JPH0563220A - Photovoltaic element and manufacture thereof - Google Patents

Abstract

(57) [Summary] [Object] The present invention improves the adhesion between a glass support and a transparent electrode so that it can be photo-excited even when left in a high temperature and high humidity environment for a long time or for a long time of ultraviolet irradiation. It is an object of the present invention to provide a photovoltaic element and a method for manufacturing the same, in which the characteristics of the power element (for example, short circuit photocurrent, photovoltaic, fill factor, etc.) are much less deteriorated than in the prior art. The present invention provides a substrate with a transparent electrode, which is formed by forming a transparent electrode formed of at least one layer selected from a tin oxide layer and an indium-tin oxide layer on a glass support. In a photovoltaic device in which at least a p-type layer, an i-type layer, an n-type layer and a conductive layer made of a crystalline silicon-based semiconductor are laminated, tin atoms decrease from the surface on which the transparent electrode is formed toward the inside. So that it is distributed in the glass support.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a glass support, on which a non-single crystal semiconductor layer containing silicon atoms and a conductive layer are laminated on a substrate with a transparent electrode formed by depositing at least tin oxide. The present invention relates to a configured photovoltaic cell such as a solar cell and an optical sensor, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Transparent electrodes are an important component relating to the capability of photovoltaic devices. Conventionally, tin oxide and indium oxide are used for such transparent electrodes,
The film was deposited by a spray method, a vacuum deposition method, an ion plating method, a sputtering method, or the like.

The light transmittance and the specific resistance of the transparent electrode thus deposited are parameters directly related to the performance of the photovoltaic element. Further conditions for depositing transparent electrodes,
For example, the substrate temperature, the degree of vacuum, the deposition rate, etc. are important parameters that affect the quality of the semiconductor layer film adjacent to the transparent electrode.

The relationship between the characteristics of a photovoltaic element and the transparent electrode in recent years is as follows: Optica1 absorption of transparnt condu
cting oxides and power, dissipation in a-Si: H pin s
o1arcells measured by photohermal deflection spect
roscopy "F. Leblanc, J. Perrin et.al. Technica1 dig
est of the internatinal PVSEC-5.Kyoto.Japan 1990,2
53. and "Improvement of interface properties of TCO
/ p-layer in pin-type amorphous silicon solar cell
s "Y.Ashida, N.Ishiguro et.al. Technical digest of
the international PVSEC-5. Kyoto, Japan, 1990, 36
It is considered in 7.

Further, as a method for lowering the resistance of the transparent electrode, a technique using a transparent electrode having an indium oxide film and a tin oxide film laminated is disclosed in Japanese Patent Laid-Open No. 54-134396.

[0006]

Although the above-mentioned conventional photovoltaic element has excellent characteristics, further improvement in various characteristics is desired.

According to the present invention, by improving the adhesion between the glass support and the transparent electrode, the characteristics of the photovoltaic element (for example, even when left in a high temperature and high humidity environment for a long time or irradiated with ultraviolet rays for a long time (for example, , A short-circuit photocurrent, a photovoltaic power, a fill factor, etc.) are much less deteriorated than in the prior art, and a manufacturing method thereof.

[0008]

According to a first aspect of the present invention to solve the above-mentioned problems, a photovoltaic element of the present invention is a transparent film formed of at least one of a tin oxide layer and an indium-tin oxide layer. Photovoltaic device in which at least a p-type layer, an i-type layer and an n-type layer made of a non-single crystalline silicon semiconductor, and a conductive layer are laminated on a substrate with a transparent electrode formed by forming electrodes on a glass support. In, the tin atoms are distributed in the glass support so as to decrease inward from the surface on which the transparent electrode is formed.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a photovoltaic element, wherein a tin metal layer or a tin oxide layer is deposited on a glass support and then annealed to carry out the tin metal layer or the tin oxide layer. A tin atom in the layer is diffused inside the glass support, and then the tin metal layer is oxidized to form a tin oxide layer to form a transparent electrode, and at least a non-single crystalline silicon-based semiconductor is formed. The p-type layer, the i-type layer, the n-type layer, and the conductive layer are formed.

[0010]

In the present invention, since the glass support contains tin atoms of the same kind as one constituent atom of the transparent electrode in a distributed manner, the adhesion between the transparent electrode and the glass support is improved, and high temperature and high humidity are provided. It is possible to prevent deterioration of characteristics such as short-circuit photocurrent, photovoltaic power, and fill factor in the photovoltaic element even under environment and irradiation with ultraviolet rays for a long time.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The detailed constitution of the present invention will be explained below as embodiments.

(Element Structure) An example of the structure of the photovoltaic element of the present invention shown in FIG. 1 is shown. The structure shown in FIG. 1 is a single structure, and a collector electrode 108, a transparent electrode 107, a p-type (or n-type) are formed on a glass support 101 in which tin atoms are distributed.
Type non-single-crystal silicon semiconductor layer 106, i-type (substantially intrinsic) non-single-crystal silicon semiconductor layer 10
5, n-type (or p-type) non-single-crystal silicon semiconductor layer 104, p-type (or n-type), reflection increasing layer 103, light reflecting layer (conductive) 102, conductive layer (and / or protective layer) 1
It is composed of 10.

The photovoltaic element of the present invention shown in FIG. 2 has a tandem structure, and a glass support 2 having tin atoms distributed therein.
01, a collector electrode 208, a transparent electrode 207, and a p-type (or n-type) non-single-crystal silicon-based semiconductor layer 206b, i.
Type (substantially intrinsic) non-single-crystal silicon semiconductor layer 206b, n-type (or p-type) non-single-crystal silicon semiconductor layer 204b, p-type (or n-type) non-single-crystal silicon semiconductor layer 206a , I-type (effectively intr
insic) non-single-crystal silicon semiconductor layer 205 and n-type (or p-type) non-single-crystal silicon semiconductor layer 204
a, a reflection increasing layer 203, a light reflecting layer (conductive) 202, and a conductive layer (or / and protective layer) 210.

Although not shown, a triple photovoltaic element in which pin units are laminated in three layers is also a photovoltaic element suitable for the present invention.

(Substrate, Glass support) The substrate of the present invention is
It is a substrate with a transparent electrode in which a transparent electrode is laminated on a glass support.

Here, as the glass support, the electrical characteristics (high electrical resistance), dielectric characteristics (small refractive index), mechanical characteristics (hard to break), and thermal characteristics (high softening point) of glass are used. ) Etc., and may be appropriately selected.

Considering the above points, for example, borosilicate glass, barium borosilicate glass, aluminosilicate glass, and quartz glass are preferable as the glass support of the photovoltaic element of the present invention.

From the viewpoint of mechanical strength, the glass support of the photovoltaic element of the present invention has a thickness of 0. l-10m
m is preferred.

A glass substrate having tin atoms distributed on a glass support is formed, for example, as follows.

First, tin metal or tin oxide is deposited on the glass support made of borosilicate glass, barium borosilicate glass, aluminosilicate glass, quartz glass or the like by vapor deposition, sputtering or the like. In addition, when depositing tin oxide, you may use a reactive deposition method. That is, for example, in the case of depositing by sputtering, when tin metal is used as a target and sputtering is performed in an oxidizing atmosphere, reactive sputtering is performed and tin oxide can be deposited.

The tin atoms can be exponentially distributed by heating to near the softening point of each glass and annealing, and annealing for a long time at a temperature below the softening point of the glass. The details will be described below.

A suitable layer thickness of the tin metal or tin oxide deposited on the glass support for containing tin atoms in the glass is 10 to 1000Å. When the tin atom is diffused into the glass support, the temperature of the glass support and the annealing time are 0.1 to 0.1 at the softening point temperature (600 to 800 ° C.) in the case of borosilicate glass and barium borosilicate glass. 10 hours at a temperature below the softening point (400 to 600 ° C.) for 5 to 100 hours. In the case of aluminosilicate glass, the temperature at the softening point (700 to 90).
At 0 ° C. 1 to 20 hours, the temperature below the softening point (400
~ 700 ° C) for 10 to 100 hours, and in the case of quartz glass, 0.1 at the softening point temperature (l200 to 1800 ° C).
~ 30 hours, temperature below softening point (500-1200 ° C)
And 10 to 200 hours are preferable conditions.

The annealing atmosphere is an important factor when performing such an annealing method. As the annealing atmosphere, an inert gas atmosphere of helium, neon, argon, krypton, xenon, etc., a hydrogen gas atmosphere or a nitrogen gas atmosphere can be mentioned as a preferable atmosphere. The pressure of the gas atmosphere is 1 m from atmospheric pressure
Torr is mentioned as a preferable range.

Further, as a method of distributing tin atoms, which are constituent atoms of the transparent electrode, on the glass support, an ion implantation method can be mentioned.

(Transparent Electrode) In the photovoltaic element of the present invention, a transparent electrode composed of a tin oxide layer or an indium-tin oxide layer is used as the transparent electrode. The tin oxide layer may have a laminated structure of two or more indium-tin oxide layers.

The transparent electrode of the photovoltaic element of the present invention is preferably deposited by, for example, a sputtering method or a vacuum evaporation method.

As a sputtering apparatus suitable for depositing the transparent electrode of the photovoltaic element of the present invention, for example, there is a DC magnetron sputtering apparatus schematically shown in FIG.

The DC magnetron sputtering apparatus schematically shown in FIG. 3 suitable for depositing the transparent electrode of the photovoltaic element of the present invention comprises a deposition chamber 301, a substrate 302, and a heater 30.
3, targets 304, 308, insulating support 305,
309, DC power supplies 306 and 310, shutter 307,
311, vacuum gauge 312, conductance valve 313,
It is composed of gas introduction valves 314 and 315, mass flow controllers 316 and 317, and the like.

In the DC-magnetron sputtering apparatus, when a transparent electrode composed of a tin oxide layer is deposited on a glass substrate, a target such as metallic tin (Sn) or tin oxide (SnO ₂ ) is used. When metallic tin is used for the target, reactive sputtering may be performed in an oxidizing atmosphere to form the tin oxide layer.

When a transparent electrode made of indium-tin oxide is further deposited on the substrate, the target is metallic tin,
Targets such as metal indium or an alloy of metal tin and metal indium, tin oxide, indium oxide, and indium-tin oxide are appropriately combined and used.

When depositing by the sputtering method, the substrate temperature is an important factor, and 25 ° C. to 600 ° C. is mentioned as a preferable range. In addition, as a gas for sputtering when depositing the transparent electrode by a sputtering method, an inert gas such as argon gas (Ar), neon gas (Ne), xenon gas (Ke), and helium gas (He) can be mentioned, and Ar is particularly preferable. Gas is the best choice. Further, it is preferable to add oxygen gas (O ₂ ) to the inert gas as needed. Especially when a metal is used as a target, oxygen gas (0 ₂ ) is essential.

Further, when the target is sputtered with the above-mentioned inert gas or the like, the pressure of the discharge space is 0.1 to 50 mTorr in order to perform the sputtering effectively.
Is mentioned as a preferable range.

In addition, a DC power supply or an RF power supply is suitable as a power supply for the sputtering method. 10-1000W as electric power at the time of sputtering
Is a suitable range.

The deposition rate of the transparent electrode depends on the pressure in the discharge space and the discharge power, and the optimum deposition rate is 0.1.
The range is from 100 Å / sec.

In the photovoltaic element of the present invention, it is preferable that the transparent electrode is deposited under the condition that the antireflection film is satisfied. As a specific layer thickness of the transparent electrode, 500 Å to 3000 Å is mentioned as a preferable range.

As a second method suitable for depositing the transparent electrode of the photovoltaic device of the present invention, there is a vacuum vapor deposition method.

The vacuum vapor deposition apparatus is, as schematically shown in FIG. 5, a deposition chamber 501, a substrate 502, a heater 503,
The vapor deposition source 504, the conductance valve 509, the gas introduction valve 510 and the like are included.

Suitable vapor deposition sources for depositing transparent electrodes in the vacuum vapor deposition method include metal tin, metal indium, and indium-tin alloy.

Further, the temperature of the glass substrate when depositing the transparent electrode is preferably in the range of 25 ° C to 600 ° C.

Further, when depositing the transparent electrode, the pressure in the deposition chamber is reduced to 10 ⁻⁶ Torr or less and then oxygen gas (O ₂ ) is added.
Is preferably introduced into the deposition chamber in the range of 5 × l0 ^over 5 Torr~9 × l0 ^over 4 Torr.

By introducing oxygen in this range, the metal vaporized from the vapor deposition source reacts with oxygen in the vapor phase to deposit a good transparent electrode.

Further, RF power may be introduced at the above-mentioned degree of vacuum to generate plasma, and vapor deposition may be performed through the plasma.

The preferable range of the deposition rate of the transparent electrode under the above conditions is 0. 1 to 100Å / sec. The deposition rate is 0. If it is less than lÅ / sec, the productivity will decrease, and if it is more than 100Å / sec, a rough film will be formed, and the transmittance, the conductivity, and the writing quality will decrease.

(P-type layer, n-type layer) In the photovoltaic element of the present invention, the p-type layer and the n-type layer are important layers that influence the characteristics of the photovoltaic element.

The p-type layer or n-type layer of the photovoltaic element of the present invention is made of a non-single crystalline silicon semiconductor. Examples of the non-single-crystal material include an amorphous material (designated as "a-") or a polycrystalline material (designated as "poly-"). Needless to say, the microcrystalline material (indicated as “μc−”) also falls into the category of amorphous materials. As the amorphous material, for example, a-Si: H, a-Si: HX,
a-SiC: H, a-SiC: HX, a-SiGe:
H, a-SiGeC: H, a-SiO: H, a-Si
N: H, a-SiON: HX, a-SiOCN: HX,
μC-Si: H, μe-SiC: H, μC-Si: H
X, μC-S-C: HX, μC-SiGe: H, μC-
SiO: H, μc-SiGeC: H, μc-SiN:
H, μC-SiON: HX, μc-SiOCN: HX, etc., and a p-type valence electron control agent (group III atoms B and A of the periodic table).
1, Ga, In, Tl) and n-type valence electron control agents (group V atoms P, Al, Sb, Bi of the periodic table) are added at a high concentration.

As the polycrystalline material, for example, po1y-S is used.
i: H, poly-Si: HX, poly-SiC;
H, poly-SiC: HX, poly-SlGe:
H, poly-Si, poly-S1C, po1y-S
lGe, etc., a p-type valence electron control agent (group III atoms B, Al, Ga, In, Tl of the periodic table) and an n-type valence electron control agent (group V atoms P, As, Sb of the periodic table). , Bi) is added to the material at high concentration.

Particularly, in the p-type layer or the n-type layer on the light incident side,
A crystalline semiconductor layer with little light absorption or an amorphous semiconductor layer with a wide band gap is suitable.

Here, 0.1-50 at% is an optimum amount for the addition amount of the group III atom of the periodic table to the p-type layer and the addition amount of the group V atom of the periodic table to the n-type layer. Be done.

The hydrogen atoms (H, D) or halogen atoms contained in the p-type layer or the n-type layer are the p-type layer or the n-type layer.
It serves to compensate dangling bonds of the mold layer and improves the doping efficiency of the p-type layer or the n-type layer. The optimum amount of hydrogen atoms or halogen atoms added to the p-type layer or the n-type layer is 0.1 to 40 at%. Especially p
When the type layer or the n-type layer is crystalline, the optimum amount of hydrogen atoms or halogen atoms is 0.1 to 8 at%. Further, a preferable distribution form is one in which the content of hydrogen atoms and / or halogen atoms is largely distributed on the interface side of each of the p-type layer / i-type layer and the n-type layer / i-type layer. The content of hydrogen atoms and / or halogen atoms is preferably in the range of 1.1 to 2 times the content in the bulk. Thus, by increasing the content of hydrogen atoms or halogen atoms in the vicinity of each interface of the p-type layer / i-type layer and the n-type layer / i-type layer, the defect level and mechanical strain near the interface are reduced. It is possible to increase the photovoltaic power and the photocurrent of the photovoltaic device of the present invention.

Further, transparent electrode / p-type layer or transparent electrode /
A preferred distribution form is one in which a large amount of hydrogen atoms and / or halogen atoms are distributed on each interface side of the n-type layer, and the content of hydrogen atoms and / or halogen atoms near the interface is bulk. The preferable range is 1.1 to 2 times the content of the above. Thus, by increasing the content of hydrogen atoms or halogen atoms in the vicinity of each of the transparent electrode / p-type layer or the transparent electrode / i-type interface, it is possible to reduce the defect level and mechanical strain in the vicinity of the interface. Therefore, the photovoltaic power and the photocurrent of the photovoltaic device of the present invention can be increased.

Regarding the electrical characteristics of the p-type layer and the n-type layer of the photovoltaic element of the present invention, the activation energy is preferably 0.2 eV or less, and most preferably 0.1 eV or less. The specific resistance is preferably 100 Ωcm or less,
The optimum value is lΩcm or less. Furthermore, the layer thickness of the p-type layer and the n-type layer is preferably 10 to 500Å, and most preferably 30 to 100Å.

Suitable source gases for depositing the p-type layer or the n-type layer of the photovoltaic element of the present invention include a silicon atom-containing gasifiable compound, a germanium atom-containing gasifiable compound, and a nitrogen atom. It is possible to form a gasifiable compound containing the above and a mixed gas of the compound.

Specific examples of the gasifiable compounds containing silicon atoms include SiH ₄ , SiH ₆ , SiF ₄ , and Si.
FH ₃ , SiF ₂ H ₂ , SiF ₃ H, Si ₃ H ₃ , SiD ₄ ,
SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, SiFD ₃ , Si
_{F 2 D 2, SiD 3 H} , etc. Si ₂ D ₃ H _3, and the like.

Specific examples of the gasifiable compound containing a germanium atom include GeH ₄ , GeD ₄ , GeF ₄ ,
GeFH ₃ , GeF ₂ H ₂ , GeF ₃ H, GeHD ₃ , Ge
_{H 2 D 2, GeH 3 D} , GeH 6, GeD 6 , and the like.

Specific examples of the gasifiable compound containing a carbon atom include CH ₄ , CD ₄ , and C _n H _{2n + 2} (n is an integer).
C _n H _{2n (n} is an _{integer), C 2 H 2, C} 6 H 6, CO 2, CO , and the like.

As the nitrogen-containing gas, N ₂ , NH ₃ , ND
₃ , NO, NO ₂ , N ₂ O can be mentioned.

Oxygen-containing gas includes O ₂ , CO, CO ₂ ,
_{NO, NO 2, N 2 O} , CH 3 CH 2 OH, CH 3 OH , and the like.

Examples of the substance introduced into the p-type layer or the n-type layer for controlling the valence electrons in the present invention include Group III atoms and Group V atoms of the periodic table.

What is effectively used as a starting material for introducing a Group III atom in the present invention is specifically B ₂ H ₆ , B ₄ H ₁₀ , B for introducing a boron atom.
_{5 H 9, B 5 H 11} , B 6 H 10, B 5 H 12, B 6 H 14 , etc. borohydride, may be mentioned BF _3, BC boron halide such as _l3. AlC _l3, GaCl ₃ In addition to this, I
nC _{l 3,} TlC _l3, and the like can also be mentioned. Especially B
_{In the} present invention in which ₂ H ₆ and BF ₃ are suitable, the starting materials for introducing the group V atom are effectively used, specifically, for introducing the phosphorus atom, PH ₃ , P ₂ H _4, etc. Phosphorus hydride, PH ₄ I, PF ₃ , PF ₅ , PCl ₃ , PCl ₅ , PB
Examples thereof include phosphorus halides such as r ₃ , PBr ₃ and PI ₃ . In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsB
r ₃ , AsF ₅ , SbH ₃ , SbF ₃ , SbF ₅ , SbC
Other examples include l ₃ , SbCl ₃ , BiH ₃ , BiCl ₃ and BiBr ₃ . Particularly, PH ₃ and PF ₃ are suitable.

As a method of depositing the p-type layer or the n-type layer suitable for the photovoltaic element of the present invention, for example, RF plasma CV is used.
D method and microwave (abbreviated as "μw") plasma CV
There is D method.

Particularly, when the deposition is performed by the RF plasma CVD method, the capacitive coupling type RF plasma CVD method is suitable.

A p-type layer or n is formed by the RF plasma CVD method.
When depositing the mold layer, the substrate temperature in the deposition chamber is 100-
350 ° C., internal pressure 0.1 to 10 Torr, RF power 0.05 to 1.0 W / cm ² , deposition rate 0.1.
An optimum condition is ~ 30Å / sec.

Further, the gasifiable compound is replaced by H ₂ , H
It may be appropriately diluted with a gas such as e, Ne, Ar, Xe, or Kr and introduced into the deposition chamber.

In particular, when depositing a layer having a small band of light absorption or a wide bandgap such as a microcrystalline semiconductor or a-SiC: H, the source gas is diluted 2 to 100 times with hydrogen gas and the RF power is relatively high. It is preferable to introduce power. As the RF frequency, 1 MHz to 100 MHz is a suitable range, and a frequency near 13.56 MHz is particularly suitable.

The p-type layer or the n-type layer suitable for the present invention is μw
When depositing by plasma CVD method, μw plasma CVD
The device has a dielectric window (alumino-ceramics etc.) in the deposition chamber.
A method of introducing microwaves through a waveguide via a is suitable.

The p-type layer or the n-type layer suitable for the present invention is μw
When depositing by the plasma CVD method, the substrate temperature in the deposition chamber is 100 to 400 ° C., and the internal pressure is 0.5 to 30 mTorr.
The preferable ranges of r and μW power are 0.01 to 1 W / cm ² , and the frequency of μw is 0.5 to 10 GHz.

Further, the gasifiable compound is replaced by H ₂ , H
It may be appropriately diluted with a gas such as e, Ne, Ar, Xe, or Kr and introduced into the deposition chamber.

Particularly when depositing a layer having a small band of light absorption or a wide band gap, such as a microcrystalline semiconductor or a-SiC: H, the source gas is diluted 2 to 100 times with hydrogen gas, and the μw power is relatively high. It is preferable to introduce power.

(I-Type Layer) In the photovoltaic device of the present invention, the i-type layer is an important layer for generating and transporting carriers for irradiation light.

As the i-type layer of the photovoltaic element of the present invention,
A p-type layer and a p-type layer can also be used. When a semiconductor layer in which the hole mobility and lifetime product are smaller than the electron mobility and lifetime product is used as the i-type layer, a slightly p-type layer is suitable. When a semiconductor layer whose electron mobility and lifetime product is smaller than hole mobility and lifetime product is used as the i-type layer, only n
Mold layers are suitable.

The i-type layer of the photovoltaic element of the present invention is made of an amorphous material (denoted as "ai"), for example, a-Si:
H, a-Si: HX, a-SiC: H, a-SiC: H
X, a-SiGe: H, a-SiGe: HX, a-Si
GeC: HX etc. are mentioned.

In particular, for the i-type layer, an intrinsic material is prepared by adding a group III atom and / or a group V atom of the periodic table to the above amorphous material as a valence electron control agent.
The materials mentioned in c) are mentioned as suitable ones.

The hydrogen atom (H, D) or the halogen atom (X) contained in the i-type layer serves to compensate dangling bonds in the i-type layer, and the mobility and life of the carrier in the i-type layer. To improve the product of P-type layer / i-type layer, n-type layer /
It has a function of compensating the interface state of each interface of the i-type layer, and has an effect of improving the photovoltaic power, the photocurrent and the photoresponsiveness of the photovoltaic device. The optimum content of hydrogen atoms and / or halogen atoms contained in the i-type layer is 1 to 40 at%. In particular, p-type layer / i-type layer, n-type layer /
A preferable distribution form is one in which the content of hydrogen atoms and / or halogen atoms is largely distributed on each interface side of the i-type layer, and the content of hydrogen atoms and / or halogen atoms in the vicinity of the interface is bulk. Of the content of The preferable range is 1 to 2 times.

The layer thickness of the i-type layer largely depends on the structure of the photovoltaic element (for example, single cell, tandem cell, triple cell) and the band gap of the i-type layer, but is 0.1-1.
The optimum layer thickness is 0 μm.

The basic physical properties of the i-type layer are 0.01 cm ² / electron mobility in order to effectively achieve the object of the present invention.
V / sec or more, hole mobility is 0.0001 cm ² /
V / sec or more, bandgap is 1.1 to 2.2e
V, the localized density at the center of the forbidden band is 10 ¹³ / cm ³ / eV or less, and the inclination of the Arbach tail on the valence band side is 65 meV
The following are preferable ranges. In addition, the photovoltaic element of the present invention is used as AMl. It is desirable that the current-voltage characteristic is measured under 5, 100 mW / cm ² and Carp fitting is performed by the Hecht formula, and the mobility life product obtained from this Carp fitting is 10 ⁻¹⁰ cm ² / V or more. ..

The band gap of the i-type layer is p-type layer /
It is preferable that the i-type layer and the n-type layer / i-type layer are designed so as to be wide on each interface side. By designing in this way, the photovoltaic power and photocurrent of the photovoltaic element can be increased, and further photodegradation and the like can be prevented when used for a long time.

As a source gas suitable for depositing the i-type layer of the photovoltaic element of the present invention, a gasifiable compound containing a silicon atom, a gasifiable compound containing a germanium atom, a gas containing a carbon atom Compounds, etc.
And a mixed gas of the compound.

Specific examples of the gasifiable compound containing silicon atoms include SiH ₄ , SiH ₆ , SiF ₄ , and Si.
FH ₃ , SiF ₂ H ₂ , SiF ₃ H, Si ₃ H ₃ , SiD ₄ ,
SiHD ₃ , SiH ₂ D ₂ , SiH ₃ D, SiFD ₃ , Si
_{F 2 D 2, SiD 3 H} , etc. Si ₂ D ₃ H _3, and the like.

Specifically, a gas containing germanium atoms
GeH is a compound that can be converted into_Four, GeD_Four, GeF_Four，
GeFH₃, GeF₂H₂, GeF₃H, GeHD₃, Ge
H₂D ₂, GeH₃D, GeH₆, GeD₆Etc.
It

Specific examples of the gasifiable compound containing a carbon atom include CH ₄ , CD ₄ , CR _n H _{2n + 2} (n is an integer), C _n H _2n (n is an integer), C ₂ H ₂ , C ₆ H ₆ and the like. In the present invention, the substance introduced into the i-type layer for controlling the valence electrons of the i-type layer includes Group III atoms and Group V atoms of the periodic table.

In the present invention, those effectively used as a starting material for introducing a Group III atom include B ₂ H ₆ , B ₄ H ₁₀ , B for introducing a boron atom.
_{5 H 9, B 5 H 11} , B 6 H 10, B 6 H 12, B 6 H 14 , etc. borohydride, may be mentioned BF _3, BCl ₃ or the like boron halide or the like. In addition to this, AlCl ₃ , GaCl ₃ ,
InCl ₃ , TlCl _{3 and the} like can also be mentioned.

In the present invention, a starting material for introducing a V-flag atom is effectively used as, specifically, a phosphorus hydride such as PH ₃ or P ₂ H ₄ for introducing a phosphorus atom. PH ₄ I, P
F ₃ , PF ₅ , PCl ₃ , PCl ₅ , PBr ₃ , PBr ₅ , P
Examples thereof include phosphorus halides such as I ₃ . In addition, AsH ₃ ,
AsF ₅ , AsCl ₃ , AsBr ₃ , AsF ₅ , SbH ₃ ,
SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ ,
BiCl ₃ , BiBr _{3 and the} like can also be mentioned.

Periodic table introduced to control the conduction type in the i-type layer. The introduced amount of group III atoms and group V atoms is 10.
A preferred range is 00 ppm or less.

Examples of the i-type layer deposition method suitable for the present invention include RF plasma CVD method and μw plasma CVD method. In the case of the RF plasma CVD method, a capacitively coupled RF plasma CVD apparatus is particularly suitable.

When depositing the i-type layer by the RF plasma CVD method, the substrate temperature in the deposition chamber is 100 to 350 ° C., the internal pressure is 0.1 to 10 torr, and the RF power is 0.05 to.
1.0 W / cm ² , deposition rate 0.1-30 Å / sec
Is the optimum condition.

Further, the compound capable of being gasified is replaced by H ₂ , H
It may be appropriately diluted with a gas such as e, Ne, Ar, Xe or Kr and introduced into the deposition chamber.

In particular, when depositing a layer having a wide band gap such as a-SiC: H, it is preferable to dilute the source gas 2 to 100 times with hydrogen gas and introduce a relatively high RF power. is there. If the frequency of RF is 1M
Hz to 100 MHz is a suitable range, especially 13.5.
The optimum frequency is around 6 MHz.

An i-type layer suitable for the present invention is provided with a μw plasma CV.
In the case of depositing by the D method, the μw plasma CVD apparatus is preferably a method in which a microwave is introduced into the deposition chamber through a dielectric window (aluminoceramic or the like) by a waveguide.

An i-type layer suitable for the present invention is provided with a μw plasma CV.
When depositing by the D method, the substrate temperature in the deposition chamber is 100 to
400 ° C., internal pressure 0.5 to 30 mtorr, μw power 0.01 W to 1 W / cm ² , μw frequency 0.5 to
10 GHz is mentioned as a preferable range.

Further, the gasifiable compound is replaced by H ₂ , H
It may be appropriately diluted with a gas such as e, Ne, Ar, Xe, or Kr and introduced into the deposition chamber.

In particular, when a wide bandgap layer such as a-SiC: H is deposited, it is preferable to dilute the source gas 2 to 100 times with hydrogen gas and to introduce a relatively high power for μw power. is there.

(Reflection Increasing Layer) In the photovoltaic element of the present invention, the reflection increasing layer is made of ZnO, SnO ₂ , In ₂ O ₃ ,
ITO, TiO ₂ , CdO, Cd ₂ SnO ₄ , Bi ₂ O ₃ ,
MoO ₃ , Na _x WO ₃ , etc. are mentioned as the optimum ones.

Suitable methods for depositing the reflection-increasing layer include vacuum vapor deposition method, sputtering method, CVD method, spray method, spin-on method, dip method and the like.

The layer thickness of the reflection increasing layer varies depending on the refractive index of the material of the reflection increasing layer, but a preferable range of the layer thickness is 500 Å to 10 μm.

(Conductive Layer and Protective Layer) The conductive layer may be entirely made of a conductive material, or an insulating layer may be formed on the layer. As the conductive material, for example, NiCr, stainless steel, Al, Cr, Mo, Au,
Examples include metals such as Nb, Ta, V, Ti, Pt, Pb, and Sn, or alloys thereof. Vacuum deposition of the metal,
It may be formed as a thin film by a sputtering method or the like. Examples of the electrically insulating material include polyester, polyethylene, polycarbonate, cellulose acetate,
Examples thereof include synthetic resins such as polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene and polyamide, and films or sheets made of glass, ceramics, paper and the like. It is preferable that at least one surface of these layers made of an electrically insulating material is coated with an adhesive to adhere it to the metal thin film layer.

The electrically insulating material can be made as thin as possible within the range where the function as the protective layer is sufficiently exhibited.
However, in view of manufacturing and handling, mechanical strength and the like are usually 10 μm or more.

[0097]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 A photovoltaic element was manufactured by the vacuum deposition method, the DC magnetron sputtering method and the μW glow discharge decomposition method as described below.

First, a glass substrate made of a glass support containing tin (Sn) atoms distributed therein was prepared by the following procedure using the vacuum vapor deposition apparatus shown in FIG.

In the figure, 302 is a glass support, which is 50 m
It is made of barium borosilicate glass (7059 manufactured by Corning Co., Ltd.) having an m-square and a thickness of 1 mm.

Reference numeral 304 in the figure denotes an evaporation source having a composition of tin (Sn) atoms.

In the figure, reference numerals 310 and 312 denote gas introduction valves, which are connected to an O ₂ gas cylinder and an Ar gas cylinder (not shown), respectively.

First, the glass support 302 was heated to 400 ° C. by the heater 303, the inside of the deposition chamber 301 was evacuated by a vacuum pump (not shown), and the reading of the vacuum gauge 308 reached about 1 × 10 ⁻⁵ Torr. At this point, gas introduction valve 3
10 was gradually opened to allow O ₂ gas to flow into the deposition chamber 301. At this time, the mass flow controller 311 was used to adjust the O ₂ gas flow rate to 10 sccm, and the deposition chamber 3
The opening of the conductance valve (butterfly type) 309 was adjusted while observing the vacuum gauge 308 so that the pressure inside 01 became 0.3 mTorr.

After that, electric power is supplied to the heater 305 from the AC power source 306 to heat the vapor deposition source 304, and then,
The shutter 307 is opened to start the formation of tin oxide on the glass support 302, and when the tin oxide having a layer thickness of 10 nm is formed, the shutter 307 is closed and the AC power source 30
The output of 6 was turned off, the gas introduction valve 310 was closed, and the gas inflow into the deposition chamber 301 was stopped.

Next, the gas introduction valve 312 is gradually opened to allow Ar gas to flow into the deposition chamber 301, and the Ar flow rate is adjusted to 10 sccm by the mass flow controller 313, and the pressure in the deposition chamber 301 is adjusted to 1 Torr. The conductance valve (butterfly type) 309 opening was adjusted while observing the vacuum gauge 308. next,
The glass support 302 is heated to 700 by the heater 303.
The glass support 302 was heated to 0 ° C. and heat-treated for 2 hours to complete the production of the glass support 302 containing tin atoms distributed therein.

Next, a transparent electrode was formed on the glass support by using the DC magnetron sputtering method manufacturing apparatus shown in FIG.

In the figure, reference numeral 402 denotes a glass support containing tin atoms distributed therein.

In the figure, 404 has a composition of tin (Sn).
And is insulated from the deposition chamber 401 by an insulating support 405.

In the figure, reference numerals 410 and 412 are gas introduction valves, which are connected to an oxygen (O ₂ ) gas cylinder and an argon (Ar) gas cylinder, respectively, which are not shown.

Further, a glass heater is supported by the heater 403.
The holder 402 is heated to 350 ° C., and the inside of the deposition chamber 401 is not illustrated.
Evacuate with the vacuum pump shown, and read the vacuum gauge 408
1 x 10^-Five When it becomes Torr, the gas introduction valve 4
Open 10 and 412 gradually to open O₂Gas, Ar gas deposited
It was made to flow into the chamber 401. At this time, O₂Gas flow rate is 20
sccm, Ar gas flow rate to be 20 sccm,
Adjust with each mass flow controller 411, 413
So that the pressure in the deposition chamber 401 becomes 2 mTorr.
While watching the vacuum gauge 408, conductance valve (
The opening of the (tutter type) 409 was adjusted. Then DC power
The voltage of the source 406 is set to -400V and the target 4
04, DC power is introduced, and then the shutter 407 is opened.
Then, the production of the transparent electrode on the glass support 402 is started.
And a transparent electrode with a layer thickness of 70 nm was made
The DC power supply 406 output,
The glow discharge was stopped. Next, the gas introduction valve 412 is closed.
Then, the flow of Ar gas into the deposition chamber 40l is stopped and the deposition is stopped.
The pressure in the chamber 401 becomes 1 Torr,
Adjust the opening of the closet valve 409 to make the transparent electrode for 1 hour.
Was heat treated to complete the production of the transparent electrode.

Next, the source gas supply device 102 shown in FIG.
A non-single-crystal silicon-based semiconductor layer was formed on the transparent electrode by a manufacturing apparatus by the μW glow discharge decomposition method including 0 and a deposition apparatus 1000.

The gas cylinders 1071 to 1076 in the figure are sealed with a source gas for producing the non-single-crystal silicon semiconductor layer of the present invention, and 1071 is a SiH ₄ gas (purity 99.999%) cylinder. , 1072 is a cylinder of H ₂ gas (purity 99.9999%), 1073 is B ₂ H ₆ gas (purity 99.99%, diluted to 10% with H ₂ gas,
Hereinafter, abbreviated as "B ₂ H ₆ / H ₂ ") cylinder, 1074 is PH ₃ gas diluted to 10% with H ₂ gas (purity 99.9).
9%, hereinafter abbreviated as "PH ₃ / H ₂ ") cylinder, 107
5 is a CH ₄ gas (purity 99.9999%) cylinder, 10
76 is a GeH ₄ gas (purity 99.99%) cylinder. Also, in advance, gas cylinders 1071 to 1076
When installing the respective gas,
It is introduced from 056 into the gas pipe of the inflow valves 1031 to 1036.

In the figure, 1004 is a glass support on which a transparent electrode is produced by the method described above. First, SiH ₄ gas from the gas cylinder 1071 and H ₂ from the gas cylinder 1072.
Gas, gas cylinder 1073 to B ₂ H ₆ / H ₂ gas, gas cylinder 1074 to PH ₃ / H ₂ gas, gas cylinder 107
CH ₄ gas from No. 5 and GeH ₄ gas from gas cylinder 1076 are introduced by opening valves 1051 to 1056, and each gas pressure is adjusted to about 2 kg / by using pressure regulators 1061 to 1066.
It was adjusted to cm ² .

Next, it is confirmed that the inflow valves 1031 to 1036 and the leak valve 1009 of the deposition chamber 1001 are closed, and the outflow valves 1041 to 1046,
After confirming that the auxiliary valve 1008 is opened, the conductance (butterfly type) valve 1007 is fully opened, and the deposition chamber 1001 and the gas pipe are evacuated by a vacuum pump (not shown). 1 x 10
At the time of ^-4 Torr, the auxiliary valve 1008 and the outflow valves 1041 to 1046 were closed.

Next, the inflow valves 1031 to 1036 are gradually opened to let each gas flow through the mass flow controller 1.
021-1026.

After the preparation for film formation was completed as described above, a p-type layer, an i-type layer and an n-type layer were formed on the glass substrate 1004.

To prepare the p-type layer, the glass substrate 100 is used.
4 is heated to 350 ° C. by the heater 1005, the outflow valves 1041 to 1043 are gradually opened, and SiH ₄
Gas, H ₂ gas, B ₂ H ₆ / H ₂ gas into the gas introduction pipe 1003
Flow into the deposition chamber 1001. At this time, Si
H ₄ gas flow rate is 10 sccm, H ₂ gas flow rate is 100 sccm
cm, and the B ₂ H ₆ / H ₂ gas flow rate was adjusted to 5 sccm by each mass flow controller 1021 to 1023. The pressure in the deposition chamber 1001 is 20 mTorr
The opening of the conductance valve 1007 was adjusted while observing the vacuum gauge 1006 so that After that, μ (not shown)
The power of the W power source was set to 400 mW / cm ³ , and μW power was introduced into the deposition chamber 1001 through a waveguide, a waveguide section 1010, and a dielectric window 1002 (not shown) to cause a μW glow discharge, and a transparent electrode. The production of the p-type layer was started thereon, and when the p-type layer having a layer thickness of 5 nm was produced, the μW glow discharge was stopped, and the outflow valves 1041 to 1043 and the auxiliary valve 10 were stopped.
08 is closed to stop the gas flow into the deposition chamber 1001.
The production of the p-type layer was completed.

Next, to prepare an i-type layer, a glass substrate
1004 is heated to 350 ° C by heater 1005
The outflow valves 1041 and 1042 and the auxiliary valve 10
08 is opened gradually and SiH_FourGas, H₂Gas introduction
It was made to flow into the deposition chamber 1001 through the pipe 1003. This
When, SiH_FourGas flow rate is 100 sccm, H₂Gas flow
Of each mass flow controller to be 200 sccm
It was adjusted with rollers 1021 and 1022. Deposition chamber 100
The pressure inside 1 is set to 100 m so that the pressure is 5 mTorr.
While watching 6, adjust the opening of conductance valve 1007.
Arranged Next, the high frequency of the bias power supply (hereinafter referred to as "RF")
Bias is 100 mW / cm³ , DC via
Set the voltage to 75V against the glass substrate 1004, and
It was applied to the ass rod 1012. After that, μW power supply (not shown)
Power of 100 mW / cm³Set to the waveguide (not shown)
Deposition through tube, waveguide 1010 and dielectric window 1002
A μW electric power is introduced into the chamber 1001 to generate a μW glow discharge.
And the production of the i-type layer on the p-type layer is started, and the layer thickness 400
Stop the μW glow discharge when the i-type layer of nm is produced.
Hey, turn off the output of bias power supply 1011 and make an i-type layer.
Finished.

To prepare an n-type layer, a glass substrate 100
4 was heated to 300 ° C. by the heater 1005, the outflow valve 1044 was gradually opened, and SiH ₄ gas, H ₂ gas, and PH ₃ / H ₂ gas were caused to flow into the deposition chamber 1001 through the gas introduction pipe 1003. At this time, the SiH ₄ gas flow rate is 30 sccm, the H ₂ gas flow rate is 100 sccm, and the PH ₃
/ H ₂ gas flow rate was adjusted to 6 sccm by each mass flow controller 1021, 1022, 1024. The pressure inside the deposition chamber 1001 was adjusted to 10 mTorr by adjusting the opening of the conductance valve 1007 while observing the vacuum gauge 1006. After that, μW not shown
The power of the power supply is set to 50 mW / cm ³ , and μW power is introduced into the deposition chamber 1001 through a waveguide, a waveguide section 1010 and a dielectric window 1002 (not shown) to cause μW glow discharge, and the i-type layer. Starting the production of the n-type layer on top, the layer thickness is 10n
When the n-type layer of m was produced, the μW glow discharge was stopped,
The outflow valves 1041, 1042, 1044 and the auxiliary valve 1008 were closed to stop the gas inflow into the deposition chamber 1001 to complete the production of the n-type layer.

It is needless to say that the outflow valves 1041 to 1046 other than the required gas are completely closed when each layer is formed, and the outflow valve 1041 flows out of each gas in the deposition chamber 1001. -1046 to the deposition chamber 1001 in order to avoid remaining in the pipe, the outflow valves 1041 to 1046 are closed and the auxiliary valve 1008 is opened.
When 7 was fully opened, the system was once evacuated to a high vacuum, and the operation was repeated as needed.

Next, on the n-type layer, as a back electrode, Al
Was vacuum-deposited to a thickness of 2 μm to manufacture a photovoltaic device (Device No. Ex 1).

Table 1 shows the manufacturing conditions of the above photovoltaic element.

[0123]

[Table 1 (1)]

[0124]

[Table 1 (Part 2)] (Comparative Example 1) On a support made of barium borosilicate glass (7059 manufactured by Corning Co., Ltd.) similar to that used in Example 1, the same manufacturing conditions as in Example 1 were applied using a DC magnetron sputtering method manufacturing apparatus shown in FIG. Create a transparent electrode with
Next, p was formed on the transparent electrode under the same production conditions as in Example 1 by the production apparatus by the μW glow discharge decomposition method shown in FIG.
A photovoltaic layer was manufactured by forming a mold layer, an i-type layer, an n-type layer, and a back electrode (element No. ratio 1).

Example 1 (Element No. Ex 1) and Comparative Example 1
The durability characteristics of the photovoltaic device manufactured with (Device No. ratio 1) were measured.

The durability characteristics were measured in Example 1 (element No.
The photovoltaic element produced in Example 1) and Comparative Example 1 (element No. ratio 1) was left in a dark place at a temperature of 50 ° C. and a humidity of 85%,
24 ultraviolet rays of about 320 nm (about 200 μW / cm ² )
After irradiating for a period of time, the photovoltaic element was changed to AM-1.5 (1
00 mW / cm ² ) It was installed under light irradiation, and the measurement was performed by the short circuit current, open circuit voltage and fill factor obtained by measuring the VI characteristics. As a result of the measurement, Comparative Example 1 (element N
o. Example 1 (element N) for the photovoltaic element of ratio 1)
o. The photovoltaic element of Example 1) was excellent in short-circuit current 1.05 times, in open circuit voltage 1.03 times, and in fill factor 1.04 times.

The distribution of tin atoms in the glass support of the photovoltaic element of Example 1 (Element No. Ex. 1) was 2%.
Secondary ion mass analyzer (IMS-3F made by CAMECA)
It was confirmed that the content of tin atoms decreased exponentially from the transparent electrode side to the inside of the glass support.

From the above measurement results, the photovoltaic element (element No. 1) using the glass support of the present invention in which tin atoms are distributed and contained is the same as the conventional photovoltaic element (element N).
o. It was found to have excellent characteristics with respect to the ratio 1), and the effect of the present invention was verified.

Example 2 A support made of aluminosilicate glass (Corning Corp. 0317) was used at 800 ° C.
On the glass support under the same production conditions as in Example 1, except that the glass support containing tin atoms in a distributed manner was produced by heat treatment for 4 hours in a transparent electrode, a p-type layer, an i-type layer, and an n-type layer. Mold layer,
A back electrode was produced to produce a photovoltaic element (element N
o. 2).

Comparative Example 2 A support made of aluminosilicate glass (0317 manufactured by Corning Co., Ltd.) was used, except that a support was used.
Under the same production conditions as in Comparative Example 1, a transparent electrode, a p-type layer, an i-type layer, an n-type layer and a back electrode were produced on a glass support to produce a photovoltaic element (element No. ratio 2). .. The durability characteristics of the photovoltaic elements manufactured in Example 2 (element No. Ex 2) and Comparative Example 2 (element No. ratio 2) were measured by the same method as in Example 1. As a result of the measurement, Comparative Example 2 (element N
o. Example 2 (element N) for the photovoltaic element of ratio 2)
o. The photovoltaic element of Example 2) had excellent short-circuit current of 1.06 times, excellent open-circuit voltage of 1.03 times, and excellent fill factor of 1.03 times.

The distribution of tin atoms in the glass support of the photovoltaic element of Example 2 (element No. Ex. 2) was 2%.
Secondary ion mass analyzer (IMS-3F made by CAMECA)
As a result, it was confirmed that the content of tin atoms decreased exponentially from the transparent electrode side to the glass support.

From the above measurement results, the photovoltaic element (element No. Ex. 2) using the glass support containing tin atoms distributed according to the present invention was confirmed to be a conventional photovoltaic element (element N).
o. It was found to have excellent characteristics with respect to the ratio 2), demonstrating the effect of the present invention.

(Example 3) Under the same manufacturing conditions as in Example 1 except that a quartz glass support was used and a glass support containing tin atoms was prepared by heat treatment at 1400 ° C for 10 hours. , A transparent electrode, a p-type layer, on a glass support,
The i-type layer, the n-type layer, and the back electrode were produced to produce a photovoltaic element (Element No. Ex 3).

Comparative Example 3 A transparent electrode, a p-type layer, an i-type layer and an n-type layer were formed on a glass support under the same manufacturing conditions as in Comparative Example 1 except that a support made of quartz glass was used. A back electrode was manufactured to manufacture a photovoltaic device (device No. ratio 3).

Example 3 (Element No. Ex 3) and Comparative Example 3
Durability characteristics of the photovoltaic element manufactured with (Element No. ratio 3) were measured by the same method as in Example 1. As a result of the measurement, in comparison with the photovoltaic element of Comparative Example 3 (element No. ratio 3), the photovoltaic element of Example 3 (element No. Ex 3) was
The short-circuit current is 1.05 times better, the open-circuit voltage is 1.02 times better, and the fill factor is 1. 05 times better.

The distribution of tin atoms in the glass support of the photovoltaic element of Example 3 (Element No. Ex 3) was 2%.
Secondary ion mass analyzer (IMS-3F made by CAMECA)
As a result, it was confirmed that the content of tin atoms decreased exponentially from the transparent electrode side to the glass support.

From the above measurement results, the photovoltaic element (element No. 3) using the glass support of the present invention in which tin atoms are distributed and contained is the same as the conventional photovoltaic element (element N).
o. It was found to have excellent characteristics with respect to the ratio 3), demonstrating the effect of the present invention.

Example 4 A glass support, a transparent electrode, an n-type layer were prepared under the same preparation conditions as in Example 1 except that the n-type layer, i-type layer and p-type layer were prepared as shown in Table 2. , I-type layer, p
A mold layer and a back electrode were prepared to prepare a photovoltaic device (Device No. Ex 4).

[0139]

[Table 2] (Comparative Example 4) A transparent electrode, an n-type layer, an i-type layer, a p-type layer and a back surface were formed on a glass support under the same production conditions as in Example 4 except that the same glass support as in Comparative Example 1 was used. Electrodes were produced to produce photovoltaic devices (device No. ratio 4).

Example 4 (Element No. Ex 4) and Comparative Example 4
The durability characteristics of the photovoltaic element manufactured with (Element No. ratio 4) were measured in the same manner as in Example 1. As a result of the measurement, in contrast to the photovoltaic element of Comparative Example 4 (element No. ratio 4), the photovoltaic element of Example 4 (element No. Ex 4) was
Short-circuit current is 1.05 times better, open-circuit voltage is 1.03 times better, fill factor is 1.04 times better, and a photovoltaic device using the glass support containing tin atoms of the present invention (device). No. Ex 4) was found to have excellent characteristics with respect to the conventional photovoltaic element (element No. ratio 4), and the effect of the present invention was verified.

(Embodiment 5) Under the same manufacturing conditions as in Embodiment 1,
A glass support and a transparent electrode are prepared, and C is placed on the transparent electrode.
After producing a p-type layer, an i-type layer, an n-type layer, a p-type layer, an i-type layer and an n-type layer under the production conditions shown in Table 3 using H ₄ gas and GeH ₄ gas, the n-type layer DC as a reflection increasing layer on the layer
1μ of ZnO thin film by magnetron sputtering method
Then, a silver thin film having a thickness of 300 nm was vapor-deposited as a light reflection layer by a DC magnetron sputtering method, and a back electrode was formed on the silver thin film in the same manner as in Example 1 to prepare a photovoltaic device (device. No. fruit 5).

[0142]

[Table 3] (Comparative Example 5) A transparent electrode, a p-type layer, an i-type layer, an n-type layer, and a p-layer were formed on a glass support under the same production conditions as in Example 5, except that the same glass support as in Comparative Example 1 was used. Type layer, i-type layer, n
A mold layer, a reflection-increasing layer, a light-reflecting layer, and a back electrode were prepared to prepare a photovoltaic device (device No. ratio 5).

Example 5 (Element No. Ex 5) and Comparative Example 5
The durability characteristics of the photovoltaic element manufactured with (Element No. ratio 5) were measured by the same method as in Example 1. As a result of the measurement, the photovoltaic element of Example 5 (element No. Ex. 5) was compared with the photovoltaic element of Comparative Example 5 (element No. ratio 5).
Short-circuit current is 1.05 times better, open-circuit voltage is 1.03 times better, fill factor is 1.05 times better, and a photovoltaic device using the glass support containing tin atoms of the present invention (device). No. Ex. 5) was found to have superior characteristics to the conventional photovoltaic element (element No. ratio 5), and the effect of the present invention was verified.

(Example 6) A glass support containing tin (Sn) atoms in a distributed manner was produced by the same production apparatus as in Example 1 by the vacuum vapor deposition method shown in FIG.

First, the glass support 302 was heated to 400 ° C. by the heater 303, the interior of the deposition chamber 301 was evacuated by a vacuum pump (not shown), and the reading of the vacuum gauge 308 became about 1 × 10 ⁻⁵ Torr. At this point, electric power is supplied from the AC power source 306 to the heater 305 to heat the vapor deposition source 304, and then the shutter 307 is opened to start the production of tin on the glass support 302, and the tin having a layer thickness of 1 nm is used. The shutter 307 is closed when the
The output of 06 was cut off. Next, the gas introduction valve 312 is gradually opened to allow Ar gas to flow into the deposition chamber 301, and Ar gas is introduced.
The gas flow rate is adjusted to 10 sccm with the mass flow controller 313, and the pressure in the deposition chamber 301 is set to 1
The opening of the conductance valve (butterfly type) 309 was adjusted while observing the vacuum gauge 308 so as to be 0 Torr. Next, the glass support 3 is heated by the heater 303.
02 was heated to 600 ° C. and the glass support was heat-treated for 5 hours to complete the production of the glass support 302 containing tin atoms distributed therein.

Next, using the same DC magnetron sputtering method manufacturing apparatus shown in FIG. 4 as in the example, except that a target 404 having a composition of indium (In) and tin (Sn) in a molar ratio of 85:15 was used. A transparent electrode was produced on a glass support under the same production conditions as in Example 1.

Next, under the same manufacturing conditions as in Example 1, a p-type layer, an i-type layer, an n-type layer and a back electrode were formed on the transparent electrode to manufacture a photovoltaic element (element No. 6).

Table 4 shows the manufacturing conditions of the above photovoltaic element.

[0149]

[Table 4 (1)]

[0150]

[Table 4 (Part 2)] (Comparative Example 6) A transparent electrode, a p-type layer, an i-type layer, an n-type layer and a back surface were formed on a glass support under the same production conditions as in Example 6 except that the same glass support as in Comparative Example 1 was used. Electrodes were produced to produce photovoltaic elements (element No. ratio 6).

Example 6 (Element No. Ex 6) and Comparative Example 6
Durability characteristics of the photovoltaic element manufactured in (Element No. ratio 6) were measured by the same method as in Example 1. As a result of the measurement, in comparison with the photovoltaic element of Comparative Example 6 (element No. ratio 6), the photovoltaic element of Example 6 (element No. Ex 6) was
The short circuit current was 1.04 times better, the open circuit voltage was 1.03 times better, and the fill factor was 1.05 times better.

The distribution of tin atoms in the glass support of the photovoltaic element of Example 6 (Element No. Ex. 6) was 2%.
Secondary ion mass analyzer (IMS-3F made by CAMECA)
As a result of the analysis, it was confirmed that the content of tin atoms decreased almost exponentially from the transparent electrode side to the glass support.

From the above measurement results, the photovoltaic element (element No. Ex. 6) using the glass support containing tin atoms distributed according to the present invention was confirmed to be the same as the conventional photovoltaic element (element N).
o. It was found to have excellent characteristics with respect to the ratio 6), demonstrating the effect of the present invention.

Example 7 A photovoltaic element of the present invention was produced by a vacuum vapor deposition method, a DC magnetron sputtering method and a high frequency (hereinafter abbreviated as “RF”) glow discharge decomposition method.

First, under the same manufacturing conditions as in Example 1, a glass support and a transparent electrode containing tin atoms distributed therein were manufactured.

Next, the source gas supply device 102 shown in FIG.
A non-single-crystal silicon-based semiconductor layer was formed on the transparent electrode by a manufacturing apparatus based on the RF glow discharge decomposition method including 0 and a deposition apparatus 1100.

In the figure, 1104 is a glass support on which the above-mentioned transparent electrode is produced.

In the figure, the same raw material gas as in Example 1 was sealed in each of the gas cylinders 1071 to 1076, and each gas was introduced into the mass flow controllers 1021 to 1026 by the same operation procedure as in Example 1. ..

After the preparation for film formation was completed as described above, a p-type layer, an i-type layer and an n-type layer were formed on the glass substrate 1104.

To form the p-type layer, the glass substrate 110 is used.
4 is heated to 300 ° C. by the heater 1105,
The outlet valves 1041 to 1043 and the auxiliary valve 1108
Open gradually, SiH_FourGas, H₂Gas, B₂H₆/ H₂Moth
Gas into the deposition chamber 1101 through the gas introduction pipe 1103.
I put it in. At this time, SiH_FourGas flow rate is 2 sccm, H₂
Gas flow rate is 50 sccm, B₂H₆/ H₂Gas flow rate is 1s
Each mass flow controller 1 to be ccm
It adjusted with 021-1023. Pressure in the deposition chamber 1101
While looking at the vacuum gauge 1106 so that it becomes 1 Torr
The opening of the conductance valve 1107 was adjusted. That
After that, the power of the RF power source (not shown) is set to 200 mW / cm.³ Set up
And set it through the RF matching box 1112.
RF power is introduced to the power supply 1102 to generate RF glow discharge.
Then, the production of the p-type layer on the transparent electrode is started, and the layer thickness is 5 nm.
When the p-type layer was prepared, the RF glow discharge was stopped and the flow
The outlet valves 1041 to 1043 and the auxiliary valve 1108
By closing, the gas flow into the deposition chamber 1101 is stopped and the p-type layer is closed.
Has been completed.

Next, to prepare the i-type layer, a glass substrate
Heat 1104 to 300 ° C with heater 1105
Outflow valves 1041, 1042 and auxiliary valve 11
08 is opened gradually and SiH_FourGas, H₂Gas introduction
It was made to flow into the deposition chamber 1101 through the tube 1103. This
When, SiH_FourGas flow rate is 2 sccm, H₂Gas flow is 2
Each mass flow controller to be 0 sccm
-Adjusted with 1021, 1022. In the deposition chamber 1101
Consider the vacuum gauge 1106 so that the pressure is 1 Torr.
The opening of the glass conductance valve 1107 was adjusted.
After that, the power of the RF power source (not shown) is set to 5 mW / cm.² Set up
And set it through the RF matching box 1112.
RF power is introduced to the power supply 1102 to generate RF glow discharge.
Then, the production of the i-type layer is started on the p-type layer, and the layer thickness is 400 n.
When the i-type layer of m was produced, the RF glow discharge was stopped,
The production of the i-type layer was completed.

Next, in order to form an n-type layer, the glass substrate 1104 is heated to 250 ° C. by the heater 1105, the outflow valve 1044 is gradually opened, and SiH ₄ gas, H ₂ gas, PH ₃ / H is added. _Two gases were caused to flow into the deposition chamber 1101 through the gas introduction pipe 1103. At this time, SiH
₄ gas flow rate is ₂ sccm, H ₂ gas flow rate is 20 sccm,
Each mass flow controller 1021, 1022, 1024 so that the PH ₃ / H ₂ gas flow rate becomes 1 Sccm.
I adjusted it with. The pressure inside the deposition chamber 1101 was adjusted to 1 Torr by adjusting the opening of the conductance valve 1107 while observing the vacuum gauge 1106. After that, RF not shown
The power of the power source was set to 5 mW / cm ³ , RF power was introduced into the cathode 1102 through the RF matching box 1112, RF glow discharge was caused to occur, the n-type layer was formed on the i-type layer, and the layer thickness was 10 nm. When the n-type layer was prepared, the RF glow discharge was stopped and the outflow valve 1041,1
042, 1044 and the auxiliary valve 1108 were closed to stop the gas inflow into the deposition chamber 1101 to complete the production of the n-type layer.

Needless to say, the outflow valves 1041 to 1046 other than the required gas are completely closed when the respective layers are formed, and the respective gases are stored in the deposition chamber 1101 and outflow valve 1041. 1046 to the deposition chamber 1101, in order to avoid remaining in the pipe, the outflow valves 1041 to 1046 are closed, the auxiliary valve 1108 is opened, and the conductance valve 110 is further opened.
When 7 is fully opened, the system is once evacuated to a high vacuum, if necessary.

Then, a back electrode was vapor-deposited on the n-type layer in the same manner as in Example 1 to fabricate a photovoltaic element (element No. Ex. 7).

Table 5 shows the manufacturing conditions of the above photovoltaic element.

[0166]

[Table 5 (1)]

[0167]

[Table 5 (Part 2)] (Comparative Example 7) Except that the same transparent electrode as in Comparative Example 1 was used,
Under the same manufacturing conditions as in Example 7, a p-type layer, i
A photovoltaic layer was fabricated by fabricating the mold layer, the n-type layer, and the back electrode (element No. ratio 7).

Example 7 (Element No. Ex 7) and Comparative Example 7
Photoelectric conversion efficiency and durability characteristics of the photovoltaic element manufactured with (Element No. ratio 7) were measured in the same manner as in Example 1. As a result of the measurement, as compared with the photovoltaic element of Comparative Example 7 (element No. ratio 7), the photovoltaic element of Example 7 (element No. Ex 7) has a short-circuit current of 1.05 times better and opens. If the voltage is l. The photovoltaic element (element No. No. 7) of the present invention using the glass support containing tin atoms distributed therein is a conventional photovoltaic element ( It was found to have excellent characteristics with respect to the device No. ratio 7), and the effect of the present invention was verified.

[0169]

As described above, the photovoltaic element of the present invention improves the adhesion between the glass support and the transparent electrode by incorporating the tin atom constituting the transparent electrode into the glass support. It is possible to prevent the deterioration of the characteristics of the photovoltaic element due to high temperature and high humidity and long-time UV irradiation, and to prevent short circuit of the photovoltaic element due to high temperature and high humidity and long-time UV irradiation. Factors have improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining a layer configuration of a photovoltaic element of the present invention.

FIG. 2 is a schematic configuration diagram for explaining a layer configuration of the photovoltaic element of the present invention.

FIG. 3 is a schematic explanatory view of a manufacturing apparatus by a vacuum vapor deposition method, which is an example of an apparatus for manufacturing a glass support used in the photovoltaic element of the present invention.

FIG. 4 is a schematic explanatory view of a manufacturing apparatus by a DC magnetron sputtering method, which is an example of an apparatus for manufacturing a transparent electrode used in the photovoltaic element of the present invention.

FIG. 5 is a schematic explanatory view of a manufacturing device by a glow discharge method using μW, which is an example of a device for manufacturing a non-single-crystal silicon semiconductor layer used in the photovoltaic element of the present invention.

FIG. 6 is a schematic explanatory view of a manufacturing device by a glow discharge method using RF, which is an example of a device for manufacturing a non-single-crystal silicon semiconductor layer used in the photovoltaic element of the present invention.

[Explanation of symbols]

101 glass support, 102 conductive light reflecting layer, 103 reflection increasing layer, 104 n-type (or p-type) non-single-crystal silicon semiconductor layer, 105 i-type (substantially intrinsic) non-single-crystal silicon Semiconductor layer, 106 p-type (or n-type) non-single-crystal silicon semiconductor layer, 107 transparent electrode, 108 current collecting electrode, 109 irradiation light, 110 conductive layer (and / or protective layer), 201 glass support, 202 Conductive light reflecting layer, 203 reflection increasing layer, 204a, b n-type (or p-type) non-single-crystal silicon semiconductor layer, 205a, 205b i-type (substantially intrinsic) non-single-crystal silicon semiconductor layer 206a, 206b p-type (or n-type) non-single-crystal silicon semiconductor layer, 207 transparent electrode, 208 current collecting electrode, 209 irradiation light, 210 conductive layer (or / and / or Protective layer), 301 deposition chamber, 302 glass support, 303 heating heater, 304 evaporation source, 305 heating heater, 306 AC power supply, 307 shutter, 308 vacuum gauge, 309 conductance valve, 310, 312 gas introduction valve, 311 and 313 Mass flow controller, 401 deposition chamber, 402 glass support, 403 heater, 404 target, 405 insulating support, 406 DC power supply, 407 shutter, 408 vacuum gauge, 409 conductance valve, 410, 412 gas introduction valve, 411, 413 Mass flow controller, 1000 μW glow discharge decomposition method film forming apparatus, 1001 deposition chamber, 1002 dielectric window, 1003 gas introduction tube, 1004 substrate (base), 1005 heating heater, 1006 Vacuum gauge, 1007 conductance valve, 1008 auxiliary valve, 1009 leak valve, 1010 waveguide part, l011 bias power supply, 1012 bias rod, l020 source gas supply device, l021 to 1026 mass flow controller, 1031 to 1036 gas inflow valve, l041 to 1046 Gas outflow valve, 1051 to 1056 Raw material gas cylinder valve, 1061 to 1066 Pressure regulator, 1071 to 1076 Raw material gas cylinder, 1100 RF glow discharge decomposition method film forming apparatus, 1101 deposition chamber, 1102 cathode, 1103 gas introduction tube, 1104 substrate , 1105 heating heater, 1106 vacuum gauge, 1107 conductance valve, 1108 auxiliary valve, 1109 leak valve, 1112 RF matching box ..

Claims (5)

[Claims] 1. A substrate with a transparent electrode, which is formed by forming a transparent electrode formed of at least one layer of a tin oxide layer and an indium-tin oxide layer on a glass support, has a non-single crystalline property. In a photovoltaic element in which at least a p-type layer, an i-type layer, an n-type layer and a conductive layer made of a silicon-based semiconductor are laminated, tin atoms are reduced inward from the surface on which the transparent electrode is formed. Photovoltaic devices, characterized in that they are distributed in the glass support. 2. The tin atoms are distributed in the glass support so as to decrease substantially exponentially from the surface on which the transparent electrode is formed toward the inside. Photovoltaic element. 3. The photovoltaic element according to claim 1, wherein the non-single crystalline silicon semiconductor is an amorphous silicon semiconductor. 4. The photovoltaic element according to claim 1, wherein the non-single-crystal silicon-based semiconductor is a polycrystalline silicon-based semiconductor. 5. After depositing a tin metal layer or a tin oxide layer on a glass support, annealing is performed to diffuse tin atoms in the tin metal layer or the tin oxide layer into the glass support, Then, a transparent electrode is formed by oxidizing the tin metal layer to form a tin oxide layer,
Furthermore, at least a p-type layer, an i-type layer, an n-type layer, and a conductive layer made of a non-single crystalline silicon-based semiconductor are formed, which is a method for manufacturing a photovoltaic element.