JP5400322B2 - Silicon-based thin film solar cell and method for manufacturing the same - Google Patents

Description

  The present invention relates to a silicon-based thin film solar cell, and in particular, by arranging a thin layer having a refractive index smaller than that of the photoelectric conversion layer behind the photoelectric conversion layer viewed from the light incident side, The present invention relates to a thin film solar cell that simultaneously exhibits an effect of reducing carrier recombination.

  In recent years, thin film solar cells that require less raw materials to achieve both cost reduction and high efficiency of photoelectric conversion devices have attracted attention and are being developed vigorously. At present, in addition to conventional amorphous thin-film solar cells, crystalline thin-film solar cells have also been developed, and stacked thin-film solar cells called hybrid solar cells in which these are stacked have been put into practical use.

  A thin film solar cell generally includes a first electrode, one or more semiconductor thin film photoelectric conversion units, and a second electrode that are sequentially stacked on a substrate. One photoelectric conversion unit includes an i-type layer sandwiched between a p-type layer and an n-type layer.

  The i-type layer is a substantially intrinsic semiconductor layer and occupies most of the thickness of the photoelectric conversion unit, and the photoelectric conversion action mainly occurs in the i-type layer. For this reason, this i-type layer is usually called an i-type photoelectric conversion layer or simply a photoelectric conversion layer. The photoelectric conversion layer is not limited to the intrinsic semiconductor layer, and may be a layer doped in a small amount of p-type or n-type within a range where loss of light absorbed by the doped impurities does not matter. The photoelectric conversion layer is preferably thicker for light absorption, but if it is thicker than necessary, the cost and time for film formation will increase.

  On the other hand, the p-type and n-type conductive layers serve to generate a diffusion potential in the photoelectric conversion unit, and the open circuit voltage (Voc), which is one of the important characteristics of the thin-film solar cell, depending on the magnitude of this diffusion potential. The value of depends on. However, these conductive layers are inactive layers that do not directly contribute to photoelectric conversion, and light absorbed by impurities doped in the conductive layer results in a loss that does not contribute to power generation. Therefore, it is preferable to keep the p-type and n-type conductive layers as small as possible as long as they are within a range in which a sufficient diffusion potential can be generated.

  For the p-type and n-type conductive layers, the same material as the photoelectric conversion layer may be used. For example, by using a material having a wider band gap than the photoelectric conversion layer, such as silicon carbide for silicon. A technique for forming a new electric field at the interface between the conductive type layer and the photoelectric conversion layer and suppressing recombination of carriers generated along with light absorption at the interface is also widely used.

  Here, the pin (nip) type photoelectric conversion unit or thin film solar cell as described above has its main part regardless of whether the p-type and n-type conductive layers contained therein are amorphous or crystalline. An amorphous photoelectric conversion layer is referred to as an amorphous unit or an amorphous thin film solar cell, and a crystalline photoelectric conversion layer is referred to as a crystalline unit or a crystalline thin film solar cell.

  As a method for improving the conversion efficiency of the thin-film solar cell, there is a method of stacking two or more photoelectric conversion units into a tandem type. In this method, a front unit including a photoelectric conversion layer having a wide band gap is disposed on the light incident side of the thin film solar cell, and a rear unit including a photoelectric conversion layer having a narrow band gap is sequentially disposed behind the front unit. The photoelectric conversion is enabled over a wide wavelength range of the incident light, thereby improving the conversion efficiency of the entire solar cell.

  Among such tandem solar cells, a laminate in which an amorphous photoelectric conversion unit and a crystalline photoelectric conversion unit are stacked is called a hybrid thin film solar cell. For example, the wavelength of light that can be photoelectrically converted by i-type amorphous silicon is up to about 800 nm on the long wavelength side, but i-type crystalline silicon photoelectrically converts light up to a wavelength of about 1100 nm longer than that. Can do.

  However, a thickness of about 0.3 μm or less is sufficient for an amorphous silicon photoelectric conversion layer having a large light absorption coefficient to absorb light sufficiently, but a crystalline silicon photoelectric conversion layer having a small light absorption coefficient is long. In order to sufficiently absorb light having a wavelength, it is preferable to have a thickness of about 1.5 to 3 μm. That is, the crystalline photoelectric conversion layer is usually desired to have a thickness of about 5 to 10 times that of the amorphous photoelectric conversion layer.

  In both the amorphous silicon single-layer thin-film solar cell and the hybrid thin-film solar cell described above, it is desirable to keep the thickness of the photoelectric conversion layer as small as possible from the viewpoint of productivity improvement, that is, cost reduction. For this reason, a structure using a so-called light confinement effect that effectively reflects light of a specific wavelength by arranging a layer having a smaller refractive index than the photoelectric conversion layer behind the photoelectric conversion layer when viewed from the light incident side is common. It is used for.

  Arranged behind the photoelectric conversion layer when viewed from the light incident side is that it is in contact with the photoelectric conversion layer on the back side, or another layer is arranged on the back side of the photoelectric conversion layer, It is arranged on the back side with the layer in between. As a conventional technique, Patent Document 1 discloses, from the light incident side, a translucent first electrode, an amorphous silicon semiconductor thin film (hereinafter simply referred to as a semiconductor thin film), a zinc oxide film having a thickness of less than 1200 mm, and an opaqueness. A structure of a solar cell in which a second electrode (metal electrode) is sequentially laminated is disclosed.

  The zinc oxide film has a function of preventing an increase in absorption loss due to silicide at the interface between the semiconductor thin film and the metal electrode, and there is a difference in refractive index between the zinc oxide film and the semiconductor thin film. Therefore, if the thickness of the zinc oxide film is limited to less than 1200 mm, preferably 300 to 900 mm, it has the effect of improving the reflectance at the semiconductor thin film / zinc oxide film interface, so the short-circuit current density of the solar cell is improved, It is described that the conversion efficiency is improved.

However, since the zinc oxide film is formed by a method such as sputtering or spraying, it is necessary to use equipment different from the semiconductor thin film generally formed by plasma CVD method, which requires equipment cost and production tact. The problem of lengthening occurs. Furthermore, in particular, when a sputtering method is used for forming a zinc oxide film, there is a problem that the performance may be deteriorated due to sputtering damage to the underlying semiconductor thin film.
Japanese Patent Laid-Open No. 2-73672

  The present invention provides a silicon-based thin film with high efficiency and low cost by disposing a silicon-based layer having a refractive index lower than that of the photoelectric conversion layer very thinly behind the crystalline photoelectric conversion layer when viewed from the light incident side. It aims to provide solar cells.

The silicon-based thin film solar cell of the present application has the following configuration.

A silicon-based thin film characterized in that an n-type conductive silicon oxide layer / n-type amorphous silicon interface layer / n-type microcrystalline silicon interface layer are sequentially arranged behind the crystalline photoelectric conversion layer as viewed from the light incident side Solar cell.

The silicon-based thin-film solar cell described above , wherein the n- type conductive silicon oxide layer has a refractive index of 2.7 or less at a wavelength of 600 nm.

The silicon-based thin-film solar cell described above , wherein the most abundant constituent element excluding silicon in the n- type conductive silicon oxide layer is oxygen.

The n- type conductive silicon oxide layer includes the crystalline silicon component in the layer, and the silicon-based thin film solar cell described above .

The silicon-based thin film solar cell described above , wherein the n- type conductive silicon oxide layer has a thickness of 10 nm or less.

The silicon thin film solar cell as described above , wherein the n- type amorphous silicon interface layer has a thickness of 2 nm or more.

The silicon-based thin film solar cell described above , wherein at least one amorphous photoelectric conversion unit and one crystalline photoelectric conversion unit are stacked.

  According to the present invention, there is an effect of improving Voc, which makes it possible to increase conversion efficiency.

  The n-type conductive silicon oxide layer is a layer that is doped n-type with impurities and serves to generate a diffusion potential in the crystalline photoelectric conversion layer and to grow an n-type amorphous silicon layer. By disposing the n-type amorphous layer, a new electric field is generated between the crystalline photoelectric conversion layer and the n-type layer, and the recombination of carriers at the interface can be reduced. Further, by arranging the n-type crystalline silicon interface layer, the contact resistance with the transparent oxide layer arranged in contact with the n-type interface layer can be reduced, and the n-type conductive silicon oxide layer / n-type amorphous silicon is reduced. The diffusion potential in the crystalline photoelectric conversion layer, which may be insufficient with the interface layer alone, can be maintained.

  A silicon-based thin film solar cell as an embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, a transparent electrode layer 2 is formed on a translucent substrate 1. As the translucent substrate 1, a plate-like member or a sheet-like member made of glass, transparent resin or the like is used. The transparent electrode layer 2 is preferably a conductive metal oxide, and specific examples thereof include SnO ₂ and ZnO. The transparent electrode layer 2 is preferably formed using a method such as CVD, sputtering, or vapor deposition. The transparent electrode layer 2 desirably has an effect of increasing the scattering of incident light on the surface thereof. Specifically, it is desirable to have the effect of increasing the scattering of incident light by having fine irregularities.

  An amorphous photoelectric conversion unit 3 is formed on the transparent electrode layer 2. The amorphous photoelectric conversion unit 3 includes an amorphous p-type silicon carbide layer 3pa, a non-doped amorphous i-type silicon photoelectric conversion layer 3ia, and an n-type silicon-based interface layer 3na. A crystalline photoelectric conversion unit 4 is formed on the amorphous photoelectric conversion unit 3. A high-frequency plasma CVD method is suitable for forming the amorphous photoelectric conversion unit 3 and the crystalline photoelectric conversion unit 4 (hereinafter, both units are collectively referred to as a photoelectric conversion unit).

As conditions for forming the photoelectric conversion unit, a substrate temperature of 100 to 300 ° C., a pressure of 30 to 1500 Pa, and a high frequency power density of 0.01 to 0.5 W / cm ² are preferably used. As a raw material gas used for forming the photoelectric conversion unit, a silicon-containing gas such as SiH ₄ or Si ₂ H ₆ or a mixture of these gases and H ₂ is used. As the dopant gas for forming the p-type or n-type layer in the photoelectric conversion unit, B ₂ H ₆ or PH ₃ is preferably used.

The crystalline photoelectric conversion unit 4 includes a crystalline p-type silicon layer 4pc, a crystalline i-type silicon photoelectric conversion layer 4ic, an n-type conductive silicon oxide layer 4on, an n-type amorphous silicon interface layer 4na, and an n-type crystalline silicon layer 4nc. It consists of As a source gas used for forming the n-type conductive silicon oxide layer 4on, a mixed gas of SiH ₄ , H ₂ , CO ₂ , and PH ₃ is suitable. In the configuration of the present invention, the thickness of the n-type conductive silicon oxide layer 4on is preferably set to 15 nm or less. The n-type conductive silicon oxide layer 4on may not contain a crystalline silicon component, but it is more preferred that it is contained.

The refractive index at a wavelength of 600 nm of the n-type conductive silicon oxide layer 4on is preferably 2.7 or less, more preferably 2.5 or less, and particularly preferably 2.1 or less. A film having an n-type conductive silicon oxide layer 4on having a conductivity in the range of 1 × 10 ⁻³ S / cm to 1 × 10 ⁻⁶ S / cm can be used. The n-type conductive silicon oxide layer 4on may have a constant refractive index in the film thickness direction, or the refractive index may change in the middle. Furthermore, the refractive index may be increased or decreased periodically.

  FIG. 1 shows a structure in which the n-type conductive silicon oxide layer 4on is disposed in contact with the back of the crystalline i-type silicon photoelectric conversion layer 4ic as viewed from the light incident side. Another layer such as an n-type silicon layer may be interposed between the conversion layer 4ic and the n-type conductive silicon oxide layer 4on.

  In FIG. 1, an n-type amorphous silicon interface layer 4na is formed on the n-type conductive silicon oxide layer 4on. The n-type conductive silicon oxide layer 4on has an effect as a base layer for forming a high-quality n-type amorphous silicon interface layer 4na without being dragged by the crystallinity of the crystalline i-type silicon photoelectric conversion layer 4ic. Damage to the underlying crystalline silicon layer during sputtering of the ZnO layer that occurs during the process can be prevented.

  As can be seen from the comparison between Examples 1 to 3 and Comparative Example 2, when there is no n-type conductive silicon oxide layer 4on between the crystalline i-type silicon photoelectric conversion layer 4i and the n-type amorphous silicon interface layer 4na, Under the influence of the crystallinity of the crystalline i-type silicon photoelectric conversion layer, the crystallinity of the n-type amorphous silicon interface layer increases and the open circuit voltage decreases. Furthermore, it has the effect of improving the short circuit current. This is because the reflection at the interface between the crystalline i-type silicon photoelectric conversion layer and the n-type conductive silicon oxide layer is increased by the n-type conductive silicon oxide layer having a low refractive index, resulting in a light confinement effect. Conceivable.

The n-type conductive silicon oxide layer 4on is an alloy layer composed of elements such as silicon and oxygen, and generates a sufficient diffusion potential in the photoelectric conversion layer even if it is thin. Therefore, the conductivity of the layer is 1 × 10 ⁻ It is preferably ³ S / cm or less and in the range of 1 × 10 ⁻⁶ S / cm or more, and preferably formed by the same type of manufacturing method as the photoelectric conversion layer, that is, a method such as high-frequency plasma CVD. . The n-type conductive silicon oxide layer contains a crystalline silicon component in the layer in order to obtain the above-described conductivity and reduce the interface resistance with the conductive silicon-based interface layer formed in contact therewith. preferable.

  The n-type conductive silicon oxide layer is a layer having a wider band gap than the photoelectric conversion layer and has few defects due to lattice mismatch at the interface with the photoelectric conversion layer. Acts as a bastion layer. However, the n-type conductive silicon oxide layer itself contains a large amount of elements other than silicon. For this reason, if the n-type conductive silicon oxide layer is a little too thick, carrier recombination in the layer is greatly promoted compared with, for example, a silicon-only conductive layer, and at the obtained interface. The effect of reducing carrier recombination is canceled, and the open circuit voltage and fill factor are not improved.

  This can also be seen from the comparison between Examples 1 and 2 that both the open-circuit voltage and the fill factor are reduced in Example 2 where the n-type conductive silicon oxide layer on is thick. In the embodiment of the present invention, the thickness of the n-type conductive silicon oxide layer 4on is preferably 1 nm to 15 nm, and more preferably 2 nm to 5 nm.

  On the other hand, the n-type amorphous silicon interface layer 4na generates a new electric field between the crystalline i-type silicon photoelectric conversion layer 4ic and the n-type amorphous silicon interface layer 4na to reduce carrier recombination at the interface. The thickness is preferably 2.5 nm or more, and more preferably 4 nm or more. When Examples 1 to 3 and Comparative Example 3 are compared, it can be seen that the open circuit voltage is reduced and the short circuit current is also slightly reduced. The difference in the open circuit voltage is due to the fact that the field effect due to the n-type amorphous silicon interface layer 4na is not obtained.

  In addition, the slight difference in the short-circuit current is because the electric field was improved by the n-type amorphous silicon interface layer in the examples, so that carriers could be efficiently recovered and current loss due to recombination could be reduced. Further, from the comparison between Examples 1, 2 and 3, in Example 3 where the film thickness of the n-type amorphous silicon interface layer 4na is small, the film thickness of the n-type amorphous silicon interface layer 4na is More preferably, it is 4 nm or more. If the film thickness of the n-type amorphous silicon interface layer 4na is thin, the electric field is reduced and the open circuit voltage is reduced.

  An n-type crystalline silicon interface layer 4nc is formed on the n-type amorphous silicon interface layer 4na. The n-type crystalline silicon interface layer 4nc may contain one or more elements of oxygen, carbon, and nitrogen to the extent that the contact resistance with the transparent oxide layer 5 is not increased.

  In FIG. 1, a transparent oxide layer 5 and a back reflective electrode layer 6 are formed on the n-type crystalline silicon interface layer 4nc. ZnO, ITO, or the like is used for the transparent oxide 5, and Ag, Al, or an alloy thereof is preferably used for the back reflective electrode layer 6. In forming the transparent oxide layer 5 and the back reflective electrode layer 6, methods such as sputtering and vapor deposition are preferably used. Although FIG. 1 shows the structure of a hybrid thin film solar cell, the number of photoelectric conversion units 4 is not necessarily two, but a crystalline single structure, a stacked solar cell structure of three or more layers. May be.

  Hereinafter, Examples 1, 2 and 3 as silicon-based thin film solar cells according to the present invention will be described in comparison with Comparative Examples 1 and 2 with reference to FIG.

Example 1
FIG. 1 is a cross-sectional view schematically showing a hybrid thin film solar cell produced in each example and each comparative example.

First, the transparent electrode layer 2 having a fine concavo-convex structure on the surface made of SnO ₂ was formed on one main surface of the translucent substrate 1 made of white glass having a thickness of 1.1 mm by a thermal CVD method.

  Next, in order to form the amorphous photoelectric conversion unit 3, the transparent substrate 1 on which the transparent electrode layer 2 is formed is introduced into a high-frequency plasma CVD apparatus, heated to a predetermined temperature, and then has a thickness of 15 nm. An amorphous p-type silicon carbide layer 3pa, a non-doped amorphous i-type silicon photoelectric conversion layer 3ia having a thickness of 300 nm, and an n-type silicon layer 3nc having a thickness of 30 nm were sequentially stacked.

Further, in order to form the crystalline photoelectric conversion unit 4, a plasma CVD apparatus is used to form a p-type crystalline silicon layer 4pc having a thickness of 15 nm and a crystalline i-type silicon photoelectric conversion layer 4ic having a thickness of 1.5 μm, n An n-type amorphous silicon interface layer 4na having a thickness of 3 nm and a thickness of 5 nm and an n-type microcrystalline silicon interface layer 4nc having a thickness of 7.5 nm were sequentially stacked. The film forming conditions of the n-type conductive silicon oxide layer 4on at that time are as follows: substrate forming surface-electrode distance of 8 to 15 mm, pressure of 5 to 10 Torr, high frequency power density of 0.2 W / cm ² , SiH ₄ / CO ₂ / The PH ₃ / H ₂ flow rate ratio was set to 1/3/5/260, respectively.

Further, the refractive index measured by spectroscopic ellipsometry of the n-type conductive silicon oxide layer deposited on the glass with a thickness of 300 nm under the same film forming conditions as the n-type conductive silicon oxide layer 4on used in this structure is 2 at a wavelength of 600 nm. 0.3, and the conductivity was 4.3 × 10 ⁻⁴ S / cm. 4 further calculates the ratio of the peak intensity of the amorphous silicon in the vicinity of the peak intensity and 480 cm ^-1 in crystalline Si of 520cm around ^-1 when measuring n-type conductivity silicon oxide layer on the glass by Raman scattering spectroscopy. It was 8.

On the other hand, the film forming conditions of the n-type amorphous silicon interface layer 4na are as follows: the distance between the substrate forming surface and the electrode is 10 to 19 mm, the pressure is 30 to 100 Pa, the high frequency power density is 0.011 W / cm ² , and the SiH ₄ / PH ₃ flow rate ratio. 1/2. In addition, the film forming conditions of the n-type microcrystalline silicon interface layer 4nc are as follows: substrate forming surface-electrode distance 10 to 13 mm, pressure 500 to 1000 Pa, high frequency power density 0.011 W / cm ² , SiH ₄ / PH ₃ / H _The ratio of the _two flow rates was 1/4/200. The conductivity of the n-type silicon interface layer deposited on the glass with a thickness of 300 nm under the same film forming conditions was 100 S / cm.

  Thereafter, a transparent oxide layer 5 made of ZnO having a thickness of 80 nm and a back reflective electrode layer 6 made of Ag having a thickness of 250 nm were formed by EB vapor deposition.

Furthermore, in order to leave the transparent electrode layer 2 and separate the amorphous photoelectric conversion unit 3, the crystalline photoelectric conversion unit 4, the transparent oxide layer 5, and the back reflective electrode layer 6 into islands, RIE etching is performed, An island-shaped separation region was formed. Furthermore, a hybrid thin film solar cell was produced by forming a contact region with the transparent electrode layer 2 by infiltrating solder 2 mm outside from the island-shaped separation region. This hybrid thin-film solar cell has an effective area of 1 cm ² , and in Example 1, a total of 36 solar cells described above were produced on one substrate.

The hybrid thin-film solar cell fabricated in Example 1 was irradiated with pseudo-sunlight having a spectral distribution of AM1.5 and an energy density of 100 mW / cm ² under a measurement atmosphere and a temperature of the solar cell of 25 ± 1 ° C. The output characteristics of the thin-film solar cell were measured by measuring the current. Table 1 shows the average performance of the 36 hybrid thin-film solar cells produced in Example 1.

(Example 2)
In Example 2, almost the same process as in Example 1 was performed, but the point that only the film thickness of the n-type conductive silicon oxide layer 4on was changed to 10 nm was different from Example 1. Table 1 shows the average performance of 36 hybrid thin-film solar cells prepared in Example 2.

(Example 3)
In Example 3, almost the same process as in Example 1 was performed, but the point that only the film thickness of the n-type amorphous silicon interface layer 4na was changed to 3 nm was different from Example 1. Table 1 shows the average performance of 36 hybrid thin-film solar cells prepared in Example 3.

(Comparative Example 1)
Comparative Example 1 was different from Example 1 only in the following points. Instead of sequentially laminating the n-type conductive silicon oxide layer 4on, the n-type amorphous silicon interface layer 4na, and the n-type microcrystalline silicon interface layer 4nc, only the n-type microcrystalline silicon interface layer 4nc having a thickness of 15 nm was formed. Table 1 shows the average performance of 36 hybrid thin film solar cells produced in Comparative Example 1.

(Comparative Example 2)
Comparative Example 1 was different from Example 1 only in the following points. Instead of sequentially stacking the n-type conductive silicon oxide layer 4on, the n-type amorphous silicon interface layer 4na, and the n-type microcrystalline silicon interface layer 4nc, the n-type amorphous silicon interface layer 4na having a thickness of 5 nm and the 7.5-nm thickness An n-type microcrystalline silicon interface layer 4nc was formed. Table 1 shows the average performance of 36 hybrid thin film solar cells produced in Comparative Example 2.

(Comparative Example 3)
Comparative Example 1 was different from Example 1 only in the following points. Instead of sequentially stacking the n-type conductive silicon oxide layer 4on, the n-type amorphous silicon interface layer 4na, and the n-type microcrystalline silicon interface layer 4nc, the n-type conductive silicon oxide layer 4on and the thickness 7.5nm An n-type microcrystalline silicon interface layer 4nc was formed. Table 1 shows the average performance of 36 hybrid thin film solar cells produced in Comparative Example 3.

  From comparison between Example 1 and Comparative Example 1, it can be seen that in Example 1, the open-circuit voltage is improved by 3.2% or more compared to Comparative Example 1.

  From the above, according to the present invention, n-type conductive silicon oxide having a refractive index lower than that of the photoelectric conversion layer is formed thinly behind the photoelectric conversion layer, thereby exhibiting a light confinement effect, and high quality n A type amorphous silicon interface layer can be grown. The n-type amorphous silicon interface layer can generate a strong electric field at the interface between the photoelectric conversion layer and the interface layer and can greatly improve the open circuit voltage. As a result, a silicon-based thin film solar cell can be provided with high efficiency and low cost.

1 is a schematic cross-sectional view of a thin film solar cell including an n-type conductive silicon oxide layer / n-type amorphous silicon interface layer / n-type microcrystalline silicon interface layer according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Translucent substrate 2 Transparent conductive film 3 Amorphous silicon photoelectric conversion unit 3pa Amorphous p-type silicon carbide layer 3ia Amorphous i-type silicon photoelectric conversion layer 3nc n-type crystalline silicon layer 4 Crystalline silicon photoelectric conversion unit 4pc p-type crystalline silicon layer 4ic crystalline i-type silicon photoelectric conversion layer 4on n-type conductive silicon oxide layer 4nan n-type amorphous silicon interface layer 4nc n-type crystalline silicon interface layer 5 transparent oxide layer 6 backside reflective electrode layer

Claims (9)

  A silicon-based thin film characterized in that an n-type conductive silicon oxide layer / n-type amorphous silicon interface layer / n-type microcrystalline silicon interface layer are sequentially arranged behind the crystalline photoelectric conversion layer as viewed from the light incident side Solar cell.   2. The silicon-based thin film solar cell according to claim 1, wherein the n-type conductive silicon oxide layer has a refractive index of 2.7 or less at a wavelength of 600 nm.   3. The silicon-based thin film solar cell according to claim 1, wherein the most abundant constituent element excluding silicon in the n-type conductive silicon oxide layer is oxygen.   4. The silicon-based thin film solar cell according to claim 1, wherein the n-type conductive silicon oxide layer includes a crystalline silicon component in the layer. 5.   5. The silicon-based thin film solar cell according to claim 1, wherein the n-type conductive silicon oxide layer has a thickness of 10 nm or less. Characterized in that the thickness before Symbol n-type amorphous silicon interface layer is 2nm or more, silicon-based thin-film solar cell according to any one of claims 1 to 5.   The silicon-based thin film solar cell according to claim 1, wherein at least one amorphous photoelectric conversion unit and one crystalline photoelectric conversion unit are stacked. A method for producing the silicon-based thin film solar cell according to claim 1,
  A method for producing a silicon-based thin-film solar cell, wherein the n-type conductive silicon oxide layer, the n-type amorphous silicon interface layer, and the n-type microcrystalline silicon interface layer are sequentially formed on a crystalline photoelectric conversion layer. The n-type conductive silicon oxide layer is made of SiH. ₄ , H ₂ , CO ₂ , And PH ₃ The method for producing a silicon-based thin film solar cell according to claim 8, wherein the film is formed by a plasma CVD method using as a raw material gas.