JPH09191120A - Method for forming non-single crystal semiconductor thin film - Google Patents

Abstract

(57) [Abstract] [Purpose] The output characteristics of pin type photovoltaic elements, especially Vo
(EN) Provided are a photovoltaic device having improved c and FF, resulting in improved output characteristics, and a photovoltaic device having reduced deterioration and improved reliability. [Structure] The p-type semiconductor layer of a pin-type photovoltaic element is multi-layered, a plurality of independent electrodes and a power source are used, and the potentials of the plurality of cathodes (in the discharge space) when a glow discharge occurs ( Self-bias) At least one of the two polarities of the polarities is 0 V or the self-bias polarity is different so that the effect of ion bombardment can be produced on the necessary interface side. The initial characteristics of the electromotive force element and the reliability in actual use are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing photovoltaic devices such as photovoltaic devices. More specifically, the present invention relates to a method for mass-producing photovoltaic devices such as photovoltaic devices using amorphous silicon or amorphous silicon alloy.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a photovoltaic element,
The following technologies are known. That is, for example, the plasma CVD method is generally widely used for manufacturing a photovoltaic element using a non-single-crystal semiconductor film or the like, and has been commercialized. However, it is basically required that the photovoltaic element has sufficiently high photoelectric conversion efficiency, excellent stability of characteristics, and can be mass-produced. For that purpose, in the production of a photovoltaic element using a non-single crystal semiconductor film, it is necessary to improve electrical, optical, photoconductive or mechanical characteristics and fatigue characteristics or repeated use environment characteristics. At the same time, it is necessary to achieve reproducible mass production by high-speed film formation while increasing the area and making the film thickness and film quality uniform. ing.

By the way, in a power generation method using a photovoltaic element, a form in which unit modules are connected in series or in parallel and unitized to obtain a desired current and voltage is often adopted. The disconnection is required not to cause a short circuit. In addition, it is important that there is no variation in output voltage or output current between the modules. For this reason, it is required that the uniformity of the characteristics of the semiconductor layer itself, which is the largest characteristic determining factor, is secured at least at the stage of manufacturing the unit module. Further, from the viewpoint of facilitating the module design and simplifying the module assembling process, the provision of a semiconductor deposited film having excellent property uniformity over a large area enhances the mass productivity of photovoltaic devices. , Is required to achieve a significant reduction in production costs.

In the photovoltaic element, the semiconductor layer which is an important component thereof has a semiconductor junction such as a so-called pn junction or pin junction. When a thin film semiconductor such as a-Si is used, phosphine (PH ₃ ) and diborane (B ₂
A semiconductor film having a desired conductivity type obtained by H ₆₎ source gas at a silane (SiH ₄ containing an element as a dopant, etc.) are mixed and glow discharge decomposition,
It is known that the above semiconductor junction can be easily achieved by sequentially laminating and manufacturing these semiconductor films on a desired substrate. From this fact, when manufacturing a non-single-crystal semiconductor-based photovoltaic element, an independent film forming chamber for manufacturing each semiconductor layer is provided, and each semiconductor layer is manufactured in the film forming chamber. A method has been proposed. Incidentally, US Pat. No. 4,400,409 discloses roll-to-roll
A continuous plasma CVD apparatus adopting a roll (roll to roll) method is disclosed. According to this device, a plurality of glow discharge regions are provided, and a sufficiently long flexible substrate having a desired width is formed on the substrate while depositing a conductive semiconductor layer required in each of the glow discharge regions. By continuously transporting the substrate in the longitudinal direction, a device having a semiconductor junction can be continuously manufactured. Note that, in this specification, a gas gate is used to prevent a dopant gas used in manufacturing each semiconductor layer from diffusing or mixing into another glow discharge region. Specifically, a means for separating each of the glow discharge regions from each other by a slit-shaped separation passage and causing a flow of a scavenging gas such as Ar or H ₂ to act on the separation passage is adopted. . Therefore, although this method is a method suitable for mass production of semiconductor devices, as described above, in order to popularize a large number of photovoltaic elements, further photoelectric conversion efficiency,
It is desired to improve the property stability and property uniformity and reduce the manufacturing cost.

Particularly, in order to improve the photoelectric conversion efficiency and the characteristic stability, the higher the photoelectric conversion efficiency of each unit module is, the better, and the lower the characteristic deterioration rate is, the more preferable. Moreover,
When the unit modules are connected in series or in parallel to make a unit, the unit module with the minimum current or voltage characteristic among the unit modules constituting the unit is rate-determining and the characteristics of the unit are determined. It is very important not only to improve the average characteristics of the above, but also to reduce the variation in characteristics. Therefore, it is desired to ensure the uniformity of the characteristics of the semiconductor layer itself, which is the largest characteristic determining factor, at the stage of manufacturing the unit module. Further, in order to reduce the manufacturing cost, it is strongly desired to improve the yield by reducing the defects of the semiconductor layer so that the disconnection or short circuit does not occur in each module. Further, the p-type semiconductor layer of the photovoltaic element is often set to a very thin layer thickness of at most several hundred angstroms from the viewpoint of element characteristics. Uniformity, film adhesion, dopant doping efficiency, characteristic uniformity, and reproducibility not only affect the characteristics of the photovoltaic element, but also significantly affect the yield of the photovoltaic element.

Further, in the prior art, for example, in the case of a p-type semiconductor layer which is made in a single structure with a typical discharge vessel structure in which a cathode electrode and an anode electrode are arranged in a parallel plate type, most of the electric power supplied is the cathode electrode. As a result of being consumed in the vicinity, the excitation and decomposition reactions of the material gas become active only in a limited part near the cathode electrode, and the thin film formation rate increases only on the power input side, that is, in the vicinity of the cathode electrode. It was difficult to obtain a high deposition rate of. On the other hand, when the power input power is increased in order to obtain a high deposition rate, the temperature of the film forming container or the like rises with the lapse of the film forming time, deteriorating the film quality of the p-type semiconductor layer, The base electrode was damaged and the productivity was remarkably reduced. Therefore, in order to obtain a p-type non-single-crystal semiconductor layer that is spatially and temporally uniform and has good reproducibility, the discharge stability is further improved over a long period of time, and the reproducibility is improved. A method is required. Further, in order to improve the throughput of the device and reduce the cost, a method of forming a semiconductor thin film while maintaining the quality is required. Further, the basic characteristics of the p-type semiconductor layer have a great influence on the characteristics of the photovoltaic element electrically and optically. Particularly, in the laminated photovoltaic element, an extremely good pn junction is required, so that doping There is a demand for a method capable of forming a high-quality p-type semiconductor layer with good efficiency and reproducibly and uniformly.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems in the conventional method for producing a photovoltaic device as described above and to provide a high photoelectric conversion efficiency on a substrate over a large area. Another object of the present invention is to provide a forming method and apparatus for producing a large number of photovoltaic elements having high quality, excellent uniformity, high reproducibility and few defects.

[0008]

Means for Solving the Problems The present invention achieves the above-mentioned object, and introduces a material gas into the discharge space of a reaction vessel, applies electric power to decompose the material gas by plasma discharge, and In a thin film forming method for forming a p-type semiconductor layer at a relatively high deposition rate, the p-type semiconductor layer is formed using a power source corresponding to each of a plurality of independent power application electrodes (cathodes), and glow discharge is performed. At the time of occurrence, at least one of the potential (self-bias) polarities of the plurality of cathodes installed in the discharge space has a self-bias of 0 V, or the self-bias polarities are different so that the p-type A feature is that a semiconductor layer is formed. As means for changing the potential polarities of the plurality of cathodes, a direct current voltage may be superimposed on an alternating current power source, and the surface area of the cathode electrode in the discharge space is made larger or smaller than the surface area of the anode electrode. This makes it possible to control the electrode polarity of the cathode.

[0009]

According to the present invention, the p-type semiconductor layer is formed on the substrate by applying at least one of the potential (self-bias) polarities of the plurality of cathodes installed in the discharge space when the glow discharge occurs. In order to form 0V or different self-bias polarities, the effect of the ions present in the plasma discharge on the deposited film on the substrate, that is, the effect of the energy given to the surface of the deposited film by the ion bombardment is determined by the i-type semiconductor. A p-type semiconductor layer suitable for the interface can be formed by stacking a p-type semiconductor layer on the interface side with the layer, or by stacking a multilayer p-type semiconductor layer as a p-type semiconductor layer on the base electrode or upper electrode side, (EN) Provided is a photovoltaic element having improved output characteristics, particularly open-circuit voltage and fill factor, resulting in improved output characteristics. It is possible. Further, according to the present invention, an extremely good pn junction can be realized particularly in a stacked photovoltaic element, and a photovoltaic element of higher quality can be uniformly formed with good reproducibility. .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of a photovoltaic element according to the present invention and a method for manufacturing the same will be described below in detail with reference to the drawings. FIG. 1 is an example of a cross-sectional view of a photovoltaic element for explaining the concept of the present invention in detail. However, the present invention is not limited to the photovoltaic device having the configuration of FIG. In FIG. 1, 101 is a substrate, 102 is a back electrode, 103 is an n-type semiconductor layer, 104 is an i-type semiconductor layer, and 105 is the first p-type.
Type semiconductor layer, 106 is the second p-type semiconductor layer, 107
Is a transparent electrode, and 108 is a current collecting electrode. Also, in FIG.
The light is incident from the side of the n-type semiconductor layer, but in the case of the photovoltaic element of the structure in which the light is incident from the side of the n-type semiconductor layer, 10
3 is the first p-type semiconductor layer, 104 is the second p-type semiconductor layer, 105 is the i-type semiconductor layer, and 106 is the n-type.
Type semiconductor layer. Further, although FIG. 1 shows a structure in which light is incident from the side opposite to the substrate side, in a photovoltaic element having a structure in which light is incident from the substrate side, the positions of the transparent electrode and the collecting electrode are reversed and 102 is the transparent electrode. , 103 is the first p-type semiconductor layer, 104 is the second p-type semiconductor layer, and 105 is the i
The type semiconductor layer, 106 may be the n-type semiconductor layer, and 107 may be the back electrode.

FIG. 2 is an example of a cross-sectional view of a stacked photovoltaic element for explaining the concept of the present invention in detail. The stacked photovoltaic element of the present invention shown in FIG. 2 has a structure in which three pin junctions are stacked. 219 is a first pin junction counted from the light incident side and 218 is a second pin junction. ,
217 is the third pin junction. These three pins
The junction is formed by stacking on the back surface electrode 202 formed on the substrate 201, and the transparent electrode 215 and the collector electrode 216 are formed on the uppermost part of the three pin junctions to form a stacked photovoltaic. It forms a power element. The respective pin junctions have n-type semiconductor layers 203, 207, and 21.
1, i-type semiconductor layers 204, 208 and 212, first p-type semiconductor layers 205, 209 and 213, and second p-type semiconductor layers 206, 210 and 214. Further, as in the case of the photovoltaic element of FIG. 1, the arrangement of the doping layers and electrodes may be switched depending on the incident direction of light.

The components and manufacturing method of the photovoltaic element of the present invention will be described below.

[Substrate] Semiconductor layers (103 to 106, 203 to 214)
Since it is a thin film of about 1 μm at most, it is deposited on an appropriate substrate. Such substrates (101, 201) may be monocrystalline or non-monocrystalline, and they may be electrically conductive or electrically insulative. Good. Further, they may be light-transmitting or non-light-transmitting, but preferably have a small amount of deformation and distortion and a desired strength. Specifically, Fe, Ni, Cr,
Al, Mo, Au, Nb, Ta, V, Ti, Pt, Pb
Such as metal or alloys thereof, such as brass, thin plates of stainless steel and their composites, and polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, epoxy, etc. Film or sheet of heat resistant synthetic resin or glass fiber, carbon fiber,
Boron fibers, composites with metal fibers, etc., and thin films of these metals, metal thin films of different materials and / or SiO ₂ , Si ₃ N ₄ , Al ₂ O ₃ , on the surface of resin sheets, etc.
An insulating thin film such as AlN that has been surface-coated by a sputtering method, a vapor deposition method, a plating method, or the like, and
Examples thereof include glass and ceramics.

When the substrate is electrically conductive such as metal, it may be used as an electrode for direct current extraction, and when it is electrically insulating such as synthetic resin, Al is formed on the surface on which the deposited film is formed. , Ag, Pt, Au, Ni, Ti, Mo,
So-called simple metals or alloys such as W, Fe, V, Cr, Cu, stainless steel, brass, nichrome, SnO ₂ , In ₂ O ₃ , ZnO and ITO, and transparent conductive oxides (TC)
O) is preferably surface-treated in advance by a method such as plating, vapor deposition, and sputtering to form an electrode for extracting electric current. Of course, even if the substrate is electrically conductive such as metal, it improves the reflectance of long wavelength light on the substrate surface and prevents mutual diffusion of constituent elements between the substrate material and the deposited film. For the purpose of, for example, a different kind of metal layer or the like may be provided on the side where the deposited film is formed on the substrate. Further, when the substrate is relatively transparent and a photovoltaic device having a layer structure in which light is incident from the substrate side is used, a conductive thin film such as the transparent conductive oxide or a metal thin film is previously deposited. It is desirable to form it.

The surface property of the substrate may be a so-called smooth surface or a minute uneven surface. In the case of forming a minute uneven surface, the uneven shape is spherical, conical, pyramidal, or the like, and its maximum height (Rmax) is preferably 0.05 μm to 2 μm, The irregular reflection of light causes an increase in the optical path length of the reflected light on the surface. The shape of the substrate can be a plate shape with a smooth surface or an uneven surface, a long belt shape, a cylindrical shape, etc. depending on the application, and its thickness is appropriately determined so that a photovoltaic element as desired can be formed. However, when flexibility is required for the photovoltaic element, or when light is incident from the substrate side, it should be as thin as possible within the range in which the function as a substrate is sufficiently exhibited. it can. However, it is usually 10 μm or more in terms of mechanical strength in terms of manufacturing and handling of the substrate.

[0015]

[Backside Electrode, Light Reflecting Layer] The backside electrodes (102, 202) used in the present invention are electrodes arranged on the backside of the semiconductor layer in the light incident direction. Therefore, it is arranged at the position of 102 in FIG. 1 or at the position of 107 when the substrate is transparent and light is incident from the direction of the substrate. The material of the back electrode is gold, silver, copper, aluminum, nickel, iron, chromium, molybdenum, tungsten, titanium,
Examples thereof include metals such as cobalt, tantalum, niobium, and zirconium, or alloys such as stainless steel. Among these, metals with high reflectance such as aluminum, copper, silver and gold are particularly preferable. When a metal having a high reflectance is used, the back electrode can also serve as a light reflection layer that reflects light that could not be absorbed by the semiconductor layer back to the semiconductor layer. The shape of the back electrode may be flat, but it is more preferable that the back electrode has an uneven shape for scattering light. By having a concavo-convex shape that scatters light, it scatters long-wavelength light that could not be absorbed by the semiconductor layer and extends the optical path length in the semiconductor layer, improving the long-wavelength sensitivity of the photovoltaic element and increasing the short-circuit current. And the photoelectric conversion efficiency can be improved. In the uneven shape for scattering light, it is desirable that the difference between the heights of the peaks and valleys of the unevenness is 0.2 to 2.0 μm in Rmax. However, when the substrate also serves as the back electrode, the back electrode may not need to be formed in some cases.

Further, a vapor deposition method, a sputtering method, a plating method, a printing method or the like is used for forming the back surface electrode. Further, when the back electrode is formed in a concavo-convex shape that scatters light, the formed metal or alloy film is formed by dry etching, wet etching, sandblasting, heating, or the like. In addition, the above-mentioned metal or alloy can be deposited while heating the substrate to form an uneven shape for scattering light. In addition, the back electrode 102 and the n-type semiconductor layer 10
Although not shown in the figure, a diffusion barrier layer made of conductive zinc oxide or the like may be provided between the first and second electrodes. The effect of the diffusion prevention layer is not only to prevent the metal element forming the back surface electrode 102 from diffusing into the n-type semiconductor layer, but also to provide a slight resistance value so that the back surface provided with the semiconductor layer sandwiched therebetween. To prevent a short circuit caused by a defect such as a pinhole between the electrode 102 and the transparent electrode 107, and to produce multiple interference by a thin film to confine incident light in a photovoltaic element. You can

[0017]

[Semiconductor Layer] As a material of the semiconductor layer used in the present invention, a material using a group IV element such as Si, C, Ge or a group IV alloy such as SiGe, SiC, SiSn is used. Among these semiconductor materials,
The semiconductor material particularly preferably used for the photovoltaic element of the present invention includes a-Si: H (abbreviation of hydrogenated amorphous silicon), a-Si: F, a-Si: H: F, a-. SiG
e: H, a-SiGe: F, a-SiGe: H: F, a
Group IV and group IV alloy-based amorphous semiconductor materials such as -SiC: H, a-SiC: F, and a-SiC: H: F. The semiconductor layer can perform valence electron control and band gap control. Specifically, a raw material compound containing an element serving as a valence electron control agent or a band gap control agent when forming a semiconductor layer is formed alone or mixed with the deposited film forming raw material gas or the dilution gas to form a film. It should be introduced in the space. In addition, at least a part of the semiconductor layer is doped into p-type and n-type by valence electron control to form at least one pair of pin junctions. And pin
By stacking a plurality of junctions, a so-called stacked cell structure is formed.

The semiconductor layer is formed by microwave plasma CVD.
Method, RF plasma CVD method, optical CVD method, thermal CVD method,
By various CVD methods such as MOCVD method, or E
It is formed by various vapor deposition methods such as B vapor deposition, MBE, ion plating, ion beam method, sputtering method, spray method, and printing method. Among these forming methods, a plasma CVD method in which a source gas is decomposed by plasma and deposited on a substrate is preferable. In addition, as a device, a batch type device, a continuous film forming device, or the like can be used as desired.

The semiconductor layer using an amorphous semiconductor material of Group IV element or an alloy type amorphous semiconductor material of Group IV element particularly suitable for the photovoltaic element of the present invention will be described in more detail below. (1) i-type semiconductor layer (intrinsic semiconductor layer) The layer is particularly an amorphous semiconductor material of Group IV element or I
In a photovoltaic device using an alloy-based amorphous semiconductor material of a group V element, the i-type layer used for the pin junction is an important layer that generates and transports carriers with respect to irradiation light. As the i-type layer, only p-type or n-type layers can be used. For the group IV element amorphous semiconductor material or the group IV element alloy-based amorphous semiconductor material, as described above, hydrogen is used. An atom (H, D) or a halogen atom (X) is contained, which has an important function. Hydrogen atoms (H, D) or halogen atoms (X) contained in the i-type layer work to compensate for dangling bonds in the i-type layer, and the mobility of carriers in the i-type layer. And product life. Further, it works to compensate for the interface state of each interface of the p-type layer / i-type layer and the n-type layer / i-type layer, and has the effect of improving the photovoltaic power, photocurrent and photoresponsiveness of the photovoltaic element. There is something. The optimal content of hydrogen atoms and / or halogen atoms contained in the i-type layer is 1 to 40 at%. Particularly, 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 p-type layer / i-type layer and the n-type layer / i-type layer,
The content of hydrogen atoms and / or halogen atoms near the interface is preferably in the range of 1.1 to 2 times the content in the bulk. Further, it is preferable that the content of hydrogen atoms and / or halogen atoms is changed in accordance with the content of silicon atoms.

In the stacked photovoltaic element, the material of the pin junction i-type semiconductor layer near the light incident side has a wide bandgap, and the material of the pin junction i-type semiconductor layer far from the light incident side. For this, it is desirable to use a material having a narrow band gap. Amorphous silicon and amorphous silicon germanium are a-Si: H, a-Si: F, a-S depending on the element that compensates for dangling bonds.
i: H: F, a-SiGe: H, a-SiGe: F, a
-It is written as SiGe: H: F. Furthermore, as a characteristic of the i-type semiconductor layer suitable for the photovoltaic device of the present invention, the hydrogen atom content (C _H ) is 1.0 to 25.0.
%, AM 1.5, photoconductivity (σp) under irradiation of pseudo sunlight of 100 mW / cm ² is 1.0 × 10 ⁻⁷ S / cm or more, and dark conductivity (σd) is 1.0 × 10. ^-9 S / cm or less, Urbach energy by constant photocurrent method (CPM) of 55 meV or less, and localized level density of 10 ¹⁷ / cm ³ or less are preferably used.

(2) p-type semiconductor layer or n-type semiconductor layer The p-type semiconductor layer or the n-type semiconductor layer is a feature of the photovoltaic element of the present invention, and is an important layer that influences its characteristics. Amorphous material of the p-type semiconductor layer or the n-type semiconductor layer (a
−) Or a microcrystalline material (displayed as μc−), for example, a-Si: H, a-Si: HX,
a-SiGe: H, a-SiGe: HX, μc-Si:
H, .mu.c-SiGe: H, .mu.c-SiGe: 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 an n-type valence electron control agent (atoms P, As, Sb, Bi of Group V of the periodic table) at a high concentration are included, and polycrystalline materials (poly- and Is displayed), for example, poly-Si: H, poly-
Si: HX, poly-SiGe: H, poly-Si
Ge: HX, poly-Si, poly-SiGe, and other p-type valence electron control agents (Group III atoms B and A in the periodic table).
1, Ga, In. Examples of the material include Tl) and an n-type valence electron control agent (atoms P, As, Sb, Bi of Group V of the periodic table) at a 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. The optimum amount of the added group III atom of the periodic table to the p-type layer and the added amount of the group V atom of the periodic table to the n-type layer is 0.1 to 50 at%. Further, hydrogen atoms (H, D) or halogen atoms contained in the p-type layer or the n-type layer act to compensate dangling bonds of the p-type layer or the n-type layer and dope the p-type layer or the n-type layer. It improves efficiency. p-type layer or n
The number of hydrogen atoms or halogen atoms added to the mold layer is 0.1.
-40 at% is mentioned as the optimum amount. In particular, when the p-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 preferred distribution form is one in which a large amount of hydrogen atoms and / or halogen atoms is distributed on each interface side of the p-type layer / i-type layer and the n-type layer / i-type layer. The content of the hydrogen atom and / or the halogen atom is preferably in a range of 1.1 to 2 times the content in the bulk. Thus, the p-type layer / i-type layer and the n-type layer / i
By increasing the content of hydrogen atoms or halogen atoms near each interface of the mold layer, the defect level and mechanical strain near the interface can be reduced, and the photovoltaic power and light of the photovoltaic device of the present invention can be reduced. The current can be increased. Regarding the electrical characteristics of the p-type layer and the n-type layer of the photovoltaic element, those having activation energy of 0.2 eV or less are preferable, and 0.1 eV is preferable.
The following are optimal: Also, 100Ω as non-resistance
cm or less is preferable, and 1 Ωcm or less is optimal. Furthermore, the layer thickness of the p-type layer and the n-type layer is preferably 1 to 50 nm, and most preferably 3 to 10 nm.

[0023]

[Transparent Electrode] In the present invention, the transparent electrode 112 is a light-transmission-side electrode that transmits light, and also serves as an antireflection film by optimizing the film thickness. The transparent electrode 112 is required to have high transmittance in the wavelength range in which the semiconductor layer can absorb and low resistivity. Preferably, the transmittance at 550 nm is 80% or more, more preferably 85% or more. The resistivity is preferably 5 × 10 ⁻³ Ω
cm or less, more preferably 1 × 10 ⁻³ Ωcm or less. As its material, In ₂ O ₃ and SnO
₂ , ITO (In ₂ O ₃ + SnO ₂ ), ZnO, CdO, C
d ₂ SnO ₄ , TiO ₂ , Ta ₂ O ₅ , Bi ₂ O ₃ , MoO ₃ ,
A conductive oxide such as Na _x WO ₃ or a mixture thereof is preferably used. In addition, these compounds,
You may add the element (dopant) which changes electric conductivity. As the element (dopant) that changes the conductivity,
For example, when the transparent electrode 103 is ZnO, Al, I
n, B, Ga, Si, F, etc., and in the case of In ₂ O ₃ , Sn, F, Te, Ti, Sb, Pb, etc.
In the case of nO ₂ , F, Sb, P, As, In, Tl,
Te, W, Cl, Br, I and the like are preferably used. As the method of forming the transparent electrode 112, a vapor deposition method, a CVD method,
A spray method, a spin-on method, a dip method and the like are preferably used.

[0024]

[Collector Electrode] In the present invention, the collector electrode 113 is formed on a part of the transparent electrode 112 as necessary when the resistivity of the transparent electrode 112 cannot be sufficiently lowered, and lowers the resistivity of the electrode to reduce the photovoltaic power. It works to reduce the series resistance of the device.
Its materials include gold, silver, copper, aluminum, nickel, iron, chromium, molybdenum, tungsten, titanium,
Examples thereof include metals such as cobalt, tantalum, niobium, and zirconium, alloys such as stainless steel, and conductive paste using powder metal. The shape is formed so as not to block incident light on the semiconductor layer as much as possible. In addition, in the total area of the photovoltaic element,
The area occupied by the collecting electrode is preferably 15% or less, more preferably 10% or less, and most preferably 5% or less.
A mask is used for forming the pattern of the current collecting electrode, and a vapor deposition method, a sputtering method, a plating method, a printing method or the like is used as a forming method.

When a photovoltaic element (module or panel) having a desired output voltage and output current is manufactured using the photovoltaic element of the present invention, the photovoltaic element of the present invention is connected in series or The electrodes are connected in parallel, a protective layer is formed on the front surface and the back surface, and output extraction electrodes and the like are attached.
When the photovoltaic elements of the present invention are connected in series, a diode for preventing backflow may be incorporated.

An example of an apparatus for continuously producing the photovoltaic element of the present invention will be described with reference to FIG. FIG. 3 is a schematic view showing a manufacturing apparatus for continuously manufacturing the photovoltaic element of the present invention, which includes a strip substrate 301, a delivery chamber and a winding chamber 302, 303, an n-type semiconductor layer producing container 304, i. The container for semiconductor layer production 305, the first container for p-type semiconductor layer production 306, and the second container for p-type semiconductor layer production 307 are connected via a gas gate 308. Reference numeral 309 denotes a bobbin for feeding the strip substrate 301, 31
Reference numeral 0 is a bobbin for winding the strip substrate 301, and the strip substrate 301 is conveyed in the direction of the arrow in the drawing. However, the belt-shaped substrate 301 can be reversed and conveyed. Further, in the feeding chamber 302 and the winding chamber 303, winding and feeding means for the interleaving paper 310 used for protecting the surface of the belt-shaped substrate 301 may be arranged. The material of the interleaving paper, a polyimide-based heat-resistant resin,
Teflon type and glass wool are preferably used. Reference numeral 311 is a transport roller that also serves to adjust the tension of the belt-shaped substrate 301 and position it. Reference numeral 312 denotes a film forming gas inlet, which communicates with a gas supply mixing box (not shown). Reference numeral 322 is a gate gas introduction pipe for introducing a gate gas for separating the film forming gas between the film forming chambers. The gas gate 313 is a throttle valve for adjusting conductance, and 314 is an exhaust pipe, which is connected to an exhaust pump (not shown). 315 is an applicator,
A microwave-transmissive member is attached to the tip thereof, and is connected to a microwave power source (not shown) through the waveguide 316. Reference numeral 317 is an electrode, which is connected to the power supply 318.

Each film forming container 304, 305, 306, 30
7, a plurality of infrared lamp heaters 319 are provided in a space opposite to the film formation space with the strip substrate 301 interposed therebetween.
And a lamp house 32 for efficiently concentrating the radiant heat from these infrared lamp heaters on the strip substrate 301.
0 is provided respectively. Further, thermocouples 321 for monitoring the temperature of the strip substrate 301 are connected so as to be in contact with the strip substrate 301, respectively.

In the present invention, a bias voltage may be applied to control the plasma potential of the microwave plasma generated in the film formation space. DC as bias voltage,
It is preferable to apply the pulsating current and the alternating voltage individually or in combination. By controlling the plasma potential of the microwave plasma, the stability, reproducibility, and film characteristics of the plasma can be improved and defects can be reduced. Using an apparatus for continuing the photovoltaic element of the present invention described above,
By manufacturing a photovoltaic element, it is possible to solve the above-mentioned problems and satisfy the above-mentioned requirements, and to manufacture a photovoltaic element having high quality, excellent uniformity, and few defects.

[0029]

EXAMPLES Examples of the method for producing the photovoltaic element of the present invention will be shown below, but the present invention is not limited to these examples.

[0030]

Example 1 A method for continuously producing the photovoltaic element of the present invention using the apparatus shown in FIG. 3 will be described below in accordance with the procedure. (1) A vacuum container 302 having a substrate feeding mechanism is sufficiently degreased and washed, and a silver thin film of 100 nm and a ZnO thin film of 1 μm are vapor-deposited as a lower electrode by a sputtering method.
(0 mm × length 300 m × thickness 0.2 mm) wound bobbin 309 is set, and the strip substrate 301 is
Type semiconductor layer deposition container 304, i-type semiconductor layer deposition container 30
5, the first p-type semiconductor layer film formation container 306 and the second p-type semiconductor layer film formation container 307 are passed through the gas gate 308 to the vacuum container 303 having a belt-shaped substrate winding mechanism, and tension is applied to a degree without slack. Adjustments were made. (2) Each vacuum container 302, 303, 304, 305, 3
06, 307 to 1 × 10 ^-6 To with a vacuum pump (not shown)
A vacuum was drawn to below rr. (3) Heat treatment before film formation: H ₂ as a gate gas is introduced into the gas gate 308 from the gate gas introduction pipe 322 to 500 times each.
cc / min flow into each film forming container from the gas introduction pipe 322 to H
500 cc / min for each e, and each vacuum container 30
2,303,304,305,306,307,308
Throttle valve 3 to adjust the internal pressure to 1.0 Torr
The opening degree of 14 was adjusted, and each vacuum container was evacuated by a vacuum pump (not shown) through the exhaust pipe 313 of each vacuum container. Then, the belt-shaped substrate and the members inside the vacuum container were heated to 400 ° C. by the heating lamp heater 321, and left in this state for 1 hour. (4) Each vacuum container 302, 303, 304, 305, 3
06, 307 to 1 × 10 ^-6 To with a vacuum pump (not shown)
A vacuum was drawn to below rr. (5) Gate gas introduction at the time of film formation: H ₂ is used as a geto gas in each gas gate 308 from the gate gas introduction pipe 322.
Introduced at 00 cc / min.

(6) Preparation of n-type semiconductor layer film formation: thermocouple 32
A temperature control device (not shown) was set so that the temperature instruction value of 1 became 270 ° C., and the band-shaped substrate 301 was heated by the infrared lamp heater 319. From the gas inlet 312,
SiH ₄ gas at 100 cc / min, PH ₃ / H ₂ (1
%) Gas 500 cc / min, H ₂ gas 700 cc
/ Min introduced. The opening of the conductance adjusting valve 313 was adjusted so that the pressure in the discharge chamber was 1.0 Torr, and the gas was exhausted through a gas exhaust pipe 314 by a vacuum pump (not shown). The output value of the RF (13.56 MHz) power supply 318 was set to 100 W, and a discharge was generated in the discharge chamber through the electrode 317. (7) Preparation of i-type semiconductor layer film formation: A temperature control device (not shown) is set so that the temperature indication value of the thermocouple 321 becomes 360 ° C., and the band-shaped substrate 30 is set by the infrared lamp heater 319.
1 was heated. From the gas introduction pipe 312, SiH ₄ gas is 50 cc / min, GeH ₄ gas is 50 cc / min,
H ₂ gas was introduced at 200 cc / min. The opening of the conductance adjusting valve 313 was adjusted so that the pressure in the discharge chamber was 20 mTorr, and the pressure was exhausted by a vacuum pump (not shown). Microwave (2.45 GHz) electric power was introduced into the applicator 315, and 200 W of microwave electric power was introduced through the microwave transparent member to generate discharge in the discharge chamber. (8) First p-type semiconductor layer film formation preparation: A temperature control device (not shown) was set so that the temperature instruction value of the thermocouple 321 was 270 ° C., and the band-shaped substrate 301 was heated by the infrared lamp heater 319. . From the gas inlet 312, SiH
₄ gas at 10 cc / min, BH ₃ / H ₂ (1%) gas at 200 cc / min, H ₂ gas at 1000 cc / min
Introduced. The opening of the conductance adjusting valve 313 was adjusted so that the pressure in the discharge chamber was 1.0 Torr, and the gas was exhausted through a gas exhaust pipe 314 by a vacuum pump (not shown). The output value of the RF power supply 318 was set to 500 W, and 50 V was superimposed by a DC power supply (not shown) to make the polarity of the self-bias value positive, and a discharge was generated in the discharge chamber through the electrode 317.

(9) Second p-type semiconductor layer film formation preparation: The first p-type semiconductor layer of (7) except that the DC voltage is not superimposed in the above-mentioned first p-type semiconductor layer film formation preparation. It was the same as in the case of the film formation preparation. (10) Mount the strip substrate 501 in the direction of the arrow in the drawing
The n-type semiconductor layer, the n / i diffusion preventive layer, the i-type semiconductor layer, the p-type semiconductor layer, and the belt-shaped substrate were conveyed at a speed of mm / min.
A p / i diffusion prevention layer and a p-type semiconductor layer were produced. (11) After transporting one roll of the strip-shaped substrate, all plasma, supply of all gases, energization of all lamp heaters, and transport of the strip-shaped substrate were stopped. Next, N ₂ gas for chamber leak was introduced into the chamber (introducing member is not shown) and returned to atmospheric pressure, and the strip substrate wound on the winding bobbin was taken out. (12) As a transparent electrode on the p-type semiconductor layer, ITO (I
n ₂ O ₃ + SnO ₂ ) is vapor-deposited to a thickness of 100 nm,
Further, as a collecting electrode, Al was vacuum-deposited to a thickness of 1 μm to fabricate the photovoltaic element (Sample No. 1) shown in FIG. Table 1 shows the conditions for manufacturing the above photovoltaic element.

[0033]

Comparative Example 1 In this example, a photovoltaic element was manufactured in the same manner as in Example 1 except that the heating temperature of the belt-shaped substrate in the diffusion prevention layer was kept constant. The differences from the first embodiment will be summarized below. (1) The first p-type semiconductor layer is made to have the same conditions as the second p-type semiconductor layer. In other respects, the photovoltaic element (comparative sample N
o. 1) was produced.

[0034]

[Evaluation] The photovoltaic element obtained in Example 1 (Sample No.
1) and the photovoltaic element obtained in Comparative Example 1 (Comparative Sample No. 2), photoelectric conversion efficiency η = {maximum generated power per unit area (mW / cm ² ) incident light per unit area The strength (mW / cm ² )} was evaluated. Sample No. of Example 1 No. 1 and Comparative Sample No. 1 of Comparative Example 1. Five photovoltaic elements of No. 1 each were prepared, and A
It was placed under M-1.5 (100 mW / cm ² ) light irradiation, a DC voltage was applied to the upper electrode 110 of FIG. 1, current-voltage characteristics were measured, and open circuit voltage, fill factor and photoelectric conversion efficiency η were evaluated. However, the comparative sample No. Sample No. 1 for the photovoltaic element No. 1 In the photovoltaic element No. 1, the open-circuit voltage value is 1.14 times on average, the fill factor value is 1.1 times on average, and the photoelectric conversion efficiency η is 1.25 times on average.
Was twice as good. Further, the photovoltaic element manufactured in Example 1 and the photovoltaic element manufactured in Comparative Example 1 (Comparative Sample N
o. Each of 1) is vacuum-sealed with a protective film made of polyvinylidene fluoride (VDF), left under actual use conditions (installed outdoors, fixed resistance of 50Ω is connected to both electrodes) for 1 year, and then photoelectric conversion is performed again. The efficiency was evaluated, and the deterioration rate due to light irradiation (the value of the photoelectric conversion efficiency damaged by the deterioration divided by the initial photoelectric conversion efficiency) was examined. as a result,
The deterioration rate of the photovoltaic element (Sample No. 1) formed with the diffusion prevention layer according to the present invention is relative to the deterioration rate of the photovoltaic element (Comparative sample No. 1) formed with the p-type semiconductor layer by the conventional method. The ratio was as low as 40%. From the above, it has been found that the photovoltaic device manufactured according to the present invention has a dramatic improvement in photoelectric conversion efficiency and a drastic improvement in reliability under actual use conditions.

[0035]

Example 2 An n-type semiconductor layer, an i-type semiconductor layer, a first p-type semiconductor layer, a second p-type semiconductor layer and a second p-type semiconductor layer were prepared in the same manner as in Example 1 except that the production conditions of the p-type semiconductor layer were changed to those shown in Table 2. A p-type semiconductor layer, a transparent electrode, and a collector electrode are sequentially formed, and a photovoltaic element (Sample N
o. 2) was produced.

[0036]

Comparative Example 2 In this example, a photovoltaic element was manufactured in the same manner as in Example 2 except for the conditions for manufacturing the p-type semiconductor layer. The differences from the first embodiment will be summarized below. (1) The first p-type semiconductor layer is made to have the same conditions as the second p-type semiconductor layer. Otherwise, the photovoltaic element (comparative sample N
o. 2) was produced.

[0037]

[Evaluation] The photovoltaic element obtained in Example 2 (Sample No.
2) and the photovoltaic element (Comparative Sample No. 2) obtained in Comparative Example 2 were evaluated for photoelectric conversion efficiency η. In the sample No. of Example 2, No. 2 and Comparative Sample No. 2 of Comparative Example 2. Five photovoltaic elements of No. ² were prepared, placed under AM-1.5 (100 mW / cm ² ) light irradiation, a DC voltage was applied to the upper electrode 110 of FIG. 1, and the current-voltage characteristics were measured. The open circuit voltage, the fill factor, and the photoelectric conversion efficiency η were evaluated. For the photovoltaic element of Sample No. 2, In the photovoltaic element No. 1, the open circuit voltage value is 1.17 times on average, the fill factor value is 1.1 times on average, and the photoelectric conversion efficiency η is 1.
It was three times better. In addition, the photovoltaic element manufactured in Example 2 and the photovoltaic element manufactured in Comparative Example 2 (Comparative Sample N
o. Each of 1) is vacuum-sealed with a protective film made of polyvinylidene fluoride (VDF), left under actual use conditions (installed outdoors, fixed resistance of 50Ω is connected to both electrodes) for 1 year, and then photoelectric conversion is performed again. The efficiency was evaluated, and the deterioration rate due to light irradiation (the value of the photoelectric conversion efficiency damaged by the deterioration divided by the initial photoelectric conversion efficiency) was examined. as a result,
The deterioration rate of the photovoltaic element (Sample No. 2) formed with the diffusion prevention layer according to the present invention is relative to the deterioration rate of the photovoltaic element (Comparative sample No. 2) formed with the p-type semiconductor layer by the conventional method. The ratio was as low as 50%. From the above, it has been found that the photovoltaic device manufactured according to the present invention has a dramatic improvement in photoelectric conversion efficiency and a drastic improvement in reliability under actual use conditions.

[0038]

[Embodiment 3] In this embodiment, in manufacturing the first p-type semiconductor layer in Example 1, a positive voltage was superposed by a DC power supply in order to make the polarity of the self-bias value positive. An experiment was conducted by increasing the surface area of the cathode electrode in the space with respect to the surface area of the anode electrode to make the polarity of the self-bias value positive. The self-bias value at that time is +230 V, and the other conditions are the same as in the case of Example 1, and the n-type semiconductor layer, the i-type semiconductor layer, the first p-type semiconductor layer, and the second p-type semiconductor are used. A layer, a transparent electrode, and a collector electrode are sequentially formed, and a photovoltaic element (Sample No.
3) was produced.

[0039]

[Evaluation] Photovoltaic device obtained in Example 3 (Sample No.
3) and the photovoltaic element (Comparative Sample No. 2) obtained in Comparative Example 2 were evaluated for photoelectric conversion efficiency η. Sample No. of Example 3 3 and Comparative Sample No. 2 of Comparative Example 2. Five photovoltaic elements of No. ² were prepared, placed under AM-1.5 (100 mW / cm ² ) light irradiation, a DC voltage was applied to the upper electrode 110 of FIG. 1, and the current-voltage characteristics were measured. The open circuit voltage, the fill factor, and the photoelectric conversion efficiency η were evaluated. For the photovoltaic element of Sample No. 2, The photovoltaic element of 1 is
The open circuit voltage value was 1.19 times higher on average, the fill factor value was 1.2 times higher on average, and the photoelectric conversion efficiency η was 1.4 times higher on average. In addition, each of the photovoltaic element manufactured in Example 2 and the photovoltaic element manufactured in Comparative Example 2 (Comparative Sample No. 1) was made into polyvinylidene fluoride (VDF).
After vacuum-sealing with a protective film consisting of, and putting it under actual use conditions (outdoor installation, connecting a fixed resistance of 50Ω to both electrodes) for 1 year, the photoelectric conversion efficiency is evaluated again, and it is caused by light irradiation. The deterioration rate (the value of the photoelectric conversion efficiency damaged by the deterioration divided by the initial photoelectric conversion efficiency) was examined. As a result, the deterioration rate of the photovoltaic device having the p-type semiconductor layer formed according to the present invention (Sample No. 3) was reduced by the conventional method. Was suppressed to as low as 50% of the deterioration rate. From the above, it has been found that the photovoltaic device manufactured according to the present invention has a dramatic improvement in photoelectric conversion efficiency and a drastic improvement in reliability under actual use conditions.

[0040]

[Embodiment 4] In this embodiment, three sets of pin junctions are laminated and used instead of providing one set of pin junctions on the surface of the lower electrode in the first embodiment. When three sets of pin junctions are stacked in this way, it is called a triple type photovoltaic element. Here, in the pin junction on the light incident side, RF discharge was used as the discharge generating means for forming the i-type semiconductor layer, and it was the same as in Example 1. When the above-mentioned triple photovoltaic element is manufactured, a new n-type semiconductor layer is newly provided between the second p-type semiconductor layer deposition container 307 and the winding chamber 303 of the deposited film forming apparatus shown in FIG. Film forming container, i-type semiconductor layer film forming container, first p-type semiconductor layer film forming container, second p-type semiconductor layer film forming container, n-type semiconductor layer film forming container, i-type semiconductor layer film forming container, An apparatus was used in which the first p-type semiconductor layer film formation container and the second p-type semiconductor layer film formation container were connected via gas gates 308 and added. First and second pin
The junction is a-SiGe: H, and the third pin junction is a-Si: H to form the i-type semiconductor layers.
The production conditions are shown in Tables 3 and 4. The stacking order is the order shown in Tables 3 and 4. Subsequently, the produced photovoltaic element was processed into a large number of photovoltaic element modules having a size of 36 cm × 22 cm using a continuous modularization apparatus (not shown). The characteristics of the processed photovoltaic element module were evaluated by using artificial sunlight with an energy density of 100 mW / cm ² at AM 1.5 and found to be 7.8%.
The above photoelectric conversion efficiency was obtained, and the variation in characteristics among the photovoltaic element modules was within 5%. In addition, when two pieces were taken out from the processed photovoltaic element module and a repeated bending test was performed 200 times continuously, the characteristics did not deteriorate even after the test, and phenomena such as peeling of the deposited film were also recognized. I couldn't do it. Furthermore, the photoelectric conversion efficiency was within 8.5% of the initial value even after continuous irradiation with the above-mentioned AM1.5 of pseudo-sunlight having an energy density of 100 mW / cm ² for 500 hours. By connecting this photovoltaic element module, a power supply system with an output of 5 kW could be constructed.

[0041]

Fifth Embodiment In the fourth embodiment described above, an a-Si: H deposited film is used as the second p-type semiconductor layer.
A photovoltaic element was manufactured using an a-SiC: H deposited film instead of the —Si: H deposited film, and processed into a photovoltaic element module. Regarding the processed photovoltaic element module,
When the same characteristics as in Example 3 were evaluated, it was 7.8%.
The above photoelectric conversion efficiency was obtained, and the variation in the characteristics among the photovoltaic element modules was within 5%. Further, even after the continuous bending test of 200 times, no deterioration of the characteristics was observed, and no peeling of the deposited film occurred.
Furthermore, even after the continuous 500 hours of pseudo-sunlight irradiation, the variation in photoelectric conversion efficiency was within 8.3% of the initial value. By using this photovoltaic element module, a power supply system with an output of 5 kW could be constructed.

[0042]

Sixth Embodiment In the fourth embodiment described above, the polarities of the self-bias at the time of manufacturing the p-type semiconductor layer are made to be in the order of negative and positive with respect to the i-type semiconductor layer. Then, the film formation order of the first p-type semiconductor layer and the second p-type semiconductor layer was reversed so as to be positive and negative.
Specific values are shown in Tables 5 and 6. The processed photovoltaic element module was evaluated for characteristics in the same manner as in Example 3. As a result, a photoelectric conversion efficiency of 7.0% or more was obtained, and variation in characteristics among the photovoltaic element modules was within 5%. Was set in. Further, even after the continuous bending test of 200 times, no deterioration of the characteristics was observed, and no peeling of the deposited film occurred. Furthermore, the fluctuation of the photoelectric conversion efficiency was within 10% of the initial value even after the continuous irradiation of pseudo sunlight for 500 hours. By using this photovoltaic element module, a power supply system with an output of 5 kW could be constructed.

[0043]

[Embodiment 7] In Embodiment 4 described above, the self-bias of the first p-type semiconductor layer was formed to have a positive polarity. Here, the self-bias of the first p-type semiconductor layer is 0 V.
It was prepared so that Specific values are shown in Tables 7 and 8. When the processed photovoltaic element module was evaluated for characteristics in the same manner as in Example 3, it was 7.0.
A photoelectric conversion efficiency of not less than 5% was obtained, and variations in characteristics among the photovoltaic element modules were within 5%. Further, even after the continuous bending test of 200 times, no deterioration of the characteristics was observed, and no peeling of the deposited film occurred.
Furthermore, the fluctuation of the photoelectric conversion efficiency was within 10% of the initial value even after the continuous irradiation of pseudo sunlight for 500 hours. By using this photovoltaic element module, a power supply system with an output of 5 kW could be constructed.

[0044]

[Embodiment 8] In Embodiment 4 described above, the self-bias of the second p-type semiconductor layer was formed to have a negative polarity, but here, the self-bias of the second p-type semiconductor layer is 0 V.
It was prepared so that Specific values are shown in Table 9 and Table 10. When the processed photovoltaic element module was evaluated for characteristics in the same manner as in Example 3, 7.
A photoelectric conversion efficiency of 0% or more was obtained, and the variation in characteristics among the photovoltaic element modules was within 5%.
Further, even after the continuous bending test of 200 times, no deterioration of the characteristics was observed, and no peeling of the deposited film occurred. Furthermore, the fluctuation of the photoelectric conversion efficiency was within 10% of the initial value even after the continuous irradiation of pseudo sunlight for 500 hours. By using this photovoltaic element module, a power supply system with an output of 5 kW could be constructed.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

[Table 5]

[0050]

[Table 6]

[0051]

[Table 7]

[0052]

[Table 8]

[0053]

[Table 9]

[0054]

[Table 10]

[0055]

As described above, the p-type semiconductor layer is formed on the substrate by at least one of the potential (self-bias) polarities of the plurality of cathodes installed in the discharge space when glow discharge occurs. Since the self-bias is formed with 0 V or the self-bias polarity is different, the effect of the ions present in the plasma discharge on the deposited film on the substrate, that is, the effect of energy given to the deposited film surface by the ion bombardment, By stacking a p-type semiconductor layer on the interface side with the i-type semiconductor layer or a multi-layered p-type semiconductor layer as a p-type semiconductor layer on the base electrode or upper electrode side, a p-type semiconductor layer suitable for the interface can be obtained. A photovoltaic element that can be formed and has improved output characteristics, especially open-circuit voltage and fill factor, resulting in improved output characteristics. It is possible to provide a. In addition, especially in stacked photovoltaic devices, p
An n-junction can be realized, and a higher quality photovoltaic element can be formed uniformly with good reproducibility.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a layer configuration of a non-single crystalline silicon photovoltaic element according to the present invention.

FIG. 2 is a schematic configuration diagram for explaining a layer configuration of a stacked photovoltaic element of a non-single crystalline silicon photovoltaic element according to the present invention.

FIG. 3 is a schematic view of an example of the photovoltaic device manufacturing apparatus according to the first embodiment.

[Explanation of symbols]

 101 substrate 102 back surface electrode 103 n-type semiconductor layer 104 i-type semiconductor layer 105 first p-type semiconductor layer 106 second p-type semiconductor layer 107 transparent electrode 108 current collecting electrode 201 substrate 202 back surface electrode 203 n-type semiconductor layer 204 i Type semiconductor layer 205 first p-type semiconductor layer 206 second p-type semiconductor layer 207 n-type semiconductor layer 208 i-type semiconductor layer 209 first p-type semiconductor layer 210 second p-type semiconductor layer 211 n-type semiconductor layer 212 i-type semiconductor layer 213 first p-type semiconductor layer 214 second p-type semiconductor layer 215 transparent electrode 216 current collecting electrode 301 band-shaped substrate 302 delivery vacuum container 303 winding vacuum container 304 n-type semiconductor layer deposition container 305 i -Type semiconductor layer deposition container 306 First p-type semiconductor layer deposition container 307 Second p-type semiconductor layer deposition container 309 Feed And the bobbin 310 take-up bobbin 311 transport rollers 312 deposition gas inlet 313 conductance regulating valve 314 exhaust pipe 315 applicator 316 waveguide 317 electrode 318 power 320 lamp heater 321 Ranbuhausu 322 thermocouple 323 gate gas inlet pipe

Claims (2)

[Claims] 1. A thin film forming method for forming a p-type semiconductor layer by introducing a material gas into a discharge space of a reaction vessel and applying an electric power to decompose the material gas by plasma discharge. A semiconductor layer is formed by using a power source corresponding to each of a plurality of independent power application electrodes (cathodes), and the potentials (self-bias) of the plurality of cathodes installed in the discharge space when a glow discharge occurs. A method for forming a non-single-crystal semiconductor thin film, wherein the p-type semiconductor layer is formed such that at least one of the polarities has a self-bias of 0 V or the self-bias polarity is different. 2. The photovoltaic device according to claim 1, wherein the strip-shaped substrate is moved in the longitudinal direction thereof and continuously passed through a space for forming the plurality of p-type semiconductor layers. Method.