JP2829656B2 - Photovoltaic element - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a photovoltaic element improved as a solar cell suitable for a power supply system for consumer appliances and a power supply system using solar power. More specifically, the present invention relates to a photovoltaic device using a pin heterojunction and having high photoelectric conversion efficiency particularly for short wavelength light.

[Description of Prior Art]

Conventionally, as a photovoltaic element for a power supply for consumer equipment or a solar cell for photovoltaic power generation, it is formed by ion-implanting or thermally diffusing impurities into a single crystal substrate such as silicon (Si) or gallium arsenide (GaAs). Alternatively, a photovoltaic element using a pn junction formed by epitaxially growing a layer doped with an impurity on such a single crystal substrate has been proposed. However, since these photovoltaic elements use a single crystal substrate as described above as a substrate, the manufacturing cost is extremely high, and the reduction is technically difficult. The fact is that it has not been reached.

By the way, in recent years, glass, metal,
Amorphous silicon (hereinafter, referred to as glow discharge decomposition method) is mounted on a substrate of inexpensive material such as ceramics and synthetic resin.
It is called "A-Si". ) A photovoltaic element using a pin junction formed by stacking semiconductor deposition films has been proposed.
Although the photoelectric conversion efficiency of the above-mentioned single-crystal pn junction solar cell has not been obtained, it is widely used as a power source for low-cost consumer appliances such as calculators and watches because of its relatively easy manufacturing method and low cost. Is coming.

In this pin-junction type photovoltaic element, the Fermi level of an A-Si semiconductor having excellent photoelectric characteristics is located slightly closer to the conduction band from the center of the band gap, so that the p-type semiconductor is more p-type than the ni-junction interface. electric field strength is strong at the i-junction interface,
It is said that making light incident from the p-type semiconductor layer side is advantageous for improving the photoelectric conversion efficiency.

On the other hand, when there are many defects serving as recombination centers in the p-type semiconductor layer, light absorbed in the p-type semiconductor layer hardly contributes to generation of a photocurrent. It is desirable that the semiconductor film be formed of a semiconductor film with a minimum of light absorption and few defects. However, as a semiconductor material used for the p-type semiconductor layer in the pin junction type A-Si photovoltaic device, amorphous silicon carbide having a wide band gap (hereinafter, referred to as "A-SiC").
Alternatively, microcrystalline silicon (hereinafter referred to as “μC-Si”), which has a small band gap but a small absorption coefficient due to being an indirect transition type semiconductor material, and has a small light absorption at a thickness of 100 to 200 mm. ) Is being considered. However, in A-SiC, it is possible to widen the band gap by increasing the composition ratio of carbon atoms in the film. However, when the band gap becomes 2.1 eV or more, the film quality rapidly decreases, so that the solar cell There is naturally a limit to the improvement of the characteristics.

Also in the case of μC-Si, since the band gap is essentially narrow, the amount of light absorption cannot be ignored. In particular, in the case of incident light in which the proportion of short-wavelength light components is large, the amount of absorbed light increases significantly.

Therefore, in order to form a photovoltaic element having higher photoelectric conversion efficiency, if the p-type semiconductor layer side is the light incident side, a p-type semiconductor having a wider band gap, a lower defect density, and an unprecedented characteristic. Type semiconductor materials need to be provided urgently.

In addition, as long as the n-type semiconductor material has a sufficiently wide band gap and a low defect density, a photovoltaic element can be configured with the side on which the n-type semiconductor layer is provided as a light incident side. Further, in a so-called tandem type photovoltaic element formed by laminating pin junction type photovoltaic elements and a triple type photovoltaic element, light having a wavelength component that cannot be absorbed by the upper photovoltaic element is used. In order to allow the p-type semiconductor layer and the n-type semiconductor layer to have a sufficiently wide band gap and a low defect density in order to transmit the No.

Further, the p-type or n-type semiconductor material can be directly deposited on non-single-crystal substrates such as glass, metal, ceramics, and synthetic resin, as well as i-type semiconductor deposited on these non-single-crystal substrates. It must be possible to deposit without adversely affecting the layer.

BP has been proposed and evaluated as a semiconductor material having a wide band gap that satisfies such requirements. Specifically, JP-A-56-11667 (hereinafter referred to as "Document 1"), JP-A-61-189629 (hereinafter referred to as "Document 2"), and
No. 61-189630 (hereinafter referred to as "Document 3").

However, document 1 shows that in a pin heterojunction type amorphous thin film solar cell, an amorphous boron phosphate (a-BP) film is formed by a glow discharge decomposition method as a p-type or n-type amorphous semiconductor layer. Although the i-type semiconductor is formed of fluorine-based amorphous silicon, the BP film is limited to an amorphous structure, and detailed characteristics of the formed solar cell are not disclosed. There is no mention of a crystalline BP film. Further, there is no mention of amorphous silicon germanium (A-SiGe) as an i-type semiconductor.

Furthermore, there is no mention of tandem or triple photovoltaic devices.

Documents 2 and 3 refer to HRCVD (Hydrogen Radical assi
When depositing a group III-V compound semiconductor film by a (sted CVD) method, the content of the film is to increase the film deposition rate to dramatically improve the productivity of the film, and specifically discloses a BP film. Has not been done.

Against this background, a desired photoelectric conversion efficiency, particularly a high efficiency photoelectric conversion efficiency for short-wavelength light, is obtained. As a solar cell for a power supply system using solar power as well as a power supply for consumer appliances. There is a social demand for early provision of a photovoltaic element that is practical and inexpensive and has high reliability.

[Object of the invention]

An object of the present invention is to solve the conventional problems relating to a photovoltaic element constituting a solar cell or the like and to provide a photovoltaic element satisfying the above-mentioned social demands and the like.

Another object of the present invention is to form a good pin junction even when deposited and formed on a substrate of inexpensive material such as glass, metal, ceramics, and synthetic resin that is a non-single-crystal substrate,
It is an object of the present invention to provide a photovoltaic element capable of effectively converting incident light, particularly its short wavelength light component, into a photocurrent.

[Summary of the invention, effects]

Means for Solving the Problems The present inventors have overcome the conventional problems of a wide band gap semiconductor deposited film suitable for use as a window layer of a photovoltaic element such as a solar cell, and have intensively studied to achieve the object of the present invention. , BP film, the average crystal grain size is in a specific range, a polycrystalline semiconductor deposited film containing a specific amount of hydrogen atoms and optionally fluorine atoms (hereinafter, referred to as
It is referred to as "BP: H (F) film". ), The semiconductor deposited film can be deposited in a desired state on the surface of a substrate made of glass, metal, ceramics, synthetic resin, etc., and has very few defects in the film. The following is a finding that a crystalline film having a high doping efficiency and a good p-type or n-type conductivity can be introduced into a desired state by introducing an amount of a p-type or n-type doping agent into a desired state. Obtained from experimental results.

According to the present invention, the present inventors have further studied based on the above findings, and have found that a crystalline film having the above-mentioned excellent characteristics can be formed into a p-type and / or n-type semiconductor of a photovoltaic device using a pin junction. It has been applied to layers and completed.

 The present invention includes the following two photovoltaic elements.

(1) A photovoltaic device having a junction structure of a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer, wherein at least one of the p-type semiconductor layer and the n-type semiconductor layer among the semiconductor layers One of which is a hydrogen atom and / or a fluorine atom,
the average crystal grain size including a p-type or n-type valence electron controlling atom is
A polycrystalline BP thin film having a thickness of 50 to 800 °, wherein the content of the hydrogen atoms is 0.5 to 7 atomic%, and the i-type semiconductor layer is formed of a non-single-crystal silicon semiconductor containing a hydrogen atom and / or a fluorine atom. (2) a photovoltaic element having a junction structure of a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer, wherein at least one of the semiconductor layers Either the p-type semiconductor layer or the n-type semiconductor layer is a hydrogen atom and / or a fluorine atom,
the average crystal grain size including a p-type or n-type valence electron controlling atom is
A polycrystalline BP thin film having a thickness of 50 to 800 °, wherein the content of the hydrogen atoms is 0.5 to 7 atomic%, and the i-type semiconductor layer contains germanium atoms and / or carbon atoms, hydrogen atoms and / or fluorine atoms, A photovoltaic device comprising a non-single-crystal silicon alloy-based semiconductor containing:

The results of experiments performed by the present inventors will be described in detail below.

[Experiment]

Experiment A. BP: H with a hydrogen atom and optionally a fluorine atom introduced
(F) Study on film formation method (1) HRCVD method In this method, a source gas containing B atoms, a source gas containing P atoms, and a source gas containing hydrogen gas (H ₂ ) and fluorine atoms Is activated alone or in a mixed state in an activation space different from the film formation space, and B
A precursor containing atoms, a precursor containing P atoms, and hydrogen radicals and fluorine radicals are introduced into the film formation space and chemically reacted, and BP is placed on the substrate heated and held in the film formation space. : H (F) to form a polycrystalline semiconductor deposited film.

This will be described specifically with reference to a schematic diagram of the deposited film forming apparatus shown in FIG.

201 is a film forming chamber having means for performing the method of the present invention, the substrate 203 is held on a substrate holding cassette 202,
It can move on the substrate transfer jig 206. A thermocouple 204 is used for monitoring when the temperature of the substrate 203 is heated and held by the heater 205. Reference numeral 212 denotes a load lock chamber, which has a built-in substrate transfer jig 206 and can vacuum transfer the substrate through a gate valve 207. Reference numeral 222 denotes a film formation chamber which is effectively used when a semiconductor layer formed of a material different from that formed in the film formation chamber 201 is stacked, and is similar to that provided in the film formation chamber 201. Or other different film forming means (not shown). 208,209,210
Is an activation chamber for the source gas for film formation, and the gas supply pipe 21
The source gas introduced from 4,215,216 is activated by electricity, heat, light energy, etc. supplied from the excitation energy generators 211,212,213, and the precursor, hydrogen radicals, etc. generated here pass through the transport pipes 217,218,219 to form a film forming chamber. When introduced into the substrate 201, a chemical interaction occurs, and a semiconductor film having desired characteristics is formed on the substrate 203. Reference numeral 221 denotes an exhaust pump, which controls the pressure in the film forming chamber 201 monitored by the pressure gauge 223 by adjusting the opening of the throttle valve 220.

First, a Corning # 7059 glass substrate 203 having a size of 2 inches × 2 inches and a thickness of 0.8 mm was set in a substrate holding cassette 202, and BP: H (F) film sample No. 1 was formed under the film forming conditions shown in Table 1. ~
10 were produced.

A part of the obtained sample was cut out and SIMS (CAMEA ims
-3f) was used to determine the content of hydrogen and fluorine atoms in the deposited film using XMA (X-ray microanalyzer EPM manufactured by Shimadzu Corporation).
-810Q) to analyze the distribution state and elemental composition of B and P atoms in the deposited film, and use an X-ray diffractometer (RADI
IB), the crystal orientation and the average crystal grain size were measured. Table 2 summarizes the measurement results.

From these results, it is found that in the present method, the hydrogen atom content and the fluorine atom content in the volume film, and further the average crystal grain size can be controlled by changing the amount of H ₂ gas introduced into the activation chamber 209. Was. H ₂ gas introduction amount 0scc
In Samples Nos. 1 and 2 prepared at m and 0.2 sccm, no hydrogen radicals were supplied to the reaction system or the amount was small, so that the amount of contained hydrogen atoms was small, the amount of fluorine atoms was large, and the number of B atoms was large. The distribution of P and P atoms was localized and the structure had no orientation (random). However, in Samples Nos. 3 to 7, the composition of B and P atoms increased with an increase in the amount of H ₂ gas introduced. The ratio became to satisfy the stoichiometric ratio, a specific crystal orientation occurred, and the average crystal grain size tended to increase. Further, the sample was prepared by further increasing the H ₂ gas introduction rate
In Nos. 8 to 10, the supply amount of hydrogen radicals to the reaction system was excessive, so that the average crystal grain size and the hydrogen atom content tended to decrease due to etching of the deposited film and the like.
Thus, it became clear that the supply amount of the hydrogen radical to the reaction system plays an important role in forming the deposited film.

According to the experiment performed in parallel with this experiment, the substrate temperature, pressure, microwave input power, dilution gas (He) flow ratio, distance between the gas outlet of the transport pipe and the substrate, and the combination of source gas some of the hydrogen atom content and fluorine content by parameter changes such as changes of news but which was capable of controlling the average crystal grain size, inferior compared to the control due to the change of the H ₂ gas introduction rate described above I was

(2) Reactive sputtering method In this method, a substrate is placed in a film formation chamber, a cathode electrode is placed at a position facing the substrate and leaving a predetermined space between the substrate and the substrate, and a surface of the cathode electrode is placed on the surface of the cathode electrode. Ar gas and a deposition chamber in which a non-doped polycrystalline or single crystal BP wafer as a target or a polycrystalline or single crystal BP wafer in which H atoms and / or F atoms are dosed by ion implantation are arranged.
H ₂ gas and / or F ₂ , HF gas are introduced, a high-frequency voltage is applied to the cathode electrode to form the gas plasma atmosphere in the space, and the target, such as the polycrystalline BP wafer, is sputtered. B jumping out of
A polycrystalline semiconductor deposited film composed of BP: H (F) by chemically reacting atoms and P atoms with atomic hydrogen and / or fluorine present in the gas plasma in a space near the surface of the substrate. Is formed on the substrate held by heating.

This will be described specifically with reference to a schematic diagram of the deposited film forming apparatus shown in FIG.

Reference numeral 301 denotes a film forming chamber having means for performing the method of the present invention, and a substrate 303 is held on a substrate holding cassette 302;
It can move on the substrate transfer jig 306. A thermocouple 304 is used for monitoring when the temperature of the substrate 303 is heated and held by the heater 305. Reference numeral 313 denotes a load lock chamber, which has a built-in substrate transfer jig 306 and can vacuum transfer the substrate through a gate valve 307.

Reference numeral 316 denotes a film formation chamber which is effectively used when a semiconductor layer formed of a material different from that formed in the film formation chamber 301 is stacked, and is similar to that provided in the film formation chamber 301. Or other different film forming means (not shown).

Reference numeral 312 denotes a cathode electrode on which, for example, a polycrystalline BP wafer is bonded as a target 317. Further, high-frequency power is supplied to the cathode electrode 312 from a high-frequency power supply 310 via a matching box 311, and the gas introduction pipe 3
The sputtering gas such as Ar, H ₂ , F ₂ , HF introduced from 08 is turned into plasma. By the ion species generated in the plasma, B atoms and P atoms are sputtered from the target 317, causing a chemical interaction with atomic hydrogen and / or fluorine present in the plasma, and causing a desired reaction on the substrate 303. A BP: H (F) film, which is a polycrystalline semiconductor film having the following characteristics, is formed. An exhaust pump 315 controls the pressure in the film forming chamber 301 monitored by the pressure gauge 309 by adjusting the opening of the throttle valve 314.

First, a Corning # 7059 glass substrate 303 of 2 inches × 2 inches and a thickness of 0.8 mm was set in the substrate holding cassette 302, and BP: H (F) film sample No. 1
1 to 20 were prepared. A part of the obtained sample was cut out, and the results of the same evaluation and measurement as performed by the method (1) described above are shown in Table 4.

From these results, in this method, by changing the amount of H ₂ gas and / or HF gas introduced into the film formation chamber 301, the hydrogen atom content and / or the fluorine atom content in the deposited film, and furthermore, the average It was found that the crystal grain size can also be controlled. Sample prepared without introducing H ₂ gas and HF gas
In No. 11 and sample No. 12 prepared by introducing 1 sccm of H ₂ gas and 1 sccm of HF gas, hydrogen radicals and fluorine radicals are not present in the plasma, or both are present in a very small amount, The composition ratio between B atoms and P atoms does not satisfy the stoichiometric ratio, the distribution state is localized and non-uniform, the crystal orientation is random, and the average crystal grain size is small. However, in Samples Nos. 13 to 18, the composition ratio of B atoms and P atoms satisfied the stoichiometric ratio with an increase in the introduction amount of the H ₂ gas and the HF gas, the distribution state was improved, and the average crystallinity was improved. The particle size also increased, and a tendency was observed to contain appropriate amounts of hydrogen atoms and fluorine atoms. further,
Samples increased both flow rate of HF gas and H ₂ gas No.19,20
In the case of, the hydrogen radicals and fluorine radicals existing in the plasma became excessive, so that the average crystal grain size decreased and the hydrogen atom content and the fluorine atom content tended to increase.

According to the experiment performed in parallel with this experiment, the hydrogen atom content and the slight amount were changed due to changes in parameters such as substrate temperature, pressure, high-frequency power, sputter gas (Ar) flow rate, distance between target and substrate, and target material. Although the control of the fluorine atom content and the average crystal grain size were possible, the controllability was inferior to the controllability by the change of the introduction amount of the H ₂ gas and / or the F ₂ gas and the HF gas described above.

From the above, it became clear that the amounts of hydrogen radicals and fluorine radicals existing in the reaction system play an important role in forming the deposited film.

(3) Plasma CVD Method In this method, a source gas containing B atoms, a source gas containing P atoms, a H ₂ gas and / or a H ₂ gas, so that mixing is performed in a reaction space of a film formation chamber in which a substrate is placed. Alternatively, HF gas or F ₂ gas is introduced, high-frequency power is applied to a cathode electrode installed in the film formation chamber to form plasma by glow discharge in the reaction space, and the gas introduced therein is decomposed. , Polymerization, radicalization, ionization, etc. to cause a chemical interaction, on the substrate heated and held in the film forming chamber
A semiconductor deposited film composed of BP: H (F) is formed.

This will be specifically described with reference to a schematic diagram of the deposited film forming apparatus shown in FIG.

Reference numeral 401 denotes a film forming chamber having means for performing the method of the present invention, and a substrate 403 is held on a substrate holding cassette 402;
It can move on the substrate transfer jig 406. A thermocouple 404 is used for monitoring when the temperature of the substrate 403 is heated and held by the heater 405. Reference numeral 413 denotes a load lock chamber, which has a built-in substrate transfer jig 406 and can vacuum transfer the substrate via a gate valve 407. Reference numeral 416 denotes a film formation chamber which is effectively used when a semiconductor layer formed using a material different from that formed in the film formation chamber 401 is stacked, and is similar to that provided in the film formation chamber 401. Or other different film forming means (not shown).

A cathode electrode 412 is supplied with high-frequency power from a high-frequency power supply 410 via a matching box 411, and the source gas introduced from the gas introduction pipes 408, 409 is turned into plasma. Precursors generated in the plasma, hydrogen radicals,
Fluorine radicals, various ions and the like reach the substrate 403 while undergoing a chemical interaction to form a BP: H (F) film, which is a semiconductor film having desired characteristics. Reference numeral 415 denotes an exhaust pump, which controls the pressure in the film forming chamber 401 monitored by the pressure gauge 417 by adjusting the opening of the throttle valve 414.

First, a Corning # 7059 glass substrate 403 having a size of 2 inches × 2 inches and a thickness of 0.8 mm was set in a substrate holding cassette 402, and BP: H (F) film sample No. 21 was formed under the film forming conditions shown in Table 5.
~ 30 were made.

The source gases (A), (B) and (C) were introduced into the film forming chamber 401 from a cylinder (not shown) via the gas introduction pipe 408 or 409.

A part of the obtained sample was cut out and measured and evaluated in the same manner as in the above-mentioned method (1). The results are shown in Table 6.

From these results, in the present method, the hydrogen atom content and / or the fluorine content in the deposited film is changed by changing the introduction amount of the H ₂ gas and / or the HF gas as the source gas (C) into the film formation chamber 401. It has been found that the atomic content and also the average crystal grain size can be controlled. In Sample Nos. 21 to 23, H
_Since the introduction of ₂ gas and HF gas is not performed, or even if at least one is introduced, the flow rate is small,
The deposited film formed not only has an amorphous structure,
The distribution of B atoms and P atoms is not uniform due to the influence of the remaining CH ₃ (methyl group), and the hydrogen atom content due to the —CH ₃ group is large. Sample No. 24-28
In, the crystal orientation appears as the H ₂ gas and / or HF gas increases, the composition ratio of B atoms and P atoms satisfies the stoichiometric ratio, the distribution state is improved, and the average crystal grain size increases. However, there was a tendency that appropriate amounts of hydrogen atoms and fluorine atoms were contained. Sample No. 2 with an increased H ₂ gas flow rate
At 9,30, the average crystal grain size tended to decrease due to excess hydrogen radicals in the plasma.

According to the experiment performed in parallel with this experiment, slight changes in parameters such as the substrate temperature, pressure, high-frequency power, flow ratio and type of source gases (A), (B), and (C), distance between electrodes, etc. Although it was possible to control the hydrogen atom content and / or the fluorine atom content, and further the average crystal grain size,
It was inferior to the controllability by the change of the H ₂ gas and / or HF gas introduction amount.

From the above, it became clear that the amounts of hydrogen radicals and fluorine radicals existing in the reaction system play an important role in forming the deposited film.

Experiment B. Examination of the relationship between the size of the average crystal grain size in the deposited film, the content of hydrogen atoms, and the content of fluorine atoms as required, and various properties of the deposited film First, light irradiation of the deposited film In order to evaluate the characteristic deterioration by the method, a part of the sample Nos. 1 to 30 prepared by the method (1) described above was cut out, and a comb-shaped electrode of Cr was deposited on each of them, and the AM-1 light was irradiated for 8 hours. (100 mW / cm ²⁾ change rate .DELTA..sigma electrical conductivity before and after the irradiation sigma was measured _{(Δσ = σ e / σ i} , σ i:: an initial value, sigma _e values after 8 hours), a sample of .DELTA..sigma ≧ 0.95 About ○, 0.95
Samples with <Δσ ≦ 0.9 were evaluated as Δ, and samples with Δσ <0.9 were evaluated as ×, and the results are shown in Table 7. Next, in order to evaluate impurities contained in the deposited film, sample Nos. 1 to
Cut out a portion of 30 and place it in the cryostat
Photoluminescence was measured by irradiating a UV lamp (1 KW) at a temperature of 7.7 K. The evaluation method is based on the ratio ΔI (ΔI = I _S / I _R ) of the spectrum intensity I _S from another sample to the spectrum intensity I _R emerging from the sample No. 11 and the number of the samples. Is ○, 0.3 <ΔI ≦ 0.
The sample of 7 was evaluated as 試 料, and the sample with ΔI> 0.7 was evaluated as ×, and the results are shown in Table 7. Next, in order to evaluate the surface smoothness of the deposited film, a part of the sample Nos. 1 to 30 was also cut out, and the surface was scanned with an FE-SEM (field emission scanning electron microscope: S-900 manufactured by Hitachi, Ltd.). Observation of the fine structure of the irregularities, the uniformity of the crystal grain size is good, the surface is rough, for samples without pinholes, ○, crystal grains are not observed, the distribution is uneven, the surface is rough, Samples having observed pinholes and the like were evaluated as x, and the results are shown in Table 7. Furthermore, these results were compared with ◎, ○, △, ×
The results were comprehensively evaluated in stages, and are summarized in Table 7.

From the above, it was determined that the deposited film sample having a rating of ○ or more had at least various properties suitable for use in devices such as solar cells, and the physical property values of these deposited films were measured. Is 0.5 atomic% to 7 atomic%, and the fluorine content is 0 atomic% to 3 atomic if necessary.
%, The average crystal grain size was found to be in the range of 50 ° to 800 °, and it was found that setting and controlling the physical property values within these numerical ranges formed a deposited film constituting an electronic device having desired characteristics. It turns out that this is a necessary condition for performing.

Experiment C. Study on Valence Electron Control of BP: H (F) Film (1) N-type Doping Under the film formation conditions shown in Table 1 in A- (1), n-type valence electron control atoms were used. Se (CH ₃ ) ₂ (hereinafter abbreviated as DMSe) as a source gas containing a certain Se atom is packed in a hub ring device, and He is bubbled as a carrier gas.
Sample No. 31 was prepared in exactly the same manner except that it was introduced into the activation chamber 208 together with the raw material gas (A) at a flow rate of 2.4 × 10 ⁻¹⁰ mol / min.
~ 40 were made.

Under the film forming conditions shown in Table 3 of A- (2), DMSe was bubbled using He gas as a carrier gas, and the film forming chamber 301 was sputtered with a sputtering gas at a flow rate of 4.8 × 10 ⁻¹¹ mol / min. Sample no.
41-50 were made.

Further, under the film forming conditions shown in Table 5 of A- (3) above, DMSe was bubbled using He gas as a carrier gas, and a film forming chamber was formed together with the raw material gas (A) at a flow rate of 1.2 × 10 ⁻¹⁰ mol / min. Sample No.
51 to 60 were prepared.

Samples Nos. 31 to 60 produced in this manner
In addition to the same measurements and evaluations as those performed in the sections B and B, the conductivity type was evaluated by a thermoelectromotive force measurement method. As a result, Sample Nos. 4-1 to 1 obtained a comprehensive evaluation of
Sample No. corresponding to the film forming conditions of No. 0, No. 13 to 18, and No. 25 to 29
For 34 to 40, No. 43 to 48, and No. 55 to 59, almost no change was observed in any of the evaluation items, and in particular, hydrogen atom content, fluorine atom content, average crystal grain size, change in conductivity. And the photoluminescence showed good reproducibility, and the conductivity type showed n-type.

Therefore, in the present invention, the hydrogen atom content is 0.
5 atomic%-7 atomic%, fluorine atom content is 0 atomic%
It has been found that good n-type doping can be performed by controlling the average crystal grain size to within the range of 50 to 800 at%.

(2) P-type doping Under the film forming conditions shown in Table 1 in A- (1) above, Zn (CH ₃ ) ₂ (Zn (CH ₃ ) ₂ (raw material gas containing Zn atom which is a p-type valence electron controlling atom) Hereafter abbreviated as DMZn) in a bubbling device, and bubbling with He as a carrier gas.
Sample No. 61 was prepared in exactly the same manner except that it was introduced into the activation chamber 208 together with the raw material gas (A) at a flow rate of 4.3 × 10 ⁻¹⁰ mol / min.
~ 70 were made.

Under the film forming conditions shown in Table 3 of A- (2) above, DMZn was bubbled using He gas as a carrier gas, and a film forming chamber was formed together with a sputtering gas at a flow rate of 6.8 × 10 ⁻¹¹ mol / min. Sample N was prepared in exactly the same way except that it was introduced into 301.
o.71 to 80 were prepared.

Further, under the film forming conditions shown in Table 5 of A- (3) above, DMZn was bubbled using He gas as a carrier gas, and the raw material gas (A) was formed at a flow rate of 2.4 × 10 ⁻¹⁰ mol / min. Samples Nos. 81 to 90 were prepared in exactly the same manner except that the sample No. was introduced into the membrane chamber 401.

Sample Nos. 61 to 90 produced in this manner
In addition to the same measurements and evaluations as those performed in the sections B and B, the conductivity type was evaluated by a thermoelectromotive force measurement method. As a result, Sample Nos. 4-1 to 1 obtained a comprehensive evaluation of
Sample No. corresponding to the film forming conditions of No. 0, No. 13 to 18, and No. 25 to 29
In 64 to 70, No. 73 to 78, and No. 85 to 89, almost no change was observed in any of the evaluation items, in particular, hydrogen atom content, fluorine atom content, average crystal grain size, change in conductivity. And the photoluminescence showed good reproducibility, and the conductivity type was p-type.

Therefore, in the present invention, the hydrogen atom content is 0.
5 atomic%-7 atomic%, fluorine atom content is 0 atomic%
It has been found that good p-type doping can be performed by controlling the average crystal grain size within the range of 50 to 800 at 3 atomic%.

Summary of Experimental Results From the above results, the following was understood. That is, in the process of forming the deposited film, the presence of an appropriate amount of hydrogen radicals improves the crystal orientation of the deposited film and increases the average crystal grain size. In addition, the presence of fluorine radicals as required promotes the film formation reaction. Furthermore, the distribution state of B atoms and P atoms in the film is also improved and uniform, and specific atoms are not clustered. The hydrogen radicals and / or fluorine radicals not only act on the film formation, but also contain an appropriate amount in the deposited film so as to terminate dangling bonds, and play an important role in improving various characteristics of the film. Will be fulfilled. For example, when irradiation with strong light is performed for a long time, a film containing no hydrogen atoms or fluorine atoms at all, or a very small amount or even an excessive amount of hydrogen atoms and fluorine atoms is unstable. Side reactions due to external factors such as bond dissociation and hydrolysis are promoted, and changes in the film structure and composition, the increase in dangling bonds due to the elimination of hydrogen atoms and / or fluorine atoms, etc. cause the initial film structure state to change. A change, that is, deterioration occurs. On the other hand, a hydrogen atom
0.5 atomic%-7 atomic%, fluorine atom 0 atomic%-3 atomic
When the atoms are contained in the deposited film in the amount of omic%, these atoms terminate dangling bonds that may be present in the crystal grains, or dangling bonds that are said to be abundant in the crystal grain boundaries. By terminating, the so-called crystal defect state density is reduced, and at the same time, the stress generated structurally is reduced, and a film excellent in electrical, optical and mechanical properties is obtained. Therefore, since a high-quality film is formed stably without being doped, p-type and n-type doping can be easily and reliably achieved.

In the present invention, the elements used to control the BP: H (F) film to be n-type valence electrons include elements of Group VIA of the periodic table, that is, O, S, Se, and Te. , Se and Te are preferably used. On the other hand, the elements used for p-type valence electron control are elements of group IIB of the periodic table, namely, Zn, Cd,
Hg is mentioned, and among them, Zn and Cd are preferably used.

Specifically, as a compound containing a group IIB element, Zn
_{(CH 3) 2, Zn (} C 2 H 5) 2, Zn (OCH 3) 2, Zn (OC 2 H 5) 2, Cd
_{(CH 3) 2, Cd (} C 2 H 5) 2, Cd (C 3 H 7) 2, Cd (C 4 H 9) 2, Hg (C
H ₃ ) ₂ , Hg (C ₂ H ₅ ) ₂ , Hg (C ₆ H ₅ ) ₂ , Hg [C≡ (C ₆ H ₅ )] ₂
Examples of compounds containing a VIA group element include NO, N ₂ O, CO ₂ , CO, H ₂ S, SCl ₂ , S ₂ Cl ₂ , SOCl ₂ , and SO ₂ C
_{l 2, SeCl 4, Se 2} Cl 2, Se 2 Br 2, SeOCl 2, Se (CH 3) 2, Se (C
_{2 H 5) 2, TeCl 2} , Te (CH 3) 2, Te (C 2 H 5) may be mentioned _2.

Of course, these raw materials may be used alone or in combination of two or more. When these raw materials are in a liquid or solid state at normal temperature and normal pressure, bubbling is performed using an inert gas such as Ar or He as a carrier gas using a bubbling device, and then used in a gasified state or heated and sublimated. A sublimate is transported and used using a furnace with an inert gas such as Ar or He as a carrier gas.

Further, the elements of group A of the periodic table IV, namely, C, Si, Ge, S
n and Pb can be used as valence electron controlling atoms. That is, when these atoms replace B atoms, they become n-type, and when these atoms replace P atoms, they become p-type. Also,
When both atoms are substituted, they may be neutralized, but show either n-type or p-type conductivity depending on the difference in the substitution rate. Among them, Si, Ge, and Sn are preferably used.

Specifically, CH ₄ , C ₂ H ₆ , C ₂ H ₄ , C ₂ H ₂ , C ₃ H ₈ , C ₃ H ₆ , C
_{3 H 4, CF 4, (} CF 2) 5, (CF 2) 6, (CF 2) 4, C 2 F 6, C
_{3 F 8, CHF 3, CH} 2 F 2, CCl 4, (CCl 2) 5, CBr 4, (CB
_{r 2) 5, C 2 Cl} 6, C 2 Br 6, CHCl 3, CH 2 Cl 2, CHI 3, CH 2 I 2, C
₂ Cl ₃ F ₃ , C ₂ H ₃ F ₃ , C ₂ H ₂ F ₄ , SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , (Si
_{H 2) 4, (SiH 2} ) 5, (SiH 2) 6, SiF 4, (SiF 2) 5, (Si
F ₂ ) ₆ , (SiF ₂ ) ₄ , Si ₂ F ₆ , Si ₃ F ₈ , SiHF ₃ , SiH ₂ F ₂ , SiC
_{l 4, (SiCl 2) 5} , SiBr 4, (SiBr 2) 5, Si 2 Cl 6, Si 2 B
r ₆ , SiHCl ₃ , SiH ₂ Cl ₂ , SiHBr ₃ , SiHI ₃ , Si ₂ Cl ₃ F ₃ , Si ₂ H
_{3 F 3, Si 2 H 2} F 4, Si 2 H 3 Cl 3, Si 2 H 2 Cl 4, GeH 4, Ge 2 H 6, GeF
_{4, (GeF 2) 5,} (GeF 2) 6, (GeF 2) 4, Ge 2 F 6, Ge 3 F 8,
GeHF ₃ , GeH ₂ F ₂ , GeCl ₄ , (GeCl ₂ ) ₅ , GeBr ₄ , (GeBr ₂ )
_{5, Ge 2 Cl 6, Ge} 2 Br 6, GeHCl 3, GeH 2 Cl 2, GeHBr 3, GeH
I ₃ , Ge ₂ Cl ₃ F ₃ , Ge ₂ H ₃ F ₃ , Ge ₂ H ₃ Cl ₃ , Ge ₂ H ₂ F ₄ , Ge ₂ H ₂ C
_{l 4, SnH 4, SnCl 4} , SnBr 4, Sn (CH 3) 4, Sn (C 2 H 5) 4, Sn
(C ₃ H ₇ ) ₄ , Sn (C ₄ H ₉ ) ₄ , Sn (OCH ₃ ) ₄ , Sn (OC ₂ H ₅ ) ₄ , Sn
_{(I-OC 3 H 7)} 4, Sn (t-OC 4 H 9) 4, Pb (CH 3) 4, Pb (C 2 H
₅ ) ₄ , Pb (C ₄ H ₉ ) _{4 and the} like.

Of course, these raw materials can be used alone or in combination of two or more.

When the raw material is in a gaseous state under normal temperature and normal pressure, the amount introduced into the film formation space or the activation space is controlled by a mass flow controller or the like, and in a liquid state, a rare gas such as Ar or He is used. Alternatively, hydrogen gas is used as a carrier gas, and gasification is performed using a bubbler whose temperature can be controlled as necessary.If the gas is in a solid state, a rare gas such as Ar or He or a hydrogen gas is used as a carrier gas to heat the sublimation furnace. And the amount introduced is controlled mainly by the flow rate of the carrier gas and the furnace temperature.

Examples of the raw material containing a B atom used in the methods (1) and (3) of the present invention include B ₂ H ₆ , B ₄ H
_{10, B 5 H 9, B} 5 H 11, B 6 H 10, B 6 H 12, B 6 H 14 , etc. _{borohydride, BF 3, BCl 3, BBr} 3 , etc. of boron halide, B (CH ₃ )
_{3 and the} like. As the raw material containing P atoms, specifically, PH ₃ , P ₂ H ₄ , PF ₃ , PF ₅ , PCl ₃ , PCl
_{5, PBr 3, PBr 5,} P (CH 3) 3, P (C 2 H 5) 3, P (C 3 H 7) 3, P (C
_{4 H 9) 3, P (} OCH 3) 3, P (OC 2 H 5) 3, P (OC 3 H 7) 3, P (OC
_{4 H 9) 3, P 2} O 5, POCl 3, PO (OCH 3) 3, PO (OC 2 H 5) 3, PO (O
C ₃ H ₇ ) ₃ , PO (OC ₄ H ₉ ) _{3 and the} like.

Of course, these raw materials can be used alone or in combination of two or more.

When the raw material is in a gaseous state under normal temperature and normal pressure, the amount introduced into the film formation space or the activation space is controlled by a mass flow controller or the like, and in a liquid state, a rare gas such as Ar or He is used. Alternatively, using a hydrogen gas as a carrier gas, gasification is performed using a bubbler capable of controlling the temperature as necessary, and when in a solid state, a heating sublimation furnace using a rare gas such as Ar or He or hydrogen gas as a carrier gas is used. It is used for gasification, and the amount introduced is controlled mainly by the carrier gas flow rate and the furnace temperature.

According to the method of the present invention (1) to (3), BP: H (F)
In forming the film, the substrate temperature in any method is preferably 50 ° C to 600 ° C, more preferably 50 ° C to 450 ° C.
° C, optimally between 100 ° C and 400 ° C. The internal pressure at the time of film formation in the methods (1) and (3) of the present invention is preferably 1 × 10 ⁻⁴ Torr to 50 Torr,
More preferably 5 × 10 ⁻³ Torr to 10 Torr, optimally 1 × 10 Torr
^It is desirable to set to ^-3 Torr to 5 Torr. on the other hand,
In the method (2), preferably 1 × 10 ⁻⁵ Torr to 1
× 10 ^-1 Torr, more preferably 1 × 10 ^-4 Torr to 1 × 10 ^-2 To
Preferably set to rr.

As described above, the methods (1) to (3) of this embodiment are performed by the deposited film forming apparatus having the configuration shown in FIGS. 2 to 4, but are not limited to these configurations. Not something.

Next, the configuration of the photovoltaic element of the present invention will be described.
In configuring a photovoltaic element using a pin heterojunction, when light is incident from the p-type semiconductor layer side, when the p-type semiconductor layer is extremely thin, the amount of light absorbed by the layer is extremely small, Most of the incident light can be absorbed by the i-type semiconductor layer, and a large photocurrent is expected to be taken out.

However, reducing the thickness of the p-type semiconductor layer has limitations in physical and electrical characteristics, and several tens of thousands in film forming technology.
A thickness of about several hundreds of mm is necessary, and the amount of light absorption here cannot be ignored depending on the band gap of the p-type semiconductor layer used.

Therefore, when A-Si: H or A-SiC: H that absorbs light on the relatively short wavelength side and generates photocarriers is used as the i-type semiconductor layer, the light absorption in the p-type semiconductor layer is particularly reduced. By suppressing this, a significant improvement in the extracted photocurrent is achieved. Therefore, it is necessary that the p-type semiconductor layer be made of a semiconductor material having a wide band gap.

On the other hand, in the case of using a semiconductor material having a wide band gap for the p-type semiconductor layer and / or the n-type semiconductor layer in the pin heterojunction photovoltaic device, a high open-circuit voltage (Voc) is obtained.
Can be generated, and a high photoelectric conversion efficiency can be achieved by a synergistic effect with the above-described effect.

BP: H having p-type or n-type conductivity according to the present invention
(F) The film is present in the film as long as it contains a specific amount of hydrogen atoms and / or fluorine atoms and has an average crystal grain size within a predetermined value range, particularly in terms of its composition and structure. Since defects are extremely reduced and the characteristics are greatly improved as compared with the conventional BP film, it can be used as a material suitable for achieving the above object.

Of course, the above concept is also applied to the case where light is incident from the n-type semiconductor layer side. Furthermore, in a so-called tandem type or triple type photovoltaic element in which two or three pin heterojunction type photovoltaic elements are stacked, the p-type photovoltaic element located closest to the light incident side is the p-type according to the present invention. Alternatively, the effect of using a BP: H: F film having an n-type conductivity type as a p-type and / or n-type semiconductor layer is great.

Further, since light of a relatively long wavelength side can be absorbed, even when A-SiGe: H or μc-Si: H capable of originally obtaining a large photocurrent is used as the i-type semiconductor layer, the BP of the present invention having a large band gap is used. : Electron generated in the i-type semiconductor layer by the so-called back surface field effect caused by the conduction band gap between the p-type semiconductor layer composed of the H (F) film and the i-type semiconductor layer having a narrow band gap. Reverse diffusion at the -i junction interface is prevented, and an increase in photocurrent can be expected.

As described above, the photovoltaic element of the present invention can obtain a large photocurrent, and its photoelectric conversion rate is greatly improved as compared with the conventional one.
Therefore, the present invention can provide excellent photoelectric conversion efficiency both for a light source having a relatively large wavelength component such as a fluorescent lamp and a light source having a large wavelength component such as an incandescent lamp. Can be suitably used as a power source for consumer equipment.

In addition, when the tandem type or the triple type is used as described above, the deterioration of characteristics due to use is suppressed to a level that does not hinder practical use. The element can be suitably used also as a solar cell for a power supply system by solar power generation.

Hereinafter, examples of the layer configuration of the photovoltaic device of the present invention will be described.
The photovoltaic device of the present invention is not limited by this.

FIGS. 1A and 1B are diagrams schematically showing a typical example of a layer configuration when a semiconductor deposited film according to the present invention is used as a photovoltaic element of the present invention.

In the example shown in FIG. 1A, the lower electrode 10
2, n-type semiconductor layer 103, i-type semiconductor layer 104, p-type semiconductor layer 1
05 is a photovoltaic element 100 in which a transparent electrode 106 and a collecting electrode 107 are formed in this order. In this photovoltaic element, it is assumed that light is incident from the transparent electrode 106 side.

In the example shown in FIG. 1B, a transparent electrode 106, a p-type semiconductor layer 105, an i-type semiconductor layer 104, an n-type semiconductor layer 103, and a lower electrode 102 are deposited and formed in this order on a translucent support 101. This is the photovoltaic element 100 obtained. In this photovoltaic element, it is assumed that light is incident from the transparent support 101 side.

The example shown in FIG. 1 (C) is a so-called so-called pin-type photovoltaic element 111, 112, 113 using three types of semiconductor layers having different band gaps and / or layer thicknesses as i-layers. This is a toy pull type photovoltaic element 120. 101
Denotes a support, and the lower electrode 102, the n-type semiconductor layer 103, the i-type semiconductor layer 104, the p-type semiconductor layer 105, the n-type semiconductor layer 114, i
Semiconductor layer 115, p-type semiconductor layer 116, n-type semiconductor layer 117,
The i-type semiconductor layer 118, the p-type semiconductor layer 119, the transparent electrode 106, and the current collecting electrode 107 are laminated in this order, and it is assumed that light is incident from the transparent electrode 106 side in this photovoltaic element. .

In any of the photovoltaic elements, the n-type semiconductor layer and the p-type semiconductor layer can be used in a different order of lamination according to the purpose.

Hereinafter, the configurations of these photovoltaic elements will be described.

Support The support 101 used in the present invention may be single-crystalline or non-single-crystalline, and furthermore, they may be conductive or electrically insulating. Alternatively, it may be electrically insulating. Furthermore, they may be translucent. Moreover,
They may be light-transmitting or non-light-transmitting, but need to be light-transmitting when light enters from the support 101 side. It is.
As specific examples thereof, Fe, Ni, Cr, Al, Mo, Au, Nb, Ta, V, T
metals such as i, Pt, Pb or alloys thereof, such as brass,
Stainless steel and the like.

In addition to these, there may be mentioned films or sheets of synthetic resin such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, etc., glass, ceramics and the like.

In addition, as a single crystalline support, Si, Ge, C, NaCl, KCl, Li
F, GaSb, InAs, InSb, Gap, MgO, CaF ₂ , BaF ₂ , α-Al ₂ O ₃ etc. sliced from a single crystal and processed into a wafer, etc., and the same substance or lattice on them A material obtained by epitaxially growing a material having a constant close to that is exemplified.

The shape of the support can be plate-shaped, long belt-shaped, cylindrical, or the like having a smooth surface or an uneven surface depending on the purpose and application, and the thickness thereof is such that a desired photovoltaic element can be formed. It is determined as appropriate, but when flexibility is required as the photovoltaic element, or when light is incident from the side of the support, as much as possible within the range where the function as the support is sufficiently exhibited. Can be thin. However, the thickness is usually 10 μm or more from the viewpoints of production and handling of the support, mechanical strength and the like.

Electrode In the photovoltaic element of the present invention, an appropriate electrode is selected and used depending on the configuration of the element. Examples of these electrodes include a lower electrode, an upper electrode (transparent electrode), and a collecting electrode. (However, the upper electrode referred to here indicates an electrode provided on the light incident side, and the lower electrode indicates an electrode provided opposite to the upper electrode with a semiconductor layer interposed therebetween.) The electrodes are described in detail below.

(I) Lower Electrode As the lower electrode 102 used in the present invention, the surface to which light for generating photovoltaic light is irradiated is different depending on whether or not the material of the support 101 is translucent (for example, When the support 101 is a non-translucent material such as a metal, light for photovoltaic generation is irradiated from the transparent electrode 106 side as shown in FIG. 1 (A)). Location is different.

Specifically, in the case of a layer configuration as shown in FIGS. 1A and 1C, it is provided between the support 101 and the n-type semiconductor layer 103. However, when the support 101 is conductive, the support can also serve as the lower electrode. However, if the sheet resistance is high even if the support 101 is conductive, the electrode is used as a low-resistance electrode for extracting current or for the purpose of increasing the reflectance on the support surface and effectively using incident light. 102 may be installed.

In the case of FIG. 1 (B), a light-transmitting support 101 is used, and light enters from the support 101 side. Therefore, for the purpose of current extraction and light reflection at the electrode, A lower electrode 102 is provided facing the support 101 with the semiconductor layer interposed therebetween.

When an electrically insulating material is used as the support 101, a lower electrode 102 is provided between the support 101 and the n-type semiconductor layer 103 as an electrode for extracting current.

As electrode materials, Ag, Au, Pt, Ni, Cr, Cu, Al, Ti, Zn, Mo,
Metals such as W or alloys thereof are mentioned, and thin films of these metals are formed by vacuum evaporation, electron beam evaporation, sputtering, or the like. Further, care must be taken that the formed metal thin film does not become a resistance component with respect to the output of the photovoltaic element, and the sheet resistance is preferably 50Ω or less, more preferably 10Ω or less.

Although not shown in the figure, a diffusion preventing layer such as conductive zinc oxide may be provided between the lower electrode 102 and the n-type semiconductor layer 103. The effect of the diffusion prevention layer is not only to prevent the metal element constituting the electrode 102 from diffusing into the n-type semiconductor layer, but also to provide a small resistance value so that the lower electrode provided with the semiconductor layer interposed therebetween. To prevent short-circuiting caused by a defect such as a pinhole between the transparent electrode 106 and the transparent electrode 106;
In addition, there can be obtained an effect that multiple interference by a thin film is generated and incident light is confined in a photovoltaic element.

(Ii) Upper electrode (transparent electrode) The transparent electrode 106 used in the present invention has a light transmittance of 85% or more in order to efficiently absorb light from the sun or a white fluorescent lamp into the semiconductor layer. The sheet resistance is desirably 100Ω or less so that the output of the photovoltaic element does not become a resistance component. As a material having such properties, Sn
Metal oxides such as O ₂ , In ₂ O ₃ , ZnO, CdO, Cd ₂ SnO ₄ , ITO (In ₂ O ₃ + SnO ₂ ), and metals such as Au, Al, Cu etc. Metal thin film and the like. The transparent electrode is laminated on the p-type semiconductor layer 105 in FIG.
In FIG. 1B, since they are stacked on the substrate 101, it is necessary to select ones having good adhesion to each other. These production methods include resistance heating evaporation,
An electron beam heating vapor deposition method, a sputtering method, a spray method, or the like can be used, and is appropriately selected as desired.

(Iii) Current collecting electrode The current collecting electrode 107 used in the present invention is a transparent electrode 1
06 is provided on the transparent electrode 106 for the purpose of reducing the surface resistance value. Ag, Cr, Ni, Al, Au, Ti, Pt, C
Examples thereof include thin films of metals such as u, Mo, and W or alloys thereof.
These thin films can be stacked and used. Also,
The shape and area are appropriately designed so that the amount of light incident on the semiconductor layer is sufficiently ensured.

For example, it is desirable that the shape is uniformly spread over the light receiving surface of the photovoltaic element, and that the area is preferably 15% or less, more preferably 10% or less with respect to the light receiving area.

Further, as a sheet resistance value, preferably 50Ω or less,
More preferably, it is desirably 10Ω or less.

i-type semiconductor layer As the semiconductor material constituting the i-type semiconductor layer suitably used in the present invention, A-Si: H, A-Si: F, A-Si: H:
F, A-SiC: H, A-SiC: F, A-SiC: H: F, A-SiGe: H, A-SiGe:
F, A-SiGe: H: F, poly-Si: H, poly-Si: F, poly-Si: H: F.

In the photovoltaic element of the present invention, desired characteristics can be obtained by a combination of these i-type semiconductor layers and the aforementioned p-type and / or n-type semiconductor layers composed of BP: H (F) of the present invention. Things. Regarding this point, the following experiment D
Will be further clarified.

Experiment D In this experiment, in addition to the constituent materials of the i-type semiconductor layer, A-Si, A-SiC, A-S
iGe, poly-Si is also used as an i-type semiconductor layer, and a BP: H (F) film of the present invention or a conventional BP film is used as a p-type and / or n-type semiconductor layer. A photovoltaic device (sample Nos. 91 to 109) was fabricated, and AM-1 light (100 mW / cm)
² ) Under irradiation, short-circuit current (Isc) and open-circuit voltage (Voc) were measured and evaluated.

The layer configuration of the photovoltaic element is the configuration shown in FIG. 1B. The support 101 is made of quartz glass, the transparent electrode 106 is an ITO film formed by a sputtering method, and the lower electrode 102 is an electron beam heating. Light was incident from the support 101 side using an Ag thin film formed by the method.

The BP: H (F) film as the p-type semiconductor layer of the present invention is the above-mentioned sample No. 76, and the BP: H (F) film as the n-type semiconductor layer of the present invention is used.
(F) The film was formed under the same film forming conditions as those of Sample No. 36 described above.

The BP film as the p-type semiconductor layer by the conventional method
It was manufactured under the same film forming conditions as those formed in No. 71. An A-Si: H film as an n-type semiconductor layer according to a conventional method was formed by a known plasma CVD method.

The method for forming the i-type semiconductor layer is described in the above-mentioned “Study on the method for forming a BP: H (F) film into which hydrogen atoms and, if necessary, fluorine atoms are introduced” (1) to (3). )
The source gas containing B atoms and P
Use a source gas containing Si atoms, a source gas containing C atoms or a source gas containing Ge atoms instead of a source gas containing atoms, or use Si, SiC, SiGe, etc. instead of a target consisting of BP etc. May be used. Therefore, the amount of hydrogen atoms and / or fluorine atoms contained in the i-type semiconductor layer is appropriately adjusted and controlled by changing various parameters such as the H ₂ gas flow rate and the HF gas flow rate.
Accordingly, as an apparatus for forming an i-type semiconductor layer, a deposited film forming apparatus having basically the same configuration as that shown in FIGS. 2 to 4 can be used. A detailed method of forming the i-type semiconductor layer will be described in Examples described later. In addition, different semiconductor layers having different material configurations or conduction types can be formed by using the same deposition film forming apparatus and changing the kind of gas to be introduced and the like. It is desirable to provide a deposited film forming apparatus.

Table 8 shows the configurations and evaluation results of various photovoltaic elements.

From these results, when a common semiconductor film is used for the i-type semiconductor layer and the n-type semiconductor layer, the p-type BP: H (F) film of the present invention is used for the p-type semiconductor layer for both Isc and Voc. Is the case where the p-type BP film according to the conventional method is used (sample Nos. 91 to 9).
3,97-99 and sample Nos. 104-109), all of which exhibited better property improvement. Furthermore, when the n-type BP: H (F) film of the present invention was used for the n-type semiconductor layer, an improvement in Voc and Isc was observed. On the other hand, even when the p-type BP: H (F) film of the present invention is used, A-Si, A-Sic, A-SiGe, which contains neither hydrogen nor fluorine and is formed by a sputtering method as an i-type semiconductor layer.
When poly-Si was used (sample Nos. 100 to 103), characteristics that could withstand use could not be obtained.

Hereinafter, for strict distinction, amorphous silicon containing both or one of hydrogen and fluorine used in the present invention, polycrystalline silicon, an alloy of amorphous silicon and carbon, and an alloy of amorphous silicon and germanium are used. A-Si: H: F, A
−Si: H, A−Si: F, poly−Si: H: F, poly−Si: H, poly−Si: F,
A-SiC: H: F, A-SiC: H, A-SiC: F, A-SiGe: H: F, A-SiGe:
H, A-SiGe: F, and the case containing neither hydrogen nor fluorine are simply described as A-Si, poly-Si, A-SiC, A-SiGe.

From the above experimental results, p provided by the present invention
In forming a pin heterojunction type photovoltaic device using a n-type and / or n-type BP: H (F) film, a semiconductor material preferably used as an i-type semiconductor layer is A-Si: H, A-Si : F, A−
Si: H: F, A-SiC: H, A-SiC: F, A-SiC: H: F, A-SiGe: H, A-S
iGe: F, A-SiGe: H: F, poly-Si: H, poly-Si: F, poly-Si:
It turned out to be H: F.

In the present invention, as a means for forming a good pin heterojunction, it is desirable that the formation of the n-type semiconductor layer, the formation of the i-type semiconductor layer, and the formation of the p-type semiconductor layer be performed continuously in a vacuum. Specifically, when the semiconductor layers are formed continuously in the same deposition film forming apparatus, or when the respective semiconductor layers are formed using different apparatuses, the respective deposition film forming apparatuses are connected via a gate valve or the like. For example, after forming an n-type semiconductor layer with the first deposited film forming apparatus, the substrate on which the n-type semiconductor layer is formed is transferred to a second deposited film forming apparatus under vacuum conditions, and the second deposited film is formed. An i-type semiconductor layer is formed by a film forming apparatus, and the substrate formed up to the i-type semiconductor layer is transported to a third deposited film forming apparatus under vacuum conditions. What is necessary is just to form a p-type semiconductor layer.

〔Example〕

Hereinafter, the photovoltaic device of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 The pin heterojunction type photovoltaic element shown in FIG. 1A was formed by using the deposition film forming apparatus having the structure shown in FIG. Produced by the procedure.

After placing a stainless steel substrate 101 having a size of 50 mm × 50 mm in a sputtering apparatus (not shown) and evacuating it to 10 ⁻⁵ Torr or less, the substrate 101
An Ag thin film of about 1000 ° serving as the lower electrode 102 was deposited thereon.
The substrate 101 is taken out, and the lower electrode is placed on a substrate holding cassette 202 on a substrate transfer jig 206 in the load lock chamber 212.
The surface on which 102 was deposited was fixed facing downward in the figure, and the inside of the load lock chamber 212 was evacuated to a pressure of 10 ^-5 Torr or less by an exhaust pump (not shown). During this time, the deposition chamber 201 is
Due to 21, the gas is exhausted to a pressure of 10 ^-5 Torr or less. When the pressures in both chambers became substantially equal, the gate valve 207 was opened, the substrate holding cassette 202 was moved into the film forming chamber 201 using the substrate transfer jig 206, and the gate valve 207 was closed again.

Next, heating was performed by the heater 205 so that the surface temperature of the substrate 203 became 220 ° C. When the substrate temperature stabilizes,
25 sccm of Si ₂ F ₆ gas and PH ₃ (Si
While mixing the 4000ppm dilution) gas 10sccm at F _4, it was introduced into the activation chamber 208 which is heated to keep 700 ° C. from the gas supply pipe 214 in an electric furnace 211. At the same time, each of 100sccm and 50s He gas and H ₂ gas stored in the gas cylinder (not shown)
The mixture is mixed at a flow rate of ccm.
Introduced inside. Next, the opening degree of the exhaust valve 220 was adjusted, and 300 W microwave power was supplied from the 2.45 GHz microwave generator 212 into the activation chamber 209 while maintaining the internal pressure of the film forming chamber 201 at 0.3 Torr. Deposition chamber 2 from transport pipes 217 and 218
The precursor, hydrogen radicals, and the like introduced into 01 were immediately reacted to deposit and form an A-Si: H: F film 103 as an n-type semiconductor layer. After depositing and forming an n-type A-Si: H: F film having a thickness of 400 °, the introduction of the source gas and the supply of the microwave power were stopped, and the inside of the film forming chamber 201 was evacuated to 10 ^-5 Torr or less by the exhaust pump 221. Next, the substrate 203 formed up to the n-type semiconductor layer 103 was moved using the substrate transfer jig 206 to the film formation chamber 222 evacuated to 10 ⁻⁵ Torr with the same configuration as the film formation chamber 201. . Hereinafter, since the configuration inside the film forming chamber 222 is the same as that of the film forming chamber 201, it will be described using the same drawing numbers as those shown in FIG.

Next, the introduction of PH ₃ gas as a source gas for doping was stopped, Si ₂ F ₆ gas was introduced at 30 sccm, and microwave power was increased to 400
An A-Si: H: F film 104 was formed as an i-type semiconductor layer at 3500 ° under the same conditions as above except that W was used.

After the film formation, the introduction of the gas and the supply of the microwave power were stopped, and the inside of the film formation chamber 222 was evacuated to 10 ^-5 Torr.

Next, the substrate 203 formed up to the i-type semiconductor layer 104 was transferred to a film formation chamber (not shown) having the same configuration as the film formation chamber 201 by the same operation as described above. Therefore, using a He gas of 20 sccm as a carrier gas, a B (C ₂ H ₅ ) ₃ / Zn (CH ₃ ) ₂ = 10 ⁴ : 1 solution filled in a bubbling device (not shown) is used as a solution of 2.5 × 10 ^-4 mol. /
Bubbling was performed at a flow rate of min and introduced into the activation chamber 208 via the gas supply pipe 214. The microwave power of 60 W was immediately supplied from the microwave generator 211 into the activation chamber 208. At the same time, activation chamber 21 in which 5.5 sccm of PF ₅ gas is heated and held at 500 ° C. in electric furnace 213 through gas supply pipe 216.
0, and a mixed gas of H ₂ gas 8 sccm and He gas 40 sccm is introduced into the activation chamber 209 via the gas supply pipe 215, and the microwave power of 320 W is supplied from the microwave generator 212 into the activation chamber 209. I put it in. At this time, the pressure in the film forming chamber 201 is 60 mTor.
Controlled to r. Activation chamber 20 via transport pipes 217, 218, 219
The precursors, hydrogen radicals, and the like generated in 8,209,210 are introduced into the film forming chamber 201 and immediately cause a chemical reaction, and the transport pipe 218
A BP: H: F film was formed as a p-type semiconductor layer on a substrate 203 provided at a position 8 cm from the gas discharge port and heated and maintained at 210 ° C.

After laminating a 200 ° p-type BP: H: F film on the i-type semiconductor layer 104, a load lock chamber (not shown) for taking out the substrate holding cassette 202 through the gate valve 207 by the substrate transfer jig 206. After cooling, the substrate 203 on which the n-type, i-type and p-type semiconductor layers were deposited was taken out. The substrate 203 was placed in a vacuum deposition apparatus in which a deposition boat filled with metal particles of In and Sn at a weight ratio of 1: 1 was set and evacuated to 10 ⁻⁵ Torr or less. In an oxygen atmosphere of about 10 ⁻³ Torr, an ITO thin film as the transparent electrode 106 was deposited by about 700 °. The substrate heating temperature at this time was 170 ° C. After cooling, the substrate 203 is taken out, a permalloy mask for forming a current collecting electrode pattern is brought into close contact with the upper surface of the transparent electrode 106, placed in a vacuum evaporation apparatus, and evacuated to 1 × 10 ⁻⁵ Torr or less, and then subjected to a resistance heating method. Then, Ag was vapor-deposited to a thickness of about 0.8 μm to form a comb-shaped current collecting electrode 107. The photovoltaic element thus formed was referred to as Element No. 1.

 The characteristics of the device No. 1 were evaluated as follows.

AM-1 light (100 mW / cm ² ) from the transparent electrode 106 side of device No. 1
Open voltage Voc and short-circuit current Isc when irradiating
The relative value of the output when the AM-1 light was irradiated through a 400 nm interference filter (relative value to the measured value of the device manufactured in Comparative Example 1 described below under the same conditions) was measured.
Table 9 shows the measurement results.

Separately, using a quartz glass substrate, BP as a p-type semiconductor layer using the same method and procedure as described above:
The H: F film was formed alone. With respect to the obtained deposited film, the contents of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in the above-mentioned [Experiment]. The measurement results are shown in Table 9.

Example 2 In this example, a BP: H: F film as a p-type semiconductor layer was formed using the deposited film forming apparatus shown in FIG. 3 in the pin heterojunction photovoltaic device in Example 1.

Therefore, in the pin heterojunction type photovoltaic element shown in FIG. 1A, the operation is the same as that of the first embodiment up to the formation of the substrate 101, the lower electrode 102, the n-type semiconductor layer 103, and the i-type semiconductor layer 104. I went.

The substrate 303 fixed to the substrate holding cassette 302 and deposited up to the i-type semiconductor layer is deposited by the substrate transport jig 306 into the film forming chamber 30.
1 and heat the substrate 303 while keeping it at 10 ^-5 Torr or less.
Heat at 305 to 220 ° C, and when the substrate temperature stabilizes,
Sputtering was started under the conditions shown in the table and the i-type semiconductor layer was
A BP: H: F film 105 as a 200 ° p-type semiconductor layer was deposited on 104.

After the film formation, the substrate 303 is moved from the film formation chamber 301 to a take-out load lock chamber (not shown), cooled, taken out, and subjected to the same operation and method as in the first embodiment.
The ITO film as 106 is 700 mm, and a comb-shaped Ag thin film as the current collecting electrode 107 is deposited thereon at 0.8 μm to form an element No. 2,
The same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, using a quartz glass substrate, a BP: H: F film as a p-type semiconductor layer was deposited under the same film forming conditions as shown in Table 10. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 3 In this example, a BP: H: F film as a p-type semiconductor layer was formed using the deposited film forming apparatus shown in FIG. 4 in the pin heterojunction type photovoltaic element in Example 1.

Therefore, in the pin heterojunction type photovoltaic element shown in FIG. 1A, the operation is the same as that of the first embodiment up to the formation of the substrate 101, the lower electrode 102, the n-type semiconductor layer 103, and the i-type semiconductor layer 104. I went.

The substrate 403 fixed to the substrate holding cassette 402 and deposited up to the i-type semiconductor layer 104 is deposited by the substrate transport jig 406 into the film forming chamber 40.
1 and heat the substrate 403 while keeping it at 10 ^-5 Torr or less.
Heat at 405 to 230 ° C, and when the substrate temperature stabilizes,
Under the conditions shown in the table, the source gas (A), the source gas (B), and the source gas (C) were supplied from the introduction pipes 408 and 409 to the film forming chamber 40, respectively.
1 and adjust the opening of the exhaust valve 414 to form the deposition chamber 401.
Was maintained at 0.8 Torr while monitoring the pressure with a pressure gauge 417.
The high-frequency power supply 410 is connected to the cathode electrode 412 via the matching circuit 411, and 13.56 M
A high frequency power of 70 Hz was immediately applied to start film formation.
Thus, the A-Si: H: F film 10 as an i-type semiconductor layer
A BP: H: F film 105 as a p-type semiconductor layer was deposited on the substrate 4 at a thickness of 200 °.

After completion of the film formation, the substrate 403 is moved from the film formation chamber 401 to a load lock chamber (not shown) for removal, cooled, taken out, and subjected to the same operation and method as in the first embodiment.
An ITO film as No. 6 was 700 °, and a comb-shaped Ag thin film as the current collecting electrode 107 was deposited thereon at 0.8 μm to obtain a device No. 3, and the same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, a BP: H: F film as a p-type semiconductor layer was deposited using a quartz glass substrate under the same film forming conditions as shown in Table 11. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 4 In this example, an A-SiC: H: F film was used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction type photovoltaic device in Example 1. Therefore, in the pin heterojunction type photovoltaic element shown in FIG. 1A, the operations up to the formation of the substrate 101, the lower electrode 102, and the n-type semiconductor layer 103 were performed in exactly the same manner as in Example 1.

Next, the n-type semiconductor layer is transferred to a film forming chamber (the structure is the same as that of the film forming chamber 201, and will be described with a common drawing number) which is completely evacuated to 10 ^-5 Torr with the same structure as the film forming chamber 201. The substrate 203 formed up to this point is opened with the gate valve 207 opened, transferred using the substrate transfer jig 206, the gate valve 207 is closed, and the film forming chamber is opened.
The substrate 203 was heated to 220 ° C. by the heater 205 while maintaining the pressure in the inside at 10 ⁻⁵ Torr, and when the substrate temperature became stable,
Under the conditions shown in Table 12, the source gas (A), the source gas (B), and the source gas (C) were respectively supplied to the gas supply pipes 214, 215,
From 216, they are introduced into the activation chambers 208, 209, 210 to be excited species,
The excited species was introduced into the film forming chamber 201 through the transport pipes 217, 218, and 219 to start film formation. Table 12 shows the excitation energy generators and excitation conditions used.

Thus, the A-Si: H: F film as the n-type semiconductor layer
An A-SiC: H: F film 104 as an i-type semiconductor layer 104
Å Deposited.

Then, the BP: H: F film serving as the p-type semiconductor layer 105 was formed at a thickness of 200 °, the ITO film serving as the transparent electrode 106 was provided at a thickness of 700 °, and the comb serving as the current collecting electrode 107 was formed in the same manner as in Example 1. A device No. 4 was formed by depositing a tooth-shaped Ag thin film at 0.8 μm, and the solar cell characteristics were evaluated in the same manner as in Example 1. The evaluation results are shown in Table 9.

Separately, a BP as a p-type semiconductor layer was formed using a quartz glass substrate under the same film forming conditions as in Example 1.
An H: F film was deposited. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 5 In this example, an A-SiGe: H: F film was used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device in Example 1. Therefore, in the pin heterojunction type photovoltaic element shown in FIG. 1A, the operations up to the formation of the substrate 101, the lower electrode 102, and the n-type semiconductor layer 103 were performed in exactly the same manner as in Example 1.

Next, the n-type semiconductor layer is transferred to a film forming chamber (the structure is the same as that of the film forming chamber 201, and will be described with a common drawing number) which is completely evacuated to 10 ^-5 Torr with the same structure as the film forming chamber 201. The substrate 203 formed up to this point is opened by opening the gate valve 207, transferred using the substrate transfer jig 206, and closed by the gate valve 207, and the film forming chamber is opened.
Heating substrate 203 while maintaining the pressure in 201 at 10 ^-5 Torr
Heat to 220 ° C with 205.
Under the conditions shown in the table, the source gas (A), the source gas (B), and the source gas (C) were respectively supplied to gas supply pipes 214, 215, and 21.
From 6, the excited species were introduced into the activation chambers 208, 209 and 210 to be excited species, and the excited species were introduced into the film formation chamber 201 via the transport pipes 217, 218 and 219 to start film formation. Table 13 shows the excitation energy generators and excitation conditions used.

Thus, the A-Si: H: F film as the n-type semiconductor layer
An A-SiGe: H: F film 104 as an i-type semiconductor layer is
Å Deposited.

Then, the BP: H: F film serving as the p-type semiconductor layer 105 was formed at a thickness of 200 °, the ITO film serving as the transparent electrode 106 was provided at a thickness of 700 °, and the comb serving as the current collecting electrode 107 was formed in the same manner as in Example 1. An element No. 5 was formed by depositing a tooth-shaped Ag thin film of 0.8 μm, and the same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, a BP as a p-type semiconductor layer was formed using a quartz glass substrate under the same film forming conditions as in Example 1.
An H: F film was deposited. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 6 In this example, a poly-Si: H: F film was used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction type photovoltaic device in Example 1. Therefore, in the pin heterojunction type photovoltaic element shown in FIG. 1A, the operations up to the formation of the substrate 101, the lower electrode 102, and the n-type semiconductor layer 103 were performed in exactly the same manner as in Example 1.

Next, the n-type semiconductor layer is transferred to a film forming chamber (the structure is the same as that of the film forming chamber 201, and will be described with a common drawing number) which is completely evacuated to 10 ^-5 Torr with the same structure as the film forming chamber 201. The substrate 203 formed up to this point is opened by opening the gate valve 207, transferred using the substrate transfer jig 206, and closed by the gate valve 207, and the film forming chamber is opened.
Heating substrate 203 while maintaining the pressure in 201 at 10 ^-5 Torr
Heat to 220 ° C with 205, and when the substrate temperature stabilizes,
Under the conditions shown in the table, the source gas (A) and the source gas (B) were supplied from the gas supply pipes 214 and 215 to the activation chambers 208 and 209, respectively.
Then, the excited species were introduced into the inside of the film formation chamber 201 via the transport pipes 217 and 218 to start film formation. Table 14 shows the used excitation energy generators and excitation conditions.

Thus, the A-Si: H: F film as the n-type semiconductor layer
A poly-Si: H: F film 104 as an i-type semiconductor layer 104
Å Deposited.

Then, the BP: H: F film serving as the p-type semiconductor layer 105 was set at 200 °, the ITO film serving as the Mykei electrode 106 was set at 700 °, and the current collecting electrode 107 was used as the p-type semiconductor layer 105 by the same operation and method as in Example 1. A comb-shaped Ag thin film was deposited at 0.8 μm to obtain a device No. 6, and the same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, a BP as a p-type semiconductor layer was formed using a quartz glass substrate under the same film forming conditions as in Example 1.
An H: F film was deposited. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 7 In this example, a pin heterojunction type photovoltaic element having the structure shown in FIG. 1B was manufactured using a glass substrate instead of a stainless steel substrate, and the same characteristic evaluation as in Example 1 was performed. Was done. The manufacturing method is described below.

Transparent electrode 106 on Corning # 7059 glass substrate 101
An ITO film was formed at 500 ° by the same resistance heating method as in Example 1, and a BP: H: F film as a p-type semiconductor layer was formed on the ITO film by 200 ° by the same operation and method as in Example 1. Deposited. Subsequently, an A-Si: H: F film as an i-type semiconductor layer was deposited at 3500 ° by the same operation and method as in Example 1. Further, A as an n-type semiconductor layer is formed by the same operation and method as in Example 1.
-An Si: H: F film was deposited at 400 Å.

Next, an Ag thin film as the lower electrode 102 was deposited to a thickness of 0.5 μm to obtain a device No. 7, and the same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, a BP as a p-type semiconductor layer was formed using a quartz glass substrate under the same film forming conditions as in Example 1.
An H: F film was deposited. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Example 8 In this example, the BP: H: F film of the present invention was used instead of the A-Si: H: F film for the n-type semiconductor layer in the pin heterojunction photovoltaic device in Example 1. . Therefore, as shown in FIG.
The operation up to the formation of the substrate 101 and the lower electrode 102 in the pin heterojunction photovoltaic element was performed in exactly the same manner as in Example 1.

Next, the film formation chamber is completely evacuated to 10 ⁻⁵ Torr with the same structure as the film formation chamber 201 (the structure is the same as that of the film formation chamber 201 and will be described with a common drawing number). The formed substrate 203 is opened by opening the gate valve 207, transferred using the substrate transfer jig 206, and closed by the gate valve 207, and the film forming chamber is opened.
Heating substrate 203 while maintaining the pressure in 201 at 10 ^-5 Torr
Heat to 220 ° C with 205.
Under the conditions shown in the table, the source gas (A), the source gas (B), and the source gas (C) were respectively supplied to gas supply pipes 214, 215, and 21.
From 6, the excited species were introduced into the activation chambers 208, 209 and 210 to be excited species, and the excited species were introduced into the film formation chamber 201 via the transport pipes 217, 218 and 219 to start film formation. Table 15 shows the used excitation energy generators and excitation conditions.

Thus, a BP: H: F film as the n-type semiconductor layer 103 was deposited on the lower electrode 102 at a thickness of 400 °.

Then, the A-Si: H: F film as the i-type semiconductor layer 104 was formed at 3500 ° by the same operation and method as in Example 1.
200 ° of BP: H: F film as the p-type semiconductor layer 105, transparent electrode 10
Element No. 8 was obtained by depositing an ITO film as 700 mm and a comb-shaped Ag thin film as the current collecting electrode 107 at 0.8 μm to obtain a device No. 8, and the same solar cell characteristics as in Example 1 were evaluated. The evaluation results are shown in Table 9.

Separately, a BP as a p-type semiconductor layer was formed using a quartz glass substrate under the same film forming conditions as in Example 1.
An H: F film and a BP: H: F film as an n-type semiconductor layer were deposited under the film forming conditions shown in Table 15. For the obtained deposited film, the content of hydrogen atoms and fluorine atoms in the film and the average crystal grain size were measured in the same manner as in Example 1. The measurement results are shown in Table 9.

Embodiment 9 This embodiment is directed to a BP formed by a conventional sputtering method in place of the A-Si: H: F film as the n-type semiconductor layer in the pin heterojunction photovoltaic device in Embodiment 1. A membrane is used. Accordingly, in the pin heterojunction photovoltaic element shown in FIG. 1A, the formation of the substrate 101 and the lower electrode 102 and the formation of the i-type semiconductor layer 104, the p-type semiconductor layer 105, the transparent electrode 106, and the current collecting electrode 107 Was performed in exactly the same manner as in Example 1.

The formation of the BP film as the n-type semiconductor layer 103 was performed under the conditions shown in Table 16 using the deposition film forming apparatus shown in FIG.

The solar cell thus formed was designated as element No. 9,
The solar cell characteristics and the like were evaluated. Table 17 shows the evaluation results.

Embodiment 10 In this embodiment, a pin heterojunction type photovoltaic device according to Embodiment 1 is replaced by an A-SiGe film formed by a plasma CVD method instead of an A-Si: H: F film as an n-type semiconductor layer. : H: F film is used. Accordingly, in the pin heterojunction photovoltaic element shown in FIG. 1A, the formation of the substrate 101 and the lower electrode 102 and the formation of the i-type semiconductor layer 104, the p-type semiconductor layer 105, the transparent electrode 106, and the current collecting electrode 107 Was performed in exactly the same manner as in Example 1.

The A-SiGe: H: F film as the n-type semiconductor layer 103 was formed using the deposition film forming apparatus shown in FIG. 4 under the conditions shown in Table 18.

The solar cell thus formed was designated as element No. 10, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 11 In this embodiment, an A-SiC film formed by a plasma CVD method in place of the A-Si: H: F film as the n-type semiconductor layer in the pin heterojunction photovoltaic device in the first embodiment is described. : H: F film is used. Accordingly, in the pin heterojunction photovoltaic element shown in FIG. 1A, the formation of the substrate 101 and the lower electrode 102 and the formation of the i-type semiconductor layer 104, the p-type semiconductor layer 105, the transparent electrode 106, and the current collecting electrode 107 Was performed in exactly the same manner as in Example 1.

The formation of the A-SiC: H: F film as the n-type semiconductor layer 103 is the fourth step.
The deposition was performed under the conditions shown in Table 19 using the deposited film forming apparatus shown in the figure.

The solar cell thus formed was designated as element No. 11, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Example 12 In this example, a GaAs film formed by a sputtering method was used instead of the A-Si: H: F film as the n-type semiconductor layer in the pin heterojunction photovoltaic device in Example 1. ing. Accordingly, in the pin heterojunction photovoltaic element shown in FIG. 1A, the formation of the substrate 101 and the lower electrode 102 and the formation of the i-type semiconductor layer 104, the p-type semiconductor layer 105, the transparent electrode 106, and the current collecting electrode 107 Was performed in exactly the same manner as in Example 1.

The GaAs film as the n-type semiconductor layer 103 was formed using the deposition film forming apparatus shown in FIG. 3 under the conditions shown in Table 20.

The solar cell thus formed was designated as element No. 12, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 13 This embodiment uses an A-Si: H film instead of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device of the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The formation of the A-Si: H film as the i-type semiconductor layer 104 was performed using the deposition film forming apparatus shown in FIG. 4 under the conditions shown in Table 21.

The solar cell thus formed was designated as element No. 13, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 14 In the present embodiment, an A-SiGe: H film is used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic element in the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The formation of the A-SiGe: H film as the i-type semiconductor layer 104 was performed using the deposition film forming apparatus shown in FIG. 4 under the conditions shown in Table 22.

The solar cell thus formed was designated as element No. 14, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 15 This embodiment uses an A-SiC: H film instead of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device of the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The formation of the A-SiC: H film as the i-type semiconductor layer 104 was performed using the deposition film forming apparatus shown in FIG. 4 under the conditions shown in Table 23.

The solar cell thus formed was designated as element No. 15, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 16 In this embodiment, an A-Si: F film is used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device of the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The i-type A-Si: F film was formed using the deposition film forming apparatus shown in FIG. 3 under the conditions shown in Table 24.

The solar cell thus formed was designated as element No. 16, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 17 In this embodiment, an A-SiGeC: H film is used in place of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device of the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The i-type A-SiGeC: H film was formed using the deposition film forming apparatus shown in FIG. 4 under the conditions shown in Table 25.

The solar cell thus formed was designated as element No. 17, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Embodiment 18 In this embodiment, a poly-Si: H film is used instead of the A-Si: H: F film as the i-type semiconductor layer in the pin heterojunction photovoltaic device of the eighth embodiment.

Therefore, except that the i-type semiconductor layer 104 was formed, a solar cell was formed by the same operation and method as in Example 8.

The i-type poly-Si: H film was formed using the deposition film forming apparatus shown in FIG. 3 under the conditions shown in Table 26.

The solar cell thus formed was designated as element No. 18, and the solar cell characteristics and the like were evaluated. The evaluation results
The results are shown in Table 17.

Example 19 This example is directed to a pin heterojunction photovoltaic device shown in FIG. 1B, in which 103 is an n-type semiconductor layer, 105 is a p-type semiconductor layer, and p-type semiconductor layer 105 and i-type semiconductor layer. Layer 104 A
This is an element in which an n-type semiconductor layer 103 is made of a BP: H: F film of the present invention, which is made of a Si: H: F film and light is incident from the glass substrate 101 side.

The i-type semiconductor layer 104 is formed by the same operation and method as those formed in the eighth embodiment, and the p-type semiconductor layer 105 is formed by the n-type semiconductor layer 105 in the first embodiment. A
-Si: H: BF ₃ in place of PH ₃ at F film formation conditions (H ₂ at 4000
ppm dilution) was introduced in exactly the same manner and method except that 35 sccm was introduced.

Further, the formation of the substrate 101, the lower electrode 102, and the transparent electrode 106 was performed by exactly the same operation and method as in Example 7.

The solar cell thus formed was designated as element No. 19, and the solar cell characteristics and the like were evaluated. The evaluation results
It is shown in Table 27.

Embodiment 20 This embodiment is directed to a pin heterojunction type photovoltaic device shown in FIG. 1B in which 103 is an n-type semiconductor layer, 105 is a p-type semiconductor layer, and p-type semiconductor layer 105 is A-SiC. : H: F: membrane, i
This is an element in which the type semiconductor layer 104 is formed of an A-Si: H: F film, and the n-type semiconductor layer 103 is formed of a BP: H: F film of the present invention so that light enters from the glass substrate 101 side.

The i-type semiconductor layer 104 is formed in the same operation and method as those formed in the eighth embodiment, and the p-type semiconductor layer 105 is formed in the n-type semiconductor layer 105 in the eleventh embodiment. A
-SiC: H: BF at F film formation conditions in place of PH _{3 3} (H ₂ at 400
Except for introducing 30 sccm (0 ppm dilution), it was formed in exactly the same operation and method.

Further, the formation of the substrate 101, the lower electrode 102, and the transparent electrode 106 was performed by exactly the same operation and method as in Example 7.

The solar cell thus formed was designated as element No. 20, and the solar cell characteristics and the like were evaluated. The evaluation results
It is shown in Table 27.

Example 21 In this example, in the pin heterojunction photovoltaic element shown in FIG. 1B, 103 is an n-type semiconductor layer, 105 is a p-type semiconductor layer, and p-type semiconductor layer 105 is a ZnTe film. , I-type semiconductor layer 104 is an A-Si: H: F film, and n-type semiconductor layer 103 is
This is an element formed of a P: H: F film and receiving light from the glass substrate 101 side.

The i-type semiconductor layer 104 was formed in Example 1 and the n-type semiconductor layer 103 was formed by exactly the same operation and method as those formed in Example 8.

The p-type ZnTe film was formed using the deposition film forming apparatus shown in FIG. 3 under the conditions shown in Table 28.

The formation of the substrate 101, the lower electrode 102, and the transparent electrode 106 was performed by exactly the same operation and method as in Example 7.

The solar cell thus formed was designated as element No. 21, and the solar cell characteristics and the like were evaluated. The evaluation results
It is shown in Table 27.

Embodiment 22 In this embodiment, in the pin heterojunction photovoltaic device shown in FIG. 1B, 103 is an n-type semiconductor layer, 105 is a p-type semiconductor layer, and p-type semiconductor layer 105 is a conventional method. With BP membrane,
The i-type semiconductor layer 104 is an A-Si: H: F film, the n-type semiconductor layer 103 is a BP: H: F film of the present invention, and light is incident from the glass substrate 101 side. .

The i-type semiconductor layer 104 was formed in Example 1 and the n-type semiconductor layer 103 was formed by exactly the same operation and method as those formed in Example 8.

The p-type BP film was formed using the deposition film forming apparatus shown in FIG. 3 under the conditions shown in Table 29.

The formation of the substrate 101, the lower electrode 102, and the transparent electrode 106 was performed by exactly the same operation and method as in Example 7.

The solar cell thus formed was designated as element No. 22, and the solar cell characteristics and the like were evaluated. The evaluation results
It is shown in Table 27.

Embodiment 23 In this embodiment, a so-called triple formed by stacking three pin heterojunction photovoltaic elements using three types of semiconductor layers having different band gaps as i-layers as shown in FIG. A photovoltaic device 120 was produced.

From the substrate 101 to the p-type semiconductor layer 105, a first-layer photovoltaic element 111 in which the i-type semiconductor layer is composed of an A-SiGe: H: F film is manufactured in exactly the same operation and method as in the fifth embodiment. did.

Next, an n-type semiconductor layer 114, an i-type semiconductor layer 115, and a p-type semiconductor layer 116 are deposited by exactly the same operation and method as in Example 1, and the i-type semiconductor layer is formed of an A-Si: H: F film. A second layer photovoltaic element 112 was produced. However, at this time, the thickness of the i-type semiconductor layer was 3000 °. Subsequently, the n-type semiconductor layer 117, the i-type semiconductor layer 118, and the p-type
A type semiconductor layer 119 was deposited, and a third layer photovoltaic element 113 in which the i-type semiconductor layer was formed of an A-SiC: H: F film was manufactured. However, at this time, the thickness of the i-type semiconductor layer was 2500 °. Furthermore,
In the same operation and method as in Example 1, an ITO film as the transparent electrode 106 was deposited at 700 Å and a comb-shaped Ag thin film as the current collecting electrode 107 was deposited at 0.8 μm to obtain an element No. 23, and evaluation of solar cell characteristics and the like Was done. Table 30 shows the measurement results.

Comparative Example 1 In this comparative example, an A-Si: H: F film having a thickness of 200 mm was used instead of the BP: H: F film as the p-type semiconductor layer 105 in the pin heterojunction photovoltaic device of Example 1. A photovoltaic element for comparison was produced in exactly the same operation and method except that was used.
Here, the p-type semiconductor layer 105 was formed using a deposition film forming apparatus having the same configuration as that shown in FIG.
i ₂ F ₆ gas 30sccm and BF ₃ (4000 ppm diluted with SiF ₄₎ gas 8scc
m while mixing with the electric furnace 211 from the gas supply pipe 214.
And introduced into the activation chamber 208 which is heated and maintained at 700 ° C. At the same time, He gas and H ₂ gas stored in a cylinder (not shown) were mixed at flow rates of 120 sccm and 50 sccm, respectively, and introduced into the activation chamber 209 from the gas supply pipe 215. Immediately, microwave power of 320 W is supplied from the microwave generator 212 to the activation room 2.
09 and the film formation was started. At this time, the internal pressure of the film forming chamber 201 was set to 0.35 Torr. In this way, the comparative element N
o.24 was prepared and the solar cell characteristics and the like were evaluated. Table 31 shows the measurement results.

Comparative Example 2 The same operation and method as in Example 1 were performed except that H ₂ gas was not introduced when the p-type semiconductor layer 105 was deposited using the pin heterojunction photovoltaic device. element
No. 25 was produced. In the first embodiment, the p-type semiconductor layer 1
Element No. 26 for comparison was produced in exactly the same operation and method except that the flow rate of H ₂ gas was set to 0.5 sccm when depositing 05. Evaluation of the solar cell characteristics of these devices was performed in the same manner as in Example 1. Table 31 shows the measurement results.

Comparative Example 3 When depositing a p-type semiconductor layer in Example 1, B ₂ H ₆
/ Zn (CH ₃ ) ₂ = 10 ⁴ : 1 solution bubbling amount is 5.0 × 10 ^-4 mol
/ min, to prepare a device No.27 for comparison in the same operation and method except that the 15sccm the flow rate of the PF ₅ gas was evaluated such as a solar cell characteristics. Table 31 shows the measurement results.

Comparative Example 4 The device shown in FIG. 3 was used instead of the A-Si: H: F film as the i-type semiconductor layer 104 in the pin heterojunction photovoltaic device in Example 1, and the results are shown in Table 32. A photovoltaic element for comparison was produced by exactly the same operation and method except that an A-Si film, an A-SiC film, and an A-SiGe film produced under the indicated film forming conditions were used. .28,29,30. Table 31 shows the measurement results of the solar cell characteristics and the like.

Comparative Example 5 In the triple type photovoltaic element 120 of Example 23, only the p-type semiconductor layer 119 of the third layer photovoltaic element 113 was replaced with the BP: H: F film of the present invention in Comparative Example 1. Same as made,
A photovoltaic device for comparison having exactly the same configuration except that the film was changed to a p-type A-Si: H: F film was fabricated, and was designated as device No. 31. Table 30 shows the evaluation results of the solar cell characteristics and the like.

<Characteristics Evaluation Results of Each Sample> The measurement results of the solar cell characteristics and the like of each element manufactured in Examples 1 to 23 and Comparative Examples 1 to 5 are ninth, 17, 27, 30, and 3
Shown in Table 1.

The characteristic evaluation items for the photovoltaic element were AM-1 light (10
0mW / cm ² ) Open-circuit voltage (Voc), short-circuit current (Is
c) There is a relative value of the output of each element under the AM-1 irradiation transmitted through a 400 nm interference filter (relative value to the output of the element manufactured in Comparative Example 1 under the same conditions). The results are shown.

In addition, the p-type and / or n-type BP: H: F film used to constitute each photovoltaic element has a hydrogen atom and fluorine atom content and an average crystal grain size specified in the present invention. The p-type and / or n-type BP: H: F films prepared to confirm that the composition ratio of B atoms and P atoms satisfies the stoichiometric ratio is controlled. The measured values of the content of hydrogen atoms and fluorine atoms, the average crystal grain size, and the composition ratio of B atoms to P atoms are also shown.

Summarizing the above results, in the pin heterojunction photovoltaic devices of Examples 1 to 3, the A-Si: H: F film was used as the n-type semiconductor layer and the i-type semiconductor layer, and the p-type semiconductor layer was A method for forming a BP: H (F) film using a BP: H (F) film in which the content of hydrogen atoms and fluorine atoms and the average crystal grain size in the film of the present invention are controlled to specific ranges. Are variously changed, but A-type is added to the p-type semiconductor layer shown in Comparative Example 1.
Higher open-circuit voltage Voc, higher short-circuit photocurrent Isc, and higher relative output under irradiation with AM-1 light transmitted through a 400 nm interference filter than photovoltaic devices using Si: H: F. It turned out to be a photovoltaic element.

In the fourth embodiment, as the i-type semiconductor layer 104,
The A-SiC: H: F film is used as the i-type semiconductor layer 104 in the fifth embodiment.
In the sixth embodiment, an A-SiGe: H: F film is used. In the sixth embodiment, a poly-Si: H: F film is used as the i-type semiconductor layer 104. did. In each case, although it varied depending on the band gap of the i-type semiconductor layer, it was found that the photovoltaic device was an excellent photovoltaic device having a high Voc or a large Isc as a whole.

In Example 7, a photovoltaic element having a configuration shown in FIG. 1B using a glass substrate was used, and light was incident from the glass substrate side. However, similar to Examples 1 to 3, excellent solar cell characteristics were obtained. was gotten.

In Example 8, the BP: H (F) film of the present invention was used for the n-type semiconductor layer 103 simultaneously with the p-type semiconductor layer 105, but excellent solar cell characteristics were obtained as in Examples 1 to 3. Was done.

On the other hand, the photovoltaic element manufactured in Comparative Example 2 has p
Where the type semiconductor layer had a content of hydrogen atoms and fluorine atoms and a crystal grain size outside the range specified in the present invention,
Low Voc, low Isc, low relative output, Example 1
The solar cell characteristics were far inferior to those of the photovoltaic devices manufactured in Nos. 1 to 3.

In Comparative Example 3, BP: H (F) as a p-type semiconductor layer was used.
When the composition ratio of B atoms and P atoms did not satisfy the stoichiometric ratio in the film, the solar cell characteristics were also inferior to those of the photovoltaic devices manufactured in Examples 1 to 3.

In Comparative Example 4, as the i-type semiconductor layer 104, an A-Si film containing no hydrogen atoms and no fluorine atoms, an A-SiC film, an AS
Although the iGe film was used and the BP: H (F) film specified in the present invention was used as the p-type semiconductor layer, the solar cell characteristics were much higher than those of Examples 3 to 5. Was inferior.

In Examples 9 to 12, BP was used as the n-type semiconductor layer.
Using a film, an A-SiGe: H: F film, an A-SiC: H: F film, and a GaAs film,
A photovoltaic element having the same other configuration as that of Example 1 was examined. In each case, although the band gap of the n-type semiconductor layer was slightly affected, excellent solar cell characteristics having a high Voc or a large Isc were obtained as a whole.

In Examples 13 to 18, a study was conducted in which the composition of the i-type semiconductor layer was changed in the photovoltaic device having the configuration implemented in Example 8. Specifically, A-Si: H film, A-SiGe: H film, A-Si
A photovoltaic element was manufactured using a C: H film, an A-Si: F film, an A-SiGeC: H film, and a poiy-Si: H film. In any case, although there is a change according to the magnitude of the band gap of the i-type semiconductor layer, overall
Excellent solar cell characteristics with high Voc or large Isc were obtained.

In Examples 19 to 22, the photovoltaic element having the configuration shown in FIG. 1B is used. However, the stacking positions of the p-type semiconductor layer and the n-type semiconductor layer are switched, and light is incident from the n-type semiconductor layer side. went. Here, the BP: H (F) film of the present invention is applied to the n-type semiconductor layer,
An A-Si: H: F film was used for the i-type semiconductor layer, and various p-type semiconductor layers having different compositions were used. Specifically, A-Si:
The H: F film, the A-SiC: H: F film, the ZnTe film, and the BP film were examined.Although the effect of the band gap of the p-type semiconductor layer was slightly affected, Voc was generally high or Isc Great and excellent solar cell characteristics were obtained.

The characteristic evaluation item as a photovoltaic element in Example 23 and Comparative Example 5 was Vo under irradiation with AM-1 light (100 mW / cm ² ).
The amount of change in photoelectric conversion efficiency before and after continuous irradiation of c, Isc and AM-1 light for 10 hours (Δη / η ₀ : Δη indicates the amount of change in photoelectric conversion efficiency, η ₀ indicates the initial photoelectric conversion efficiency), The results of these evaluations are shown in Table 30.

From the above results, the BP: H (F) of the present invention was added to the p-type semiconductor layer.
The triple structure photovoltaic element of Example 23 using the film,
It was found that both Voc and Isc were superior to the triple structure photovoltaic element of Comparative Example 5 using the A-Si: H: F film for the p-type semiconductor layer. Regarding the amount of change in photoelectric conversion efficiency, the photovoltaic element in Example 23 is smaller than that in Comparative Example 5. In general, the deterioration phenomenon of the photoelectric conversion efficiency occurs remarkably within 10 hours after the start of continuous irradiation of light, and the change after that is extremely slow. It has been found that the photovoltaic element is not only excellent in initial characteristics, but also a photovoltaic element that can be used for a long time and is highly practical as a solar cell.

[Summary of Effects of the Invention] As described above, the photovoltaic device of the present invention has a high photoelectric conversion efficiency of short wavelength light, and can extract a large short-circuit current (Isc) with a high open-circuit voltage (Voc). In addition, a more inexpensive substrate can be used, and the stacked type can extremely reduce the characteristic deterioration due to use, so that it can be highly practical as a solar cell for a power supply system. .

[Brief description of the drawings]

FIGS. 1A and 1B are schematic cross-sectional views of a typical example of a layer configuration of a photovoltaic device of the present invention. Fig. 1 (C)
FIG. 1 is a schematic sectional view of a layer structure of a stacked photovoltaic device of the present invention. FIG. 2 is a schematic diagram of an example of a deposited film forming apparatus for performing the HRCVD method of the present invention. FIG. 3 is a schematic diagram of an example of a deposited film forming apparatus for performing the reactive sputtering method of the present invention. FIG. 4 is a schematic diagram of an example of a deposited film forming apparatus for performing the plasma CVD method of the present invention. 1, 100, 111, 112, 113 ... photovoltaic element, 101 ... support, 102 ...
Lower electrode, 103, 114 ... n-type semiconductor layer, 104, 115, 118 ... i-type semiconductor layer, 105, 116, 119 ... p-type semiconductor layer, 106 ... transparent electrode, 107 ... current collecting electrode. 2, 3, and 4, 201, 301, 401: film forming chamber, 202, 302, 402: substrate holding cassette, 203, 303, 403: substrate, 204, 304, 404: thermocouple, 205, 30
5,405: heater, 206, 306, 406: substrate transfer jig, 207, 30
7,407… Gate valve, 308,408,409… Gas inlet pipe, 208,
209,210: activation chamber, 211, 212, 213: excitation energy generator, 214, 215, 216: gas supply pipe, 212, 313, 413: load lock chamber, 217, 218, 219: transport pipe, 220, 314, 414: valve, 221, 315, 415: exhaust pump, 222, 316, 416: other film formation chamber, 223, 309, 417: pressure Total, 310,410… High frequency power supply, 31
1,411 matching circuit, 312,412 cathode electrode, 317
…target.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Soichiro Kawakami 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-56-11667 (JP, A) -151374 (JP, A) JP-A-55-124272 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 31/04

Claims (3)

(57) [Claims] 1. A photovoltaic device having a junction structure of a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer, wherein at least the p-type semiconductor layer or the n-type semiconductor layer of the semiconductor layers is provided. Is a polycrystalline BP thin film having an average crystal grain size of 50 to 800 ° containing a hydrogen atom and / or a fluorine atom and a p-type or n-type valence electron controlling atom, and the content of the hydrogen atom Is 0.5 to 7 atomic%, and
A photovoltaic element, wherein the type semiconductor layer is made of a non-single-crystal silicon semiconductor containing hydrogen atoms and / or fluorine atoms. 2. A photovoltaic device having a junction structure of a p-type semiconductor layer, an i-type semiconductor layer, and an n-type semiconductor layer, wherein at least the p-type semiconductor layer or the n-type semiconductor layer of the semiconductor layers is provided. Is a polycrystalline BP thin film having a flat crystal grain size of 50 to 800 ° containing a hydrogen atom and / or a fluorine atom and a p-type or n-type valence electron controlling atom, and the content of the hydrogen atom Is 0.5 to 7 atomic%, and the i-type semiconductor layer is made of a non-single-crystal silicon alloy-based semiconductor containing germanium atoms and / or carbon atoms, and hydrogen atoms and / or fluorine atoms. Photovoltaic element. 3. The photovoltaic device according to claim 1, wherein at least one of the p-type semiconductor layer and the n-type semiconductor layer contains 3 atomic% or less of fluorine atoms.