JP2012256776A - Manufacturing method of thin-film photoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a thin-film photoelectric conversion device capable of obtaining an excellent photoelectric conversion efficiency.SOLUTION: A manufacturing method of a thin-film photoelectric conversion device which laminates and forms a plurality of photoelectric conversion units including a photoelectric conversion layer which is composed of a semiconductor film and performs photoelectric conversion between a first electrode layer composed of a conductive film and a second electrode layer composed of a transparent conductive film comprises a step of forming a first photoelectric conversion unit of a first electrode layer side among the plural photoelectric conversion units and a step of forming a second photoelectric conversion unit of a second electrode layer side among the plural photoelectric conversion units. The step of forming the first photoelectric conversion unit forms a first concave-convex shape on a surface of the first electrode layer side and forms a second concave-convex shape having a concave-convex level difference smaller than the first concave-convex shape or a short concave-convex pitch on a surface of the second electrode layer side. The step of forming the second photoelectric conversion unit forms a concave-convex shape in which the second concave-convex shape was reflected on the surface of the second electrode layer side and forms a photoelectric conversion layer composed of a material whose absorption wavelength is shorter than a photoelectric conversion layer of the first photoelectric conversion unit.

Description

  The present invention relates to a method for manufacturing a thin film photoelectric conversion device.

  From the viewpoint that the thin film silicon solar cell that is a thin film photoelectric conversion device is less used than the crystalline silicon solar cell that is a bulk photoelectric conversion device, and can be produced at low cost. Research and development are active. As a method of manufacturing a thin film silicon solar cell, a method of forming a thin film photoelectric conversion cell by a plasma CVD method is used, and a form in which an amorphous silicon film or a microcrystalline silicon film is used for a photoelectric conversion layer is generally studied. Yes.

  In a thin-film silicon solar battery cell, a thin-film photoelectric conversion unit that contributes to power generation is configured by stacking a p-type semiconductor layer, an i-type semiconductor layer (photoelectric conversion layer), and an n-type semiconductor layer. Moreover, in order to take out the electric power which generate | occur | produced in the thin film photoelectric conversion unit, a p-type semiconductor layer and an n-type semiconductor layer are each connected to an electrode, and are used as a photoelectric conversion cell including these.

  Since sunlight needs to reach the i-type semiconductor layer (photoelectric conversion layer) in order to generate power, at least one of the electrodes needs to be transparent (light absorption of sunlight) (transparent electrode) layer). With respect to the other electrode, from the viewpoint of returning to the i-type semiconductor layer (photoelectric conversion layer) the transmitted light that has not been absorbed by the i-type semiconductor layer (photoelectric conversion layer) of the incident sunlight, A high electrode (reflection electrode layer) is used.

  In such a thin film silicon solar battery cell, a tandem structure is utilized in order to improve the photoelectric conversion efficiency. The tandem structure is a structure in which a plurality of thin film photoelectric conversion units having different absorption wavelength ranges of a thin film semiconductor layer are stacked as a thin film photoelectric conversion unit formed between a transparent electrode layer and a reflective electrode layer. It is a structure that can be used more effectively.

As an example of a tandem structure, an amorphous silicon layer having a wider band gap is used as the thin film photoelectric conversion layer on the light incident side, and a microcrystal having a narrow band gap is used on the thin film photoelectric conversion layer on the reflection side. A structure using a silicon layer is considered. In the film formation of the microcrystalline silicon, for example, the ratio between the crystalline silicon peak of amorphous silicon peak and 520 cm ^-1 in the 480 cm ^-1 in the Raman scattering spectrum, as shown in Patent Document 1 is defined as the crystallization rate, The characteristics are also affected by the optimization of the crystallization rate. The crystallization rate depends on the film formation process so that the crystallization rate can be lowered by increasing the flow rate of the silane (SiH ₄ ) gas used at the time of film formation or by reducing the RF power. It is possible to change the crystallization rate from about 0.5 to about 10.

  Hereinafter, a general manufacturing method of the thin-film silicon solar battery will be described. For example, a reflective electrode layer having high light reflectivity is formed on a light-transmitting insulating substrate such as glass. When a high light reflective metal substrate is used as the substrate, a transparent conductive layer is formed on the high light reflective metal substrate by a sputtering method or the like.

  Next, an n-type semiconductor layer, an i-type semiconductor layer (photoelectric conversion layer), and a p-type semiconductor layer are sequentially stacked on the reflective electrode layer (transparent conductive layer) using a plasma CVD method or the like to form a thin film photoelectric conversion unit. Form. In the tandem structure, after a thin film photoelectric conversion unit using a microcrystalline silicon layer is formed, a thin film photoelectric conversion unit using an amorphous silicon layer is stacked. Thereafter, a transparent conductive oxide such as zinc oxide (ZnO) or indium tin oxide (ITO) is formed on the thin film photoelectric conversion unit to produce a thin film silicon solar battery cell.

  Moreover, in a tandem-type thin film silicon solar cell, it may have both light transmittance and light reflectivity between laminated thin film photoelectric conversion units, and a conductive intermediate reflection layer may be interposed. When this intermediate reflective layer is provided, light having a wavelength suitable for the light incident side thin film photoelectric conversion unit side out of the light that has passed through the light incident side photoelectric conversion unit can be reflected by the intermediate reflective layer. For this reason, the effect that the effective film thickness of the photoelectric converting layer of the thin film photoelectric conversion unit by the side of light incidence can be increased is acquired.

  As described above, the wavelength of light to be absorbed varies depending on the type of film used in the photoelectric conversion layer, and the amount of light absorbed varies depending on the film thickness. Since the amount of light absorbed by the photoelectric conversion layer increases as the film thickness of the photoelectric conversion layer increases, it is necessary to increase the film thickness of the photoelectric conversion layer in order to improve the performance of the thin film silicon solar cell. preferable. However, increasing the film thickness of the photoelectric conversion layer affects the film quality of the photoelectric conversion layer as well as cost and throughput. For this reason, a technique for absorbing a large amount of light with a thin photoelectric conversion layer is required.

  As such a technique, a texture structure is used. The texture structure is a structure in which irregularities are formed on the surface of the film. The purpose is to reduce reflection at the interface and lengthen the path length of incident light by changing the incident angle of light. It is said. For this reason, the wavelength of the light scattered efficiently changes with the height difference of the unevenness | corrugation in a texture structure, and the pitch of a plane direction. The ratio of the scattered transmittance to the total transmittance is called a haze ratio. In order to absorb a large amount of light in the photoelectric conversion layer, it is preferable that the haze ratio with respect to the wavelength of light absorbed in the photoelectric conversion layer is high.

  Advantages of the texture structure include a reduction in reflectivity as the scattered light increases. For example, Non-Patent Document 1 describes a texture structure suitable for reducing the light reflectance at the time of incidence from a transparent conductive film to a silicon film. When the wavelength is 700 nm or less, the width is 300 nm, the height is 200 nm, and the wavelength is 700 nm. In the above, there is a description that the reflectivity decreases when the width is about 450 nm and the height is about 300 nm. Roughly speaking, it can be said that the unevenness of the texture structure of the transparent conductive film desirably has a width (W) of about half of the target wavelength and a height (H) of about 2/3 thereof. A suitable ratio of height (H) to width (W) is about W = 1.5H. When the unevenness height (H) is high, the photoelectric conversion layer is likely to have defects due to the steep shape of the surface of the transparent conductive film. When the unevenness height (H) is low, the surface of the transparent conductive film is Since it is locally approximated to a flat shape, a result suitable for reflection / scattering characteristics cannot be obtained.

  In the following, the expression of the texture shape (uneven shape) of the texture structure represents an ideal shape that generally satisfies the relationship between the width (W) and the height (H) as described above. Unless otherwise stated, the value of the height portion is described, and the width has a value of about 1.5 times the height as can be seen from the above values. For example, the expression “texture shape of about 300 nm” indicates “texture shape having a height (unevenness level difference) of about 300 nm and a width of about 450 nm”. In the present specification, the height of the texture shape is defined by the difference in height between a valley portion in a texture structure formed in a hemispherical shape or a triangular wave shape and a mountain formed between the valley adjacent to this valley. The width of the texture shape is defined by the distance between adjacent valleys.

  When a microcrystalline thin film is formed on a large texture structure, a shape reflecting the underlying texture structure is also formed on the surface after film formation. Patent Document 2 reports a texture shape conversion method using an intermediate layer inserted between a microcrystalline silicon cell and an amorphous silicon cell. In this method, the roughness of the texture structure can be increased or decreased by processing the formed intermediate layer or the like.

JP 2010-34411 A JP 2009-135537 A

Asahi Glass Co., Ltd., “Research and development of ultra-high light confinement thin-film silicon solar cells”, New Energy and Industrial Technology Development Organization, [online], February 2, 2007 Report on the ex-post evaluation committee of “Next-generation photovoltaic power generation system technology R & D”, [May 17, 2011 search], Internet <http://www.nedo.go.jp/content/100086788.pdf>

  By the way, when the wavelength at which the reflectance is reduced in the texture structure as described above is considered, when considered on the light reflection side, it is reflected from the reflective electrode side with respect to the microcrystalline silicon cell having an absorption wavelength of about 1000 nm. Regarding the incoming light, it can be said that it is preferable to form a texture shape having a width of about 500 nm and a height of about 350 nm on the base. Here, when a microcrystalline silicon cell is formed on an underlying layer having a texture structure, the roughness of the surface of the microcrystalline silicon cell is only slightly reduced from the roughness of the surface of the underlying layer. It can be said that it almost follows the texture structure of the ground layer.

  In a tandem-type thin film silicon solar cell, an amorphous silicon cell is produced on this microcrystalline silicon cell. Considering the incident light side, it can be said that a texture shape having a height of about 200 nm is necessary for an amorphous silicon cell having an absorption wavelength of about 400 nm to 500 nm. Therefore, when an amorphous silicon cell is formed on a microcrystalline silicon cell as it is, a large unevenness is formed on the surface of the amorphous silicon cell compared to an appropriate texture shape for the amorphous silicon cell. The For this reason, it is necessary to reduce the texture shape formed on the surface of the amorphous silicon cell to about 200 nm.

  However, in order to reduce a texture shape of about 350 nm to a texture shape of about 200 nm, an operation on a film having a thickness of at least 150 nm, that is, a device at the time of film formation or processing after film formation is necessary.

  In addition, although the intermediate layer does not contribute to power generation, it absorbs light and functions as a resistance to current. From such a viewpoint, the film thickness is often set to several tens of nm. Therefore, the size of the texture shape that can be controlled using the intermediate layer having this film thickness is about several tens of nm, and the change in size of the texture shape of several hundred nm that was originally formed cannot be absorbed.

  On the other hand, when an intermediate layer having a thickness of several hundred nm is formed in order to absorb the change in size of the texture shape of several hundred nm, in addition to the increase in characteristics of solar cell characteristics such as light absorption, The film thickness of the intermediate layer becomes non-uniform. If the film thickness of the intermediate layer is nonuniform, the junction resistance and reflectance between the photoelectric conversion units become nonuniform, and stable solar cell characteristics cannot be obtained.

  This invention is made | formed in view of the above, Comprising: It aims at obtaining the manufacturing method of the thin film photoelectric conversion apparatus from which favorable photoelectric conversion efficiency is obtained stably.

  In order to solve the above-described problems and achieve the object, a method for manufacturing a thin film photoelectric conversion device according to the present invention includes a first electrode layer made of a conductive film and a second electrode layer made of a transparent conductive film. A method of manufacturing a thin film photoelectric conversion device comprising a plurality of photoelectric conversion units each including a photoelectric conversion layer made of a semiconductor film and performing photoelectric conversion, wherein the first electrode layer side of the plurality of photoelectric conversion units In the step of forming one photoelectric conversion unit, a first uneven shape is formed on the surface on the first electrode layer side, and an uneven step or a short uneven pitch smaller than the first uneven shape is formed on the surface on the second electrode layer side. In the step of forming a second photoelectric conversion unit on the second electrode layer side among the plurality of photoelectric conversion units, the second uneven shape is formed on the surface on the second electrode layer side. Uneven shape reflecting Forming a, to form the photoelectric conversion layer absorbs the wavelength of light is a short material than the photoelectric conversion layer of the first photoelectric conversion unit, and wherein.

  According to the present invention, there is an effect that it is possible to obtain a method for manufacturing a thin film photoelectric conversion device in which good photoelectric conversion efficiency is stably obtained.

FIG. 1 is a cross-sectional view schematically showing the configuration of the thin-film solar battery according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of a method for forming a texture structure on the surface of the transparent electrode layer. FIG. 3 is a cross-sectional view schematically showing another example of the method for forming the texture structure on the surface of the transparent electrode layer. FIGS. 4-1 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. FIGS. FIGS. 4-2 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. FIGS. FIGS. 4-3 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. FIGS. 4-4 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. 4-5 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. 4-6 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. 4-7 is sectional drawing for demonstrating the manufacturing method of the thin film photovoltaic cell concerning Embodiment 1 of this invention. FIGS. 5-1 is sectional drawing which shows typically the additional processing method with respect to the texture structure concerning Embodiment 4 of this invention. FIGS. 5-2 is sectional drawing which shows typically the additional processing method with respect to the texture structure concerning Embodiment 4 of this invention. FIG. 6: is sectional drawing which shows typically the structure of the thin film photovoltaic cell produced by applying the formation method of the texture structure concerning Embodiment 5 of this invention.

  Embodiments of a method for manufacturing a thin film photoelectric conversion device according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view schematically showing a configuration of a thin film solar battery cell (hereinafter referred to as a cell) 201 which is a thin film photoelectric conversion device according to a first embodiment of the present invention. As shown in FIG. 1, in the cell 201 according to the first embodiment, a reflective electrode layer 101 is formed on an insulating substrate 100.

  As the insulating substrate 100, for example, a glass substrate is used as the insulating substrate. However, the insulating substrate 100 is not necessarily made of glass, and a substrate made of resin or the like can also be used.

  The reflective electrode layer 101 functions as a back electrode and also functions as a reflective layer that reflects light that has not been absorbed by the photoelectric conversion unit and returns the light to the photoelectric conversion unit again, thereby contributing to improvement in photoelectric conversion efficiency. Therefore, the reflective electrode layer 101 is required to have conductivity and light reflectivity, and the higher the conductivity and the higher the light reflectivity, the better. The reflective electrode layer 101 includes, for example, a metal material such as silver (Ag), aluminum (Al), titanium (Ti), or palladium having a high visible light reflectivity, or an alloy of these metal materials, a nitride of these metal materials, These metal materials can be used to form oxides. The characteristics required for the reflective electrode layer 101 are a low electrical resistance and a high reflectance, and are not particularly defined as long as this condition is satisfied. The reflective electrode layer 101 may have a stacked structure of a plurality of electrode layers. Furthermore, the insulating substrate 100 is not necessarily required if a reflective electrode can be used as the substrate.

A transparent electrode layer 102 is formed on the reflective electrode layer 101. The transparent electrode layer 102 is made of a transparent conductive film having translucency. The transparent electrode layer 102 is, for example, a transparent conductive material containing at least one of zinc oxide (ZnO), indium tin oxide (ITO), tin oxide (SnO ₂ ), and indium oxide (In ₂ O ₃ ). It is composed of an oxide film (TCO: Transparent Conducting Oxide) or a transparent conductive film in which these are laminated. In addition, the transparent electrode layer 102 is formed by using aluminum (Al), gallium (Ga), indium (In), boron (B), yttrium (Y), silicon (Si), zirconium (Zr), You may be comprised by the translucent film | membrane using at least 1 or more types of element selected from titanium (Ti) and fluorine (F). Such a transparent electrode layer 102 is formed using methods, such as CVD method, sputtering method, a vapor deposition method, for example.

  The transparent electrode layer 102 has a texture structure 102S having fine irregularities on the surface. The texture structure 102S has a function of scattering light reflected by the reflective electrode layer 101, absorbing light more efficiently by the first photoelectric conversion unit 103, and improving light use efficiency. The texture structure 102S is a structure suitable for light absorption in the microcrystalline silicon photoelectric conversion layer 103b in which the light absorption wavelength described later is about 1000 nm. The formation method of a surface texture structure is not specifically limited, A well-known method can be used.

  The transparent electrode layer 102 is formed for the purpose of preventing deterioration due to contact between the reflective electrode layer 101 and the first photoelectric conversion unit 103 described later, and thus the reflective electrode layer 101 and the first photoelectric conversion unit 103 react with each other. If not, it is not always necessary. When the transparent electrode layer 102 is omitted, the texture structure 102S described above is formed on the surface of the reflective electrode layer 101.

  Since this texture structure 102S needs to be finally formed on the surface portion of the transparent electrode layer 102 on the first photoelectric conversion unit 103 side, the insulating substrate 100, the reflective electrode layer 101, or the transparent electrode layer 102 is required. Of these, the texture structure formed on the surface of at least one layer is the texture structure 102S on the surface of the transparent electrode layer 102.

  Since the transparent electrode layer 102 absorbs light, the film thickness of the transparent electrode layer 102 is preferably as thin as possible, and is preferably 100 nm or less, for example. Therefore, the transparent electrode layer 102 itself is not subjected to processing for forming a texture structure, but a texture structure is formed on the lower insulating substrate 100 or the reflective electrode layer 101, and the shape is formed on the transparent electrode layer 102. It is preferable to reflect and maintain.

  FIG. 2 is a cross-sectional view schematically showing an example of a method for forming a texture structure on the surface of the transparent electrode layer 102. FIG. 2 shows a case where a texture structure is formed on the surface of the insulating substrate 100 and the shape of the texture structure is reflected and maintained on the reflective electrode layer 101 and the transparent electrode layer 102 which are the upper layers. FIG. 3 is a cross-sectional view schematically showing another example of a method for forming a texture structure on the surface of the transparent electrode layer 102. FIG. 3 shows a case where a texture structure is formed on the surface of the reflective electrode layer 101, and the shape of the texture structure is reflected and maintained on the transparent electrode layer 102 as an upper layer.

  A first photoelectric conversion unit 103 is formed on the transparent electrode layer 102. The first photoelectric conversion unit 103 has a pn junction or a pin junction, and is configured by stacking one or more thin film semiconductor layers that generate power by incident light. The first photoelectric conversion unit 103 has a structure in which an n-type silicon semiconductor layer 103a, a microcrystalline silicon photoelectric conversion layer 103b, and a p-type silicon semiconductor layer 103c are stacked from the transparent electrode layer 102 side. It can be formed using a method. On the surface of the microcrystalline silicon photoelectric conversion layer 103b on the p-type silicon semiconductor layer 103c side, a texture structure 103bS ′ having a texture shape of about 150 nm to 200 nm having an average unevenness step smaller than that of the texture structure 103bS is formed.

  On the first photoelectric conversion unit 103, an intermediate reflection layer 104 and a second photoelectric conversion unit 105 are sequentially stacked. The second photoelectric conversion unit 105 has a pn junction or a pin junction, and is configured by laminating one or more thin film semiconductor layers that generate power with incident light. The second photoelectric conversion unit 105 has a structure in which an n-type silicon semiconductor layer 105a, an amorphous silicon photoelectric conversion layer 105b, and a p-type silicon semiconductor layer 105c are stacked from the intermediate reflection layer 104 side. It can be formed using a CVD method.

  Here, the microcrystalline silicon photoelectric conversion layer 103b is used as the photoelectric conversion layer in the first photoelectric conversion unit 103, but the photoelectric conversion layer in the first photoelectric conversion unit 103 is formed of a microcrystalline silicon-based semiconductor material. In addition to intrinsic silicon, alloys such as silicon germanium (SiGe) and silicon carbide (SiC) are also used as the material.

  Further, the amorphous silicon photoelectric conversion layer 105b is used as the photoelectric conversion layer in the second photoelectric conversion unit 105, but the photoelectric conversion layer in the second photoelectric conversion unit 105 is formed of an amorphous silicon-based semiconductor material. In addition to intrinsic silicon, alloys such as silicon germanium (SiGe) and silicon carbide (SiC) are also used as the material.

  Further, the photoelectric conversion layer (microcrystalline silicon photoelectric conversion layer 103b) in the first photoelectric conversion unit 103 and the photoelectric conversion layer (amorphous silicon photoelectric conversion layer 105b) in the second photoelectric conversion unit 105 absorb light that is absorbed. The wavelength range is different. For example, the microcrystalline silicon photoelectric conversion layer 103b as described above absorbs light with a wavelength of about 1100 nm or less, and the amorphous silicon photoelectric conversion layer 105b absorbs light with a wavelength of about 600 nm or less. Thus, by laminating a plurality of photoelectric conversion units having different wavelength ranges of light to be absorbed, light in a wide wavelength range can be effectively utilized.

For the intermediate reflective layer 104 used in such a tandem structure, for example, a transparent conductive oxide film such as tin oxide (SnO ₂ ), titanium oxide (TiO ₂ ), or silicon oxide (SiO ₂ ) can be used. As a characteristic required for the intermediate reflection layer 104, it is necessary to have conductivity so as not to prevent electrical connection between the first photoelectric conversion unit 103 and the second photoelectric conversion unit 105. The intermediate reflection layer 104 preferably reflects light having a wavelength absorbed by the amorphous silicon photoelectric conversion layer 105b and transmits light having a wavelength absorbed by the microcrystalline silicon photoelectric conversion layer 103b. Since the intermediate reflective layer 104 has such characteristics, the amorphous silicon photoelectric conversion layer 105b can sufficiently absorb light even when the film thickness is small.

  Furthermore, the film thicknesses of the respective photoelectric conversion layers (microcrystalline silicon photoelectric conversion layer 103b and amorphous silicon photoelectric conversion layer 105b) of the first photoelectric conversion unit 103 and the second photoelectric conversion unit 105 and the intermediate reflection layer 104 are set as follows. It is important to balance the current generated in each photoelectric conversion unit by changing the current.

  A surface transparent electrode layer 106 is formed on the second photoelectric conversion unit 105. The surface transparent electrode layer 106 is required to have good conductivity and light transmittance, and a film similar to the transparent electrode layer 102 is often used. In the case where a thick film thickness is necessary to give the surface transparent electrode layer 106 high conductivity, for example, a comb-shaped metal electrode layer can be formed on the surface transparent electrode layer 106 for extracting current. It is.

  The cell 201 according to the first embodiment is configured by the laminated structure from the reflective electrode layer 101 to the surface transparent electrode layer 106 or the comb electrode layer as described above.

  Next, a manufacturing method of the cell 201 according to the present embodiment configured as described above will be described with reference to FIGS. 4-1 to 4-7 are cross-sectional views for explaining the method for manufacturing the cell 201 according to the first embodiment.

  First, for example, a glass substrate is prepared as the insulating substrate 100. Then, the reflective electrode layer 101 is formed on one surface side of the insulating substrate 100 by a known method. For example, the reflective electrode layer 101 made of a silver (Ag) film having a high reflectance is formed by a sputtering method.

  Next, the transparent electrode layer 102 with high conductivity is formed on the reflective electrode layer 101 by a known method (FIG. 4A). For example, the transparent electrode layer 102 made of a zinc oxide (ZnO) film is formed on the reflective electrode layer 101 by a sputtering method. Further, as a film formation method, another film formation method such as a CVD method may be used.

  At this point, the texture structure 102S is formed on the surface of the transparent electrode layer 102. The texture structure 102S formed on the surface of the transparent electrode layer 102 is a structure suitable for light absorption in the microcrystalline silicon photoelectric conversion layer 103b having a light absorption wavelength of about 1000 nm. Therefore, as a texture structure suitable for reducing the reflectance of light having such a wavelength when entering the silicon film from the transparent electrode layer 102, the width is about 500 nm, and the height (unevenness step) is about 350 nm. A texture structure 102S having a shape is formed. That is, the texture structure 102S is formed on the surface of the transparent electrode layer 102 which is an adjacent layer in contact with the n-type silicon semiconductor layer 103a on the reflective electrode layer 101 side.

  As a method of forming the texture structure 102S, there is a method of forming a texture structure on the insulating substrate 100 or the reflective electrode layer 101. For example, a method in which a resist pattern is formed on the insulating substrate 100 or the reflective electrode layer 101 and then wet etching or dry etching is performed, or the surface of the insulating substrate 100 or the surface of the reflective electrode layer 101 is directly applied to the surface by a laser or the like. Examples thereof include a method of forming a concavo-convex pattern.

  Further, as a method of forming the texture structure 102S, a method of removing the fine particles by forming the reflective electrode layer 101 after the fine particles are dispersed on the insulating substrate 100, and a film forming condition and a film thickness of the reflective electrode layer 101 are appropriately set. It is also possible to adopt a method of forming irregularities on the surface by setting to. After the texture structure is formed on the insulating substrate 100 or the reflective electrode layer 101 by these methods, the reflective electrode layer 101 and the transparent electrode layer 102 are formed on these upper layers, or the transparent electrode layer 102 is formed. The texture structure 102S reflecting and maintaining the shape of the texture structure of the lower layer can be formed on the transparent electrode layer 102.

  Further, as a method of directly processing and forming the texture structure 102S on the transparent electrode layer 102, a method of etching the surface of the transparent electrode layer 102 made of a zinc oxide (ZnO) film or the like formed by a sputtering method with an acid, or the like. Is mentioned.

  Next, an n-type silicon semiconductor layer 103a having a thickness of about 100 nm or less is formed on the transparent electrode layer 102 having the texture structure 102S by a known method (FIG. 4-2). For example, the n-type silicon semiconductor layer 103a is formed on the transparent electrode layer 102 by plasma CVD. A texture structure 103aS similar to the texture structure 102S reflecting and maintaining the shape of the underlying texture structure is formed on the surface of the n-type silicon semiconductor layer 103a.

  Next, a microcrystalline silicon photoelectric conversion layer 103b having a thickness of about 1500 nm is formed on the n-type silicon semiconductor layer 103a having the texture structure 103aS by a known method (FIG. 4-3). For example, the microcrystalline silicon photoelectric conversion layer 103b is formed on the n-type silicon semiconductor layer 103a by plasma CVD. A texture structure 103bS similar to the texture structure 102S (texture structure 103aS) is formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b. Here, the film thickness of the microcrystalline silicon photoelectric conversion layer 103b is preferably about 400 nm to 5000 nm.

Next, the texture structure 103bS on the surface of the microcrystalline silicon photoelectric conversion layer 103b is subjected to additional processing for changing the texture shape and relaxing the texture shape. As an additional process for the texture structure 103bS, for example, silicon fine particles 301 having a diameter of about 500 nm to 2000 nm are dispersed on the microcrystalline silicon photoelectric conversion layer 103b, and then dry etching is performed on the surface of the microcrystalline silicon photoelectric conversion layer 103b. Implement (Figure 4-4). As the etching conditions, for example, a mixed gas of CF ₄ and O ₂ is used as an etching gas, and the gas flow rates are CF ₄ : 100 sccm, O ₂ : 10 sccm, pressure: 1.3 Pa, and RF: 300 W. Under such conditions, the texture structure 103bS on the surface of the microcrystalline silicon photoelectric conversion layer 103b is etched by 150 nm in the height direction so that the convex portions of the texture structure 103bS not covered with the silicon fine particles 301 are formed. By selectively etching, the surface of the texture structure 103bS is formed with unevenness having a height (unevenness step) of about 150 nm to 200 nm on the silicon surface.

As an etching gas at this time, it is also possible to use a single gas containing CHF ₃ , C ₄ F ₈ , CF ₄ , SF ₆ and an etching gas mixed with O ₂ , He, Ar, or the like. Further, the material of the silicon fine particles 301 is not limited to silicon, and alumina or the like may be used. When this method is used, the applied silicon fine particles 301 can be removed by washing with a brush.

  By performing such processing, a texture having a structure in which high protrusions in the texture structure 103bS are processed and unevenness having a height (unevenness step) of about 150 nm to 200 nm is added to the original texture structure 103bS. The structure 103bS ′ can be obtained (FIGS. 4-5). The texture structure 103bS 'has a texture shape of about 150 nm to 200 nm, and the average unevenness level is smaller than that of the texture structure 103bS.

  In the additional processing as described above, since the microcrystalline silicon photoelectric conversion layer 103b is formed thick and has a film thickness sufficient to change the texture structure of the surface, a process including processing after film formation is performed. It becomes easy. Further, since the texture shape is changed with respect to the thick microcrystalline silicon photoelectric conversion layer 103b, the variation in characteristics due to the film thickness is small, and the influence on current matching in the tandem structure is reduced.

  Next, a p-type silicon semiconductor layer 103c having a thickness of about 15 nm is formed on the microcrystalline silicon photoelectric conversion layer 103b having the texture structure 103bS ′ by a known method. For example, the p-type silicon semiconductor layer 103c is formed on the microcrystalline silicon photoelectric conversion layer 103b by plasma CVD. The surface of the p-type silicon semiconductor layer 103c reflects and maintains the texture shape of the lower layer, and has the same shape as the texture structure 103bS '.

  Next, the intermediate reflection layer 104, the n-type silicon semiconductor layer 105a, the amorphous silicon photoelectric conversion layer 105b, and the p-type silicon semiconductor layer 105c are formed on the p-type silicon semiconductor layer 103c by a known method (FIG. 4-6). ). For example, these are sequentially formed by plasma CVD.

  Here, the thickness of the intermediate reflection layer 104 is about 10 nm to 100 nm, the thickness of the n-type silicon semiconductor layer 105a is about 10 nm to 100 nm, the thickness of the amorphous silicon photoelectric conversion layer 105b is about 100 nm to 500 nm, and p-type. The film thickness of the silicon semiconductor layer 105c is about 2 nm to 30 nm. The surfaces of these layers reflect and maintain the texture shape of the lower layer, and have the same shape as the texture structure 103bS '. Accordingly, a texture shape of about 150 nm to 200 nm is formed on the surface of the p-type silicon semiconductor layer 105c as a texture structure suitable for light absorption in the amorphous silicon photoelectric conversion layer 105b having a light absorption wavelength of about 400 nm to 500 nm. Is formed.

  Next, the surface transparent electrode layer 106 is formed on the p-type silicon semiconductor layer 105c by a known method (FIGS. 4-7). For example, the surface transparent electrode layer 106 made of a zinc oxide (ZnO) film is formed on the p-type silicon semiconductor layer 105c by plasma CVD. Thus, the cell 201 as shown in FIG. 1 is obtained.

  According to Embodiment 1 described above, a microcrystalline silicon photoelectric conversion layer having an absorption wavelength of light of about 1000 nm is formed on the surface of the transparent electrode layer 102 that is an interface between the transparent electrode layer 102 and the first photoelectric conversion unit 103. As a texture structure suitable for light absorption in 103b, a texture shape of about 350 nm can be formed. Further, on the surface of the p-type silicon semiconductor layer 105c which is an interface between the surface transparent electrode layer 106 and the second photoelectric conversion unit 105, an amorphous silicon photoelectric conversion layer 105b whose light absorption wavelength is about 400 nm to 500 nm is provided. As a texture structure suitable for light absorption, a texture shape of about 150 nm to 200 nm can be formed.

  As a result, reflection of reflected light at the reflective electrode layer 101 can be reduced at the interface between the transparent electrode layer 102 and the first photoelectric conversion unit 103, and an optical path length in the first photoelectric conversion unit 103 can be increased due to diffuse reflection. The power generation efficiency of the cell 201 can be improved. Further, it is possible to achieve a reduction in reflection of incident light at the interface between the surface transparent electrode layer 106 and the second photoelectric conversion unit 105 and an increase in the optical path length in the second photoelectric conversion unit 105 due to diffuse reflection. Can be improved.

  Furthermore, the intermediate reflective layer 104 may be formed with a thin and uniform thickness, and variations in solar cell characteristics due to light absorption loss and non-uniformity of the film can be suppressed. Moreover, it becomes possible to easily balance the generated currents of the first photoelectric conversion unit 103 and the second photoelectric conversion unit 105, and stable photoelectric conversion efficiency can be obtained. Note that the intermediate reflective layer 104 can be omitted if not necessary, and in that case, absorption of light by the intermediate reflective layer 104 can also be suppressed.

  Therefore, according to Embodiment 1, the thin film photovoltaic cell from which favorable photoelectric conversion efficiency is obtained stably is realizable.

Embodiment 2. FIG.
In Embodiment 2, another embodiment of an additional processing method for the texture structure 103bS on the surface of the microcrystalline silicon photoelectric conversion layer 103b will be described. As an additional processing method in Embodiment 2, after a pattern made of an organic material such as a resist is formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b by a printing technique, the surface of the microcrystalline silicon photoelectric conversion layer 103b is wet. Etching is performed. Here, the pattern made of an organic material has a texture shape of about 350 nm (texture structure 103bS) formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b by wet etching using the pattern as a mask to a texture of about 150 nm to 200 nm. It is formed with a pattern that can be processed into a shape (texture structure 103bS ′).

  Examples of the etching method include a method in which an alkaline solution such as a potassium hydroxide aqueous solution of about 0.3 wt% is sprayed on the surface of the microcrystalline silicon photoelectric conversion layer 103b. By this method, a portion of the texture structure 103bS that is not covered with a pattern made of an organic material is selectively etched, and the texture structure 103bS can be processed. Further, as the etching solution, TMAH (tetramethylammonium hydroxide), ethylenediamine pyrocatechol, hydrated hydrazine, or the like may be used.

  After the additional processing is performed, the pattern made of an organic material is removed with acetone or the like, so that the texture structure 103bS ′ (see FIG. 4-5) as described in Embodiment 1 becomes the surface of the microcrystalline silicon photoelectric conversion layer 103b. Formed.

  By using this method, other members provided on the surface of the microcrystalline silicon photoelectric conversion layer 103b for additional processing can be completely removed, and other members can be removed on the surface of the microcrystalline silicon photoelectric conversion layer 103b after the additional processing. Since the member can be prevented from remaining, a clean processed surface can be obtained. Then, the cells 201 can be manufactured in the same manner as in Embodiment 1 except for the additional processing for the texture structure 103bS.

  In addition, it is also possible to perform additional processing by a physical removal method such as blasting or ion milling instead of wet etching.

  Therefore, according to the second embodiment, it is possible to realize a thin-film solar battery in which good photoelectric conversion efficiency can be stably obtained as in the first embodiment.

Embodiment 3 FIG.
In Embodiment 3, another embodiment of an additional processing method for the texture structure 103bS on the surface of the microcrystalline silicon photoelectric conversion layer 103b will be described. In the additional processing method in Embodiment 3, crystal grain boundaries that exist in large numbers on the surface of the microcrystalline silicon photoelectric conversion layer 103b are used. That is, after forming the microcrystalline silicon photoelectric conversion layer 103b, the surface is exposed to oxygen, so that a silicon oxide film is formed on the outermost surface portion and the grain boundary portion. At this time, oxygen penetrates deeper into the grain boundary than in the region other than the grain boundary.

  Thereafter, wet etching with hydrofluoric acid or dry etching with fluorine-based plasma can be performed to selectively etch the outermost surface portion and grain boundary portion of the oxidized microcrystalline silicon photoelectric conversion layer 103b. Can be formed. As a result, the texture structure 103bS ′ (see FIG. 4-5) as described in the first embodiment is formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b. Then, the cells 201 can be manufactured in the same manner as in Embodiment 1 except for the additional processing for the texture structure 103bS.

  When this method is used, there is an advantage that a patterning material as in the first and second embodiments is not necessary.

  Therefore, according to the third embodiment, a thin-film solar battery that can stably obtain good photoelectric conversion efficiency as in the first embodiment can be realized.

Embodiment 4 FIG.
In Embodiment 4, another embodiment of an additional processing method for the texture structure 103bS on the surface of the microcrystalline silicon photoelectric conversion layer 103b will be described with reference to FIGS. FIGS. 5A and 5B are cross-sectional views schematically illustrating an additional processing method for the texture structure 103bS according to the fourth embodiment.

  In the additional processing method in Embodiment 4, after forming the microcrystalline silicon photoelectric conversion layer 103b once, the process of planarizing the surface of this microcrystalline silicon photoelectric conversion layer 103b is implemented (FIG. 5-1). Examples of a method for planarizing the surface of the microcrystalline silicon photoelectric conversion layer 103b include mechanical polishing and CMP (Chemical Mechanical Polishing). Note that in the planarization of the surface of the microcrystalline silicon photoelectric conversion layer 103b, as long as a large uneven step can be removed, a small uneven portion having the same level or less as the texture structure 103bS 'may remain.

  After planarizing the surface of the microcrystalline silicon photoelectric conversion layer 103b, the microcrystalline silicon photoelectric conversion layer 103b is formed again, and an additional processing step as shown in Embodiment Modes 1 to 3 is performed. Thus, the texture structure 103bS ′ as described in the first embodiment is formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b (FIG. 5-2). Then, the cells 201 can be manufactured in the same manner as in Embodiment 1 except for the additional processing for the texture structure 103bS.

  By once planarizing the surface of the microcrystalline silicon photoelectric conversion layer 103b, defects in the microcrystalline silicon photoelectric conversion layer 103b caused by the original texture structure (texture structure 103bS) can be easily eliminated. For this reason, it is preferable to carry out the planarization step as much as possible so as to remove the height (unevenness level difference) of the original texture (350 nm in this embodiment) (FIG. 5-1).

  For example, after the microcrystalline silicon photoelectric conversion layer 103b having a thickness of about 500 nm is formed over the n-type silicon semiconductor layer 103a, a planarization process is performed. Accordingly, the microcrystalline silicon photoelectric conversion layer 103b with few defects formed after planarization can be formed thick. Note that a sufficient microcrystalline silicon photoelectric conversion layer 103b may be formed first, and the formation of the microcrystalline silicon photoelectric conversion layer 103b again may be omitted.

  Therefore, according to the fourth embodiment, it is possible to realize a thin-film solar battery in which good photoelectric conversion efficiency can be stably obtained as in the first embodiment.

Embodiment 5 FIG.
In the fifth embodiment, another embodiment of a method for forming the texture structure 103bS will be described. First, through the manufacturing steps similar to those of the first embodiment, the layers up to the n-type silicon semiconductor layer 103a of the first photoelectric conversion unit 103 are formed. Thereafter, the microcrystalline silicon photoelectric conversion layer 103b is formed. By changing the film formation condition during the film formation of the microcrystalline silicon photoelectric conversion layer 103b, the microcrystalline silicon photoelectric conversion layer 103b is changed. The texture shape formed on the surface of the layer 103b can be changed. In the microcrystalline silicon film, film formation proceeds so as to relax the texture shape when the crystallized state is low, and fine irregularities due to crystal grains are formed on the surface when the crystallized state is highly crystallized.

When a microcrystalline silicon film is formed by a CVD process, the crystallization rate is set to 0.3 by setting the silane (SiH ₄ ) gas flow rate at the initial stage of film formation to about 1.5 times the original film formation conditions. It is possible to suppress to about twice. By forming a silicon layer having a low crystallization rate (close to amorphous) in the initial stage by such a method, the surface of the silicon film can be smoothed.

Then, as the film formation proceeds, the silane (SiH ₄ ) gas flow rate is reduced, and the film formation under the original film formation conditions proceeds to form a silicon layer with a high crystallization rate. However, when the layer having a low crystallization rate is increased to a thickness of 100 nm or more, the series resistance component is significantly increased. For this reason, the thickness of the portion (initial layer) where the crystallization rate is lowered is preferably 100 nm or less. In this case, regarding the height of the texture shape (uneven steps) formed on the surface of the microcrystalline silicon photoelectric conversion layer 103b, from the same height (uneven steps) as the texture structure 102S (texture structure 103aS), 20 nm to 25 nm. The degree is alleviated.

  Then, the texture shape of the surface of the silicon film formed by subsequent film formation under the original film formation conditions reflects and maintains the texture shape of the lower layer of the silicon layer with a low crystallization rate (close to amorphous). Is done. From this, in order to reduce the height of the texture shape (concave step) on the surface of the microcrystalline silicon photoelectric conversion layer 103b from about 350 nm reflecting the texture structure 102S (texture structure 103aS) to about 150 nm, The formation of a silicon layer having a low conversion rate (close to amorphous) is repeated about 8 to 10 times.

Microcrystalline silicon photoelectric conversion is performed by repeating alternate film formation with silicon layers with high crystallization rate, even in silicon layers with low crystallization rate (close to amorphous). An increase in the series resistance component of the layer 103b is suppressed. After forming a silicon layer with a desired film thickness, a silicon layer having a crystallization rate about twice as high is finally obtained by setting the silane (SiH ₄ ) gas flow rate to about 0.7 times the original film forming conditions. By forming the silicon layer, a texture structure having fine irregularities having an average irregularity pitch shorter than that of the texture structure 103bS can be formed on the surface. By the above process, the microcrystalline silicon photoelectric conversion layer 103b having the texture structure 103bS ′ as described in the first embodiment formed on the surface is obtained.

  By using this method, processing after the microcrystalline silicon photoelectric conversion layer 103b is formed becomes unnecessary, so that it is possible to suppress the entry of impurities into the silicon film, and the p-type silicon semiconductor is continuously provided. The layer 103c can be formed.

  FIG. 6 is a cross-sectional view schematically showing a configuration of a thin-film solar battery manufactured by applying the texture structure forming method according to the fifth embodiment. The cell shown in FIG. 6 has a configuration in which the third photoelectric conversion unit 107 is inserted between the second photoelectric conversion unit 105 and the surface transparent conductive layer 106 based on the configuration of the cell 201. The third photoelectric conversion unit 107 has a structure in which an n-type silicon semiconductor layer 107a, a silicon carbide photoelectric conversion layer 107b, and a p-type silicon semiconductor layer 107c are stacked from the second photoelectric conversion unit 105 side. It can be formed using a method.

  In this cell, the photoelectric conversion layer of the first photoelectric conversion unit 103 is a microcrystalline silicon germanium photoelectric conversion layer 103 b ′ using microcrystalline silicon germanium that absorbs light having a longer wavelength than microcrystalline silicon. The microcrystalline silicon germanium photoelectric conversion layer 103b ′ includes a silicon germanium initial layer 103b1 having a low crystallization rate, a microcrystalline silicon germanium layer 103b2 having a high crystallization rate, and a microcrystalline silicon germanium layer 103b2 formed by the above-described method. In addition, a microcrystalline silicon germanium layer 103b3 having a higher crystallization rate is stacked.

  In addition, the photoelectric conversion layer of the third photoelectric conversion unit 107 is a silicon carbide photoelectric conversion layer 107b using silicon carbide that absorbs light having a shorter wavelength than that of amorphous silicon. Accordingly, amorphous silicon germanium or nanocrystalline silicon that can effectively absorb light having a wavelength of about 800 nm can be used for the photoelectric conversion layer of the second photoelectric conversion unit 105, and sunlight is effectively absorbed. can do.

  When such a structure is used, a texture shape having a height (unevenness level) of about 250 nm is appropriate for the second photoelectric conversion unit 105, and a texture of about 100 nm to 150 nm is used for the third photoelectric conversion unit 107. The shape becomes appropriate, and the effect of reducing the number of formations of the initial layer in the control of the texture shape using the film forming method described above can be obtained.

  Therefore, according to the fifth embodiment, a thin-film solar cell that can stably obtain good photoelectric conversion efficiency can be realized as in the first embodiment.

  In addition, by forming a plurality of thin film solar cells having the configuration described in the above embodiment on the insulating substrate 100 and electrically connecting adjacent thin film solar cells, good photoelectric conversion efficiency is stable. A thin film solar cell module obtained in this way can be realized. In this case, what is necessary is just to electrically connect one reflective electrode layer 101 and the other surface transparent electrode layer 106 of an adjacent thin film photovoltaic cell.

  As described above, the method for manufacturing a thin film photoelectric conversion device according to the present invention is useful for manufacturing a thin film photoelectric conversion device that can stably obtain good photoelectric conversion efficiency.

DESCRIPTION OF SYMBOLS 100 Insulating substrate 101 Reflective electrode layer 102 Transparent electrode layer 102S Texture structure 103 1st photoelectric conversion unit 103a N-type silicon semiconductor layer 103aS Texture structure 103b Microcrystalline silicon photoelectric conversion layer 103b 'Microcrystalline silicon germanium photoelectric conversion layer 103b1 Low silicon germanium initial layer 103b2 Highly crystallized microcrystalline silicon germanium layer 103b3 Highly crystallized microcrystalline silicon germanium layer 103bS Texture structure 103c P-type silicon semiconductor layer 104 Intermediate reflective layer 105 Second photoelectric conversion 105a n-type Silicon semiconductor layer 105b Amorphous silicon photoelectric conversion layer 105c P-type silicon semiconductor layer 106 Surface transparent electrode layer 107 Third photoelectric conversion unit 107a N-type silicon semiconductor layer 107 Silicon carbide photoelectric conversion layer 107c p-type silicon semiconductor layer 201 thin film solar cells (cells)
301 Silicon fine particles

Claims (8)

A thin film photoelectric conversion device in which a plurality of photoelectric conversion units each including a photoelectric conversion layer made of a semiconductor film and performing photoelectric conversion are stacked between a first electrode layer made of a conductive film and a second electrode layer made of a transparent conductive film. A manufacturing method of
In the step of forming the first photoelectric conversion unit on the first electrode layer side among the plurality of photoelectric conversion units, a first concavo-convex shape is formed on the surface on the first electrode layer side, and the second electrode layer side is formed. Forming a second concavo-convex shape having a concavo-convex step smaller than the first concavo-convex shape or a short concavo-convex pitch on the surface;
In the step of forming the second photoelectric conversion unit on the second electrode layer side among the plurality of photoelectric conversion units, an uneven shape reflecting the second uneven shape on the surface on the second electrode layer side is formed, Forming the photoelectric conversion layer made of a material having a light absorption wavelength shorter than the photoelectric conversion layer of the first photoelectric conversion unit;
A method of manufacturing a thin film photoelectric conversion device characterized by the above. The photoelectric conversion unit is formed by sequentially laminating a first conductivity type semiconductor layer, the photoelectric conversion layer, and a second conductivity type semiconductor layer from the first electrode layer side.
A first step of forming the first concavo-convex shape on a surface of an adjacent layer in contact with the first photoelectric conversion unit on the first electrode layer side;
The first conductive semiconductor layer of the first photoelectric conversion unit and the photoelectric conversion layer are stacked on the adjacent layer, and have a concavo-convex shape reflecting the concavo-convex shape of the first concavo-convex shape on the surface. A second step of forming the photoelectric conversion layer having a film thickness thicker than the first uneven shape uneven step;
A third step of relaxing the first uneven shape on the surface of the photoelectric conversion layer to form the second uneven shape;
A fourth step of forming the second conductive semiconductor layer of the first photoelectric conversion unit on the photoelectric conversion layer on which the second uneven shape is formed;
A fifth step of stacking and forming one or more photoelectric conversion units on the second conductive semiconductor layer of the first photoelectric conversion unit with the second photoelectric conversion unit as the outermost layer;
A sixth step of forming the second electrode layer on the second photoelectric conversion unit;
The method for producing a thin film photoelectric conversion device according to claim 1, wherein: In the third step,
A step of dispersing and arranging particles on the photoelectric conversion layer;
Etching the surface of the photoelectric conversion layer using the particles as a mask to relax the first uneven shape of the surface of the photoelectric conversion layer and forming the second uneven shape;
Removing the particles;
The manufacturing method of the thin film photoelectric conversion apparatus of Claim 2 characterized by the above-mentioned. In the third step,
Forming a pattern of an organic material on the photoelectric conversion layer;
Etching the surface of the photoelectric conversion layer using the pattern of the organic material as a mask to relax the first uneven shape of the surface of the photoelectric conversion layer and forming the second uneven shape;
Removing the pattern of organic material;
The manufacturing method of the thin film photoelectric conversion apparatus of Claim 2 characterized by the above-mentioned. In the third step,
Oxidizing the surface of the photoelectric conversion layer to form a silicon oxide layer;
A removal step of selectively removing the silicon oxide layer;
The manufacturing method of the thin film photoelectric conversion apparatus of Claim 2 characterized by the above-mentioned. In the third step,
Flattening the surface of the photoelectric conversion layer;
Forming the second uneven shape on the planarized photoelectric conversion layer;
The manufacturing method of the thin film photoelectric conversion device of Claim 2 characterized by the above-mentioned. After additionally forming a new photoelectric conversion layer on the planarized photoelectric conversion layer, forming the second uneven shape on the surface of the new photoelectric conversion layer;
A method for producing a thin film photoelectric conversion device according to claim 6. In the second step and the third step, when forming the photoelectric conversion layer, a plurality of semiconductor films having a crystallization rate lower than the crystallization rate of the photoelectric conversion layer are inserted and formed in the photoelectric conversion layer. Relaxing the first uneven shape on the surface of the photoelectric conversion layer to form the second uneven shape on the surface of the photoelectric conversion layer,
The manufacturing method of the thin film photoelectric conversion apparatus of Claim 2 characterized by these.

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