is a hole transport type organic polymer material. 4. The organic polymer material of the positive transport type according to claim 3, wherein the polymer material is selected from a molecular dispersion organic polymer material, a carbon organic polymer material, and a silicon organic polymer material. Photovoltaic element. 5. The photovoltaic device according to claim 1, wherein said first conductive layer is p-type, and said second conductive layer is n-type. 6. The organic polymer material constituting the organic polymer layer is an electron transport type organic polymer material.
3. The photovoltaic device according to claim 1. 7. The photovoltaic device according to claim 6, wherein the electron transport type organic polymer material is a molecularly dispersed resin material obtained by dispersing a low molecular weight organic compound in an organic resin.