Photoelectric conversion element, solar cell module, and paddle

Abstract

Provided is a photoelectric conversion element capable of maintaining photoelectric conversion element performance under a high-temperature and high-humidity environment. A photoelectric conversion element (10) comprises: at least one photoelectric conversion layer (26); a conductive layer (24) electrically connected to the photoelectric conversion layer; a first sealing layer (40) on the conductive layer; and a second sealing layer (41) on the first sealing layer. The first sealing layer (40) contains at least one from among an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride. The second sealing layer (41) includes a polymer layer or a nitride coating layer.

Description

Photoelectric conversion element, solar cell module and paddle

[0001] The present invention relates to a photoelectric conversion element, a solar cell module, and a paddle.

[0002] Types of photoelectric conversion elements such as solar cells include crystalline photoelectric conversion elements and thin-film photoelectric conversion elements. Crystalline photoelectric conversion elements contain, for example, crystalline silicon as a photoelectric conversion layer. Thin-film photoelectric conversion elements contain, for example, amorphous silicon, a CIS-based or CIGS-based compound, or a compound having a perovskite structure (perovskite-type compound) as a photoelectric conversion layer. The following Cited Document 1 discloses a photoelectric conversion element containing a perovskite-type compound.

[0003] The photoelectric conversion element described in Cited Document 1 has a perovskite layer as a photoelectric conversion layer, a hole transport layer (Spiro-MeOTAD) on the perovskite layer, and a sealing layer (protective film) on the hole transport layer. The sealing layer is formed of poly(chloro-p-xylene). Poly(chloro-p-xylene) has a relatively low water vapor permeability and high water repellency, which improves the humidity stability of the perovskite layer.

[0004] Hyojung Kim, et., al., Scientific Reports, vol. 9, 15461 (2019)

[0005] The inventors of the present application have discovered the following problem. When the sealing layer is made of an organic film such as poly(chloro-p-xylene), oxidation of the organic film may progress over long-term use. Oxidation of the organic film is particularly likely to progress in environments with high ultraviolet intensity and the presence of highly active atomic oxygen. On the other hand, when the sealing layer is made of an inorganic oxide layer, cracks that occur in the inorganic oxide layer may make it difficult to maintain the performance of the photoelectric conversion element in high-temperature, high-humidity environments.

[0006] Therefore, there is a demand for a photoelectric conversion element capable of maintaining its performance in a high-temperature, high-humidity environment, and for an item using such a photoelectric conversion element.

[0007] A photoelectric conversion element according to one embodiment includes at least one photoelectric conversion layer, a conductive layer electrically connected to the photoelectric conversion layer, a first sealing layer on the conductive layer, and a second sealing layer on the first sealing layer, wherein the first sealing layer includes at least one of an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride, and the second sealing layer includes a polymer layer or a nitride coating layer.

[0008] A solar cell module according to one aspect includes the above photoelectric conversion element.

[0009] A paddle according to one aspect includes the solar cell module described above.

[0010] FIG. 1 is a schematic plan view of a photoelectric conversion element according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the photoelectric conversion element taken along line 2A-2A in FIG. 1. FIG. 3 is a schematic cross-sectional view of a photoelectric conversion element according to the second embodiment. FIG. 4 is a schematic cross-sectional view of a photoelectric conversion element according to the third embodiment. FIG. 5 is a schematic cross-sectional view of a photoelectric conversion element according to the fourth embodiment. FIG. 6 is a schematic cross-sectional view of a photoelectric conversion element according to the fifth embodiment. FIG. 7 is a graph showing the characteristics of the photoelectric conversion elements according to Examples 1 and 2 and a Reference Example in a high-temperature, high-humidity test. FIG. 8 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to Example 1. FIG. 9 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to Example 2. FIG. 10 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to the Reference Example. FIG. 11 is a schematic plan view of a solar cell module including a photoelectric conversion element. FIG. 12 is a schematic perspective view of a satellite including a photoelectric conversion module.

[0011] Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the ratios of the dimensions may differ from those of the actual parts.

[0012] [First Embodiment] Fig. 1 is a schematic plan view of a photoelectric conversion element according to a first embodiment. Fig. 2 is a schematic cross-sectional view of the photoelectric conversion element taken along line 2A-2A in Fig. 1. It should be noted that for the sake of convenience in explaining the configuration of the photoelectric conversion element, a first sealing layer 40, a second sealing layer 41, and a barrier layer 48, which will be described later, are not shown in Fig. 1. The photoelectric conversion element 10 according to the first embodiment may be a thin-film type photoelectric conversion element. Preferably, the photoelectric conversion element 10 is a solar cell element that converts light energy into electrical energy.

[0013] The photoelectric conversion element 10 may have a film formation substrate 20 that serves as a base for forming each film. The film formation substrate 20 may be made of, for example, glass, ceramics, resin, or metal. The film formation substrate 20 may be a flexible substrate. The shape and dimensions of the film formation substrate 20 are determined appropriately depending on the size of the photoelectric conversion element 10, etc.

[0014] When a metal substrate is used as the deposition substrate 20, the deposition substrate 20 is formed of, for example, titanium (Ti), stainless steel (SUS), copper, aluminum, or an alloy thereof. Alternatively, the deposition substrate 20 may have a laminated structure in which multiple metal base materials are stacked. For example, a stainless steel foil, a titanium foil, or a molybdenum foil may be formed on the surface of the deposition substrate 20.

[0015] The photoelectric conversion element 10 may include at least a first conductive layer 22, a second conductive layer 24, and a photoelectric conversion layer 26 provided between the first conductive layer 22 and the second conductive layer 24. The first conductive layer 22, the photoelectric conversion layer 26, and the second conductive layer 24 are provided on a film formation substrate 20. The photoelectric conversion layer 26 is a layer that contributes to the mutual conversion of light energy and electrical energy. In a solar cell element that converts light energy into electrical energy, the photoelectric conversion layer 26 is sometimes called a light absorption layer.

[0016] The first conductive layer 22 and the second conductive layer 24 are layers that function as an anode or a cathode. The first conductive layer 22 and the second conductive layer 24 are adjacent to the photoelectric conversion layer 26 and are electrically connected to the photoelectric conversion layer 26. In this specification, the term "adjacent" means not only that both layers are in direct contact with each other, but also that both layers are close to each other via another layer.

[0017] The first conductive layer 22 is provided on the deposition substrate 20 and is provided between the photoelectric conversion layer 26 and the deposition substrate 20. The second conductive layer 24 is provided on the photoelectric conversion layer 26 and is located on the opposite side of the photoelectric conversion layer 26 from the deposition substrate 20. The second conductive layer 24 may be the distal conductive layer located farthest from the deposition substrate 20 in the thickness direction of the photoelectric conversion element 10 (the Z direction in the figure) among the conductive layers electrically connected to the photoelectric conversion layer 26.

[0018] In the first embodiment, the second conductive layer 24 may be composed of a transparent conductive layer. In this specification, the term "transparent conductive layer" refers to a conductive layer having light-transmitting properties. In this specification, "having light-transmitting properties" means that 10% or more of light having any wavelength between 200 nm and 2000 nm is transmitted through the second conductive layer 24. When the second conductive layer 24 is composed of a transparent conductive layer, light incident on or emitted from the photoelectric conversion layer 26 passes through the second conductive layer 24.

[0019] The first conductive layer 22 may be composed of an opaque conductive layer or a transparent conductive layer. The first conductive layer 22 may be formed of a metal such as molybdenum, titanium, or chromium. Although not particularly limited, the thickness of the first conductive layer 22 may be, for example, 50 nm to 1500 nm.

[0020] In the first embodiment, as a preferred example, the second conductive layer 24 may be formed of an n-type semiconductor, more specifically, a material having n-type conductivity and relatively low resistance. The second conductive layer 24 can function both as an n-type semiconductor and a transparent conductive layer. The second conductive layer 24 includes, for example, a metal oxide to which a Group III element (B, Al, Ga, or In) is added as a dopant. Here, the "group" of an element in this specification is based on the short periodic table (the same applies hereinafter).

[0021] The metal oxide constituting the second conductive layer 24 is, for example, indium tin oxide (In ２ O ３ : Sn), indium titanium oxide (In ２ O ３ :Ti), indium zinc oxide (In ２ O ３ :Zn), tin-zinc-doped indium oxide (In ２ O ３ : Sn, Zn), tungsten-doped indium oxide (In ２ O ３ :W), hydrogen-doped indium oxide (In ２ O ３ :H), indium gallium zinc oxide (InGaZnO ４ ), zinc tin oxide (ZnO:Sn), fluorine-doped tin oxide (SnO ２ :F), gallium-doped zinc oxide (ZnO:Ga), boron-doped zinc oxide (ZnO:B), aluminum-doped zinc oxide (ZnO:Al), and the like can be selected.

[0022] Although not particularly limited, the thickness of the second conductive layer 24 may be, for example, 500 nm to 2500 nm.

[0023] The photoelectric conversion layer 26 may include, for example, a p-type semiconductor. In a specific example, the photoelectric conversion layer 26 may function as, for example, a polycrystalline or microcrystalline p-type compound semiconductor layer.

[0024] In the first embodiment, the photoelectric conversion layer 26 includes a chalcogen compound layer. The chalcogen compound is a compound containing at least one chalcogen element. The chalcogen compound includes, for example, sulfide, selenide, and / or telluride. Specifically, the photoelectric conversion layer 26 includes a I-III-VI chalcogen compound having a chalcopyrite structure. ２ The photoelectric conversion layer 26 may include a group I compound semiconductor layer. Here, the group I element may be selected from copper (Cu), silver (Ag), gold (Au), etc. The group III element may be selected from indium (In), gallium (Ga), aluminum (Al), etc. Furthermore, the photoelectric conversion layer 26 may include tellurium (Te) as a group VI element in addition to selenium (Se) and sulfur (S). Furthermore, the photoelectric conversion layer 26 may include an alkali metal such as Li, Na, K, Rb, or Cs.

[0025] Instead, the photoelectric conversion layer 26 is made of I, which is a CZTS-based chalcogen compound containing Cu, Zn, Sn, S, or Se. ２ -(II-IV)-VI ４ A typical example of a CZTS-based chalcogen semiconductor is a Cu ２ ZnSnSe ４ , Cu ２ ZnSn(S,Se) ４ and the like.

[0026] The photoelectric conversion element 10 may have a first buffer layer 27a between the photoelectric conversion layer 26 and the first conductive layer 22, as needed. In this case, the first buffer layer 27a may be made of a semiconductor material having the same conductivity type as the first conductive layer 22, or may be made of a semiconductor material having a different conductivity type. The first buffer layer 27a may be made of a material having a higher electrical resistance than the first conductive layer 22.

[0027] The first buffer layer 27a is not particularly limited, and may be, for example, a layer containing a chalcogenide compound of a transition metal element having a layered structure. Specifically, the first buffer layer 27a may be composed of a compound made of a transition metal material such as M, W, Ti, V, Cr, Nb, or Ta and a chalcogen element such as O, S, or Se. The first buffer layer 27a may be, for example, M(Se,S) ２ Layer, MоSe ２ Layer or MoS ２ The first buffer layer 27 a can be formed on the surface of the first conductive layer 22 by chalcogenizing a precursor layer used as a precursor of the photoelectric conversion layer 26 .

[0028] The photoelectric conversion element 10 may have a second buffer layer 28a between the photoelectric conversion layer 26 and the second conductive layer 24, as needed. In this case, the second buffer layer 28a may be made of a semiconductor material having the same conductivity type as the second conductive layer 24, or may be made of a semiconductor material having a different conductivity type. The second buffer layer 28a may be made of a material having a higher electrical resistance than the second conductive layer 24.

[0029] The second buffer layer 28a is provided on the photoelectric conversion layer 26. Although not particularly limited, the thickness of the second buffer layer 28a may be, for example, 10 nm to 100 nm.

[0030] The second buffer layer 28a can be made of a compound selected from compounds containing zinc (Zn), cadmium (Cd), and indium (In). Examples of compounds containing zinc include ZnO, ZnS, and Zn(OH). ２ , or mixed crystals thereof such as Zn(O,S) and Zn(O,S,OH), as well as ZnMgO and ZnSnO. Compounds containing cadmium include, for example, CdS, CdO, or mixed crystals thereof such as Cd(O,S) and Cd(O,S,OH). Compounds containing indium include, for example, In ２ S ３ , In ２ O ３ or a mixed crystal thereof, In ２ (O, S) ３ , In ２(O, S, OH) ３ There is In ２ O ３ , In ２ S ３ , In(OH) ｘ The second buffer layer 28a may have a laminated structure of these compounds.

[0031] The second buffer layer 28 a has the effect of improving characteristics such as photoelectric conversion efficiency, but it can be omitted. When the second buffer layer 28 a is omitted, the second conductive layer 24 is formed directly on the photoelectric conversion layer 26.

[0032] It should be noted that the layered structure of the photoelectric conversion element 10 is not limited to the above embodiment and can take various forms. For example, the photoelectric conversion element 10 may have a configuration in which both an n-type semiconductor and a p-type semiconductor are sandwiched between a first conductive layer and a second conductive layer. In this case, the second conductive layer does not need to be composed of an n-type semiconductor. Furthermore, the photoelectric conversion element 10 is not limited to a p-n junction type structure, and may have a p-i-n junction type structure that includes an intrinsic semiconductor layer (i-type semiconductor) between an n-type semiconductor and a p-type semiconductor.

[0033] The photoelectric conversion element 10 may include a collecting electrode 30 on the second electrode layer 24. The collecting electrode 30 collects charge carriers from the second electrode layer 24 and is made of a conductive material. The collecting electrode 30 may be in direct contact with the second electrode layer 24. From the viewpoint of improving power generation efficiency, it is preferable that the area of ​​the collecting electrode 30 is as small as possible.

[0034] The collecting electrode 30 may have a plurality of substantially linear first portions 31 and second portions 32 connected to the first portions 31. The first portions 31 may also be referred to as "fingers." The second portions 32 may also be referred to as "bus bars."

[0035] The first portions 31 are arranged at intervals from one another. The plurality of linear first portions 31 are connected to the second portions 32. The first portions 31 serve to conduct electricity generated in the photoelectric conversion layer 26 to the second portions 32.

[0036] A plurality of first portions 31 of the collecting electrode 30 may be arranged side by side in the first direction (Y direction in the figure). The plurality of linear first portions 31 may be connected to the same second portion 32.

[0037] The second portion 32 of the collecting electrode 30 may extend in a first direction (Y direction in the figure). The second portion 32 may be connected to the first portion 31 at an end of the first portion 31. In this case, the multiple first portions 31 may extend from the second portion 32 along a second direction (X direction in the figure).

[0038] The second portions 32 of the collecting electrodes 30 may extend in the first direction (the Y direction in the figure) substantially from near one end to near the other end of the photoelectric conversion element 10. The width of the second portions 32 of the collecting electrodes 30 (the width in the X direction in the figure) may be larger than the width of each of the first portions 31 (the width in the Y direction in the figure).

[0039] The collecting electrode 30 (first portion 31 and second portion 32) may be made of a material having higher conductivity than the material constituting the second electrode layer 24. The material constituting the collecting electrode 30 is, for example, indium tin oxide (In ２ O ３ : Sn), indium titanium oxide (In ２ O ３ :Ti), indium zinc oxide (In ２ O ３ :Zn), tin-zinc-doped indium oxide (In ２ O ３ : Sn, Zn), tungsten-doped indium oxide (In ２ O ３ :W), hydrogen-doped indium oxide (In ２ O ３ :H), indium gallium zinc oxide (InGaZnO ４ ), zinc tin oxide (ZnO:Sn), fluorine-doped tin oxide (SnO ２The material can be selected from at least one of aluminum-doped zinc oxide (ZnO:Al), boron-doped zinc oxide (ZnO:B), gallium-doped zinc oxide (ZnO:Ga), Ni, Ti, Cr, Mo, Al, Ag, and Cu, or a compound containing one or more of these. The current collecting electrode 30 may be formed from an alloy or a laminate formed from a combination of the above-mentioned materials.

[0040] The photoelectric conversion element 10 may include a wiring 50 joined to the collecting electrode 30. The wiring 50 may be joined to the second portion 32 of the collecting electrode 30. The wiring 50 may be, for example, an interconnector for electrically connecting the photoelectric conversion element 10 to the outside, and / or a connector for connecting to a bypass diode that electrically bypasses a cell that cannot perform photoelectric conversion.

[0041] In the above-described embodiment, the photoelectric conversion element 10 includes the collecting electrodes 30 and the wiring 50. However, the collecting electrodes 30 and the wiring 50 are not essential components, and the photoelectric conversion element 10 does not necessarily have to include the collecting electrodes 30 and the wiring 50.

[0042] In the first embodiment, the photoelectric conversion element 10 has a first sealing layer 40 provided on the second conductive layer 24, a second sealing layer 41 provided on the first sealing layer 40, and a barrier layer 48. In a region where the first conductive layer 22, the photoelectric conversion layer 26, and the second conductive layer 24 are stacked one on top of the other, the first sealing layer 40 is located farther from the deposition substrate 20 in the thickness direction than the second conductive layer 24. In other words, the first sealing layer 40 is located outside the second conductive layer 24.

[0043] The first sealing layer 40 may be in contact with the surface of the second conductive layer 24 facing away from the photoelectric conversion layer 26. The first sealing layer 40 seals and protects the second conductive layer 24 and the photoelectric conversion layer 26. The first sealing layer 40 not only covers the surface of the second conductive layer 24 facing away from the photoelectric conversion layer 26, but may also cover the side surfaces of the second conductive layer 24, the photoelectric conversion layer 26 and / or the first conductive layer 22. The first sealing layer 40 may reach the side surface of the deposition substrate 20.

[0044] When the photoelectric conversion element 10 has a collecting electrode 30, the first sealing layer 40 preferably covers the collecting electrode 30. In this case, the first sealing layer 40 covers the collecting electrode 30 and the second conductive layer 24. A portion of the wiring 50 is covered by the first sealing layer 40, and the remaining portion of the wiring 50 may extend outside the first sealing layer 40.

[0045] When photoelectric conversion element 10 has collecting electrode 30, first sealing layer 40 covers steps on the upper surface of second conductive layer 24 caused by collecting electrode 30. The upper surface of first sealing layer 40 may be configured to be flatter than the steps on the upper surface of second conductive layer 24 caused by collecting electrode 30. In this way, first sealing layer 40 can function as a primer layer that contributes to reducing the steps at the interface. This makes it easier to appropriately form second sealing layer 41 on first sealing layer 40.

[0046] The first sealing layer 40 includes at least one of an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride. Preferably, the first sealing layer 40 includes Al ２ O ３ , SiO ２ , SiON, HfO ２ , ZrO ２ , TiO ２ , Ta ２ O ５ , Nb ２ O ５ , MgF ２ These materials are chemically stable and light-transmitting, and therefore suitable for the sealing layer.

[0047] The first sealing layer 40 can be formed by, for example, atomic layer deposition (ALD) and / or chemical vapor deposition (CVD) such as plasma CVD and inductively coupled plasma CVD. In particular, the ALD method is preferably used because of its excellent throwing power.

[0048] More preferably, the first sealing layer 40 contains an inorganic metal oxide obtained by oxidizing a precursor material. Examples of such inorganic metal oxides include Al ２ O ３, SiO ２ , HfO ２ , ZrO ２ , TiO ２ , Ta ２ O ５ and Nb ２ O ５ Inorganic metal oxides obtained by oxidizing precursor materials can be formed by ALD, which has excellent throwing power, and therefore can be suitably used to reduce the above-mentioned step.

[0049] It is preferable that the first sealing layer 40 has light-transmitting properties. From this viewpoint, the first sealing layer 40 is made of Al ２ O ３ or SiO ２ More preferably, these materials may also function as an oxygen barrier.

[0050] First sealing layer 40 preferably has a film thickness D1 of 5 nm or more and 100 nm or less. When first sealing layer 40 has a film thickness of 5 nm or more, second conductive layer 24 and photoelectric conversion layer 26 can be more reliably sealed. Furthermore, when first sealing layer 40 has a film thickness of 100 nm or less, it is believed that deterioration of sealing performance due to film stress can be mitigated.

[0051] The second sealing layer 41 is provided on the first sealing layer 40 and covers the first sealing layer 40. The second sealing layer 41 preferably has light-transmitting properties.

[0052] The second sealing layer 41 includes a polymer layer or a nitride coating layer. The polymer layer or nitride coating layer is excellent for sealing purposes because it is less likely to cause abnormalities such as point defects, cracks, and granular protrusions during coating.

[0053] The second sealing layer 41 can be formed by, for example, sputtering, ion plating, and / or chemical vapor deposition (CVD). The method for forming the second sealing layer 41 may be selected appropriately depending on the material of the second sealing layer 41. It is preferable not to use atomic layer deposition for forming the second sealing layer 41. This makes it possible to eliminate abnormalities in the first sealing layer 40, such as point defects, cracks, and granular protrusions, during the formation of the second sealing layer 41.

[0054] First sealing layer 40 made of the above-mentioned materials may have abnormal morphologies such as point defects, cracks, granular protrusions, etc. during film formation. These abnormal morphologies tend to penetrate or grow through first sealing layer 40 in the thickness direction, which may cause a decrease in the water vapor barrier property of first sealing layer 40.

[0055] The second sealing layer 41 may be designed to cover irregularities such as point defects, cracks, and granular protrusions in the first sealing layer 40 during coating, and to be thicker than the first sealing layer. This allows time for water vapor to diffuse in the film thickness direction, thereby suppressing a decrease in water vapor barrier properties. Furthermore, the second sealing layer 41 is preferably formed so as to penetrate into the point defects and cracks in the first sealing layer 40 and seal the point defects and cracks.

[0056] From the viewpoint of more reliably covering abnormalities in the first sealing layer 40, it is preferable that the film thickness D2 of the second sealing layer 41 be greater than the film thickness D1 of the first sealing layer 40. The second sealing layer 41 preferably has a film thickness D2 of, for example, 50 nm or more and 10,000 nm or less. When the second sealing layer 41 is 50 nm or more, the abnormalities in the first sealing layer 40 are more reliably covered, and a decrease in sealing performance due to the abnormalities in the first sealing layer 40 can be suppressed. Furthermore, when the second sealing layer 41 is 10,000 nm or less, the film stress of the second sealing layer 41 is reduced, and it is possible to suppress the second sealing layer 41 itself from cracking or peeling off.

[0057] The second sealing layer 41 is preferably made of a material having a relatively high water vapor barrier property. From this viewpoint, the second sealing layer 41 is preferably made of a material such as a paraxylylene-based polymer, polysilazane, perhydropolysilazane (PHPS), or SiNｘ and TiN ｘ It is preferable that the composition contains at least one selected from the group consisting of:

[0058] More preferably, second sealing layer 41 contains a paraxylylene-based polymer as a main component. Paraxylylene-based polymers have relatively low moisture permeability among polymer materials, making them suitable for protecting second conductive layer 24, photoelectric conversion layer 26, and the like from moisture. Furthermore, polymer layers such as paraxylylene-based polymers have the advantage of being less likely to develop abnormal morphologies such as those described above during coating. Furthermore, paraxylylene-based polymers are superior in terms of heat resistance compared to other polymers used to form sealing materials.

[0059] For example, the following polymers can be used as paraxylylene-based polymers. The following chemical formula (1) is a polymer with a linear structure that does not have a functional group on the aromatic ring. The following chemical formula (2) is a polymer in which one of the aromatic ring hydrogens is substituted with chlorine. The following chemical formula (3) is a polymer in which one of the aromatic ring hydrogens is substituted with a methyl group. The following chemical formula (4) is a polymer in which one of the methylene groups is fluorinated. The following chemical formula (5) is a polymer in which the hydrogens at the 2- and 5-positions of the aromatic ring are substituted with chlorine. The following chemical formula (6) is a polymer in which two of the methylene groups are fluorinated.

[0060] The paraxylylene-based polymer described above is translucent, and therefore can be suitably used even when light enters or exits the photoelectric conversion layer 26 from the second conductive layer 24 side.

[0061] The refractive index of the first sealing layer 40 at a wavelength of 589.3 nm is preferably greater than the refractive index of the second sealing layer 41 at a wavelength of 589.3 nm. Furthermore, the refractive index of the first sealing layer 40 at a wavelength of 589.3 nm is preferably smaller than the refractive index of the second conductive layer 24 at a wavelength of 589.3 nm. This suppresses light reflection at the interface between the second sealing layer 41 and the first sealing layer 40, and at the interface between the first sealing layer 40 and the second conductive layer 24. This allows light to reach the photoelectric conversion layer 26 more effectively.

[0062] For example, the material forming the second sealing layer 41 is a paraxylylene-based polymer, the material forming the second conductive layer 24 is indium tin oxide (ITO), and the material forming the first sealing layer 40 is aluminum oxide (Al ２ O ３ ) the refractive index relationship described above can be realized.

[0063] In the first embodiment, the photoelectric conversion element 10 has a barrier layer 48 provided on at least the upper surface of the second sealing layer 41. The barrier layer 48 may cover not only the upper surface of the second sealing layer 41 but also the side surfaces of the second sealing layer 41. The barrier layer 48 preferably covers the entire second sealing layer 41. The barrier layer 48 does not need to be electrically connected to the second conductive layer 24 or the photoelectric conversion element 26.

[0064] The barrier layer 48 is a layer having oxygen barrier properties. The oxygen permeability of the barrier layer 48 is preferably lower than that of the second sealing layer 41. From this perspective, the barrier layer 48 contains at least one of an inorganic metal oxide, an inorganic metal nitride, and an inorganic metal oxynitride, or a precursor thereof. Preferably, the barrier layer 48 contains an oxide, nitride, or oxynitride of silicon, aluminum, or indium tin as a main component. More preferably, the barrier layer 48 has water vapor barrier properties.

[0065] Specifically, the compounds constituting the barrier layer 48 are, for example, ITO and TiO ｘ , SiO ２ -Al ２ O ３ , AlO ｘ , AlON, SiOｘ , SiON, SiN, Y ２ O ３ , ZrO ２ , CaO, MgO, Ga ２ O ３ , MnO ２ , and CeO ２ The present invention may have at least one selected from the group consisting of:

[0066] Such barrier layer 48 is difficult for oxygen or atomic oxygen to permeate, and can suppress oxidation of first sealing layer 40 and second sealing layer 41. In particular, even when second sealing layer 41 includes a polymer layer, barrier layer 48 can suppress oxidation of the polymer layer.

[0067] The barrier layer 48 preferably has light-transmitting properties. The compounds listed above as materials for forming the barrier layer 48 generally have light-transmitting properties. If the barrier layer 48, the first sealing layer 40, the second sealing layer 41, and the second conductive layer 24 have light-transmitting properties, light can pass through the barrier layer 48, the first sealing layer 40, the second sealing layer 42, and the second conductive layer 24 to enter the photoelectric conversion layer 26 or exit the photoelectric conversion layer 26.

[0068] As described above, the barrier layer 48 may be a precursor of at least one of inorganic metal oxides, inorganic metal nitrides, and inorganic metal oxynitrides. For example, precursors of silicon dioxide, silicon nitride, and / or silicon oxynitride include siloxane and polysilazane. Siloxane is a compound having a Si—O—Si bond and a skeleton of silicon and oxygen. Polysilazane is a compound having a structure of “—(SiH ２ It is a polymer with the basic unit "(NH)-".

[0069] Siloxane and polysilazane are converted to silicon dioxide (SiO ２ It is known that the barrier layer 48 forms silicon dioxide (SiO ), silicon nitride (SiN ), and / or silicon oxynitride (SiO N ). Therefore, when the barrier layer 48 contains siloxane or polysilazane, the barrier layer 48 of the photoelectric conversion element 10 is exposed to atomic oxygen and then converted to silicon dioxide (SiO ). ２), silicon nitride (SiN) and / or silicon oxynitride (SiON). ２ ), silicon nitride (SiN) and / or silicon oxynitride (SiON) are suitable for oxygen barrier purposes as previously mentioned.

[0070] The photoelectric conversion element 10 may not include a glass layer such as a cover glass on the second conductive layer 24, i.e., outside the second conductive layer 24. If a glass layer such as a cover glass is provided, the weight of the photoelectric conversion element 10 increases and this causes a loss of flexibility of the photoelectric conversion element 10. In the above embodiment, the first sealing layer 40, the second sealing layer 41, and the barrier layer 48 can be used as a substitute for a glass layer such as a cover glass.

[0071] In the first embodiment, the barrier layer 48 forms the outermost surface of the photoelectric conversion element 10. Alternatively, another layer may be provided on the barrier layer 48 for the purpose of sealing and / or suppressing light reflection.

[0072] In the first embodiment, the photoelectric conversion element 10 including the photoelectric conversion layer 26 containing a CIS-based or CIGS-based compound has been mainly described. The photoelectric conversion layer 26 is not limited thereto and may contain any compound capable of forming a thin-film photoelectric conversion element.

[0073] For example, the photoelectric conversion element 10 may have an integrated structure in which a plurality of photoelectric conversion cells are integrated together. Alternatively, the photoelectric conversion element 10 may be a so-called tandem-type photoelectric conversion element having a structure in which two photoelectric conversion cells are stacked together. A tandem-type photoelectric conversion element includes a plurality of photoelectric conversion layers 26, typically two photoelectric conversion layers 26.

[0074] The photoelectric conversion element 10 according to the first embodiment has high moisture resistance and high oxidation resistance. In particular, resistance to highly active atomic oxygen can also be improved. Therefore, the photoelectric conversion element 10 can be suitably mounted in electrical equipment located at relatively high altitudes above the Earth and / or in outer space. Examples of such electrical equipment include floating objects, moving objects, and flying objects such as balloons, airplanes, rockets, and space stations. However, it should be noted that the uses of the photoelectric conversion element 10 are not limited to these uses, and it can also be used for terrestrial applications, for example.

[0075] [Second embodiment] Fig. 3 is a schematic cross-sectional view of a photoelectric conversion element according to a second embodiment. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals. It should be noted that the same components as those in the first embodiment are denoted by the same reference numerals.

[0076] The photoelectric conversion element 10 according to the second embodiment does not have the barrier layer 48 described in the first embodiment. Therefore, the second sealing layer 41 is located on the outermost surface of the photoelectric conversion element 10. The other configurations are the same as those of the first embodiment.

[0077] [Third Embodiment] Fig. 4 is a schematic cross-sectional view of a photoelectric conversion element according to a third embodiment. In the third embodiment, the same components as those in the previously described embodiments are denoted by the same reference numerals. It should be noted that the same components as those in the previously described embodiments are denoted by the same reference numerals.

[0078] The photoelectric conversion element 10 according to the third embodiment has a third sealing layer 42 on the second sealing layer 41 described in the first embodiment. The third sealing layer 42 covers the second sealing layer 41. This allows the third sealing layer 42 to contribute to suppressing oxidation of the second sealing layer 41.

[0079] The third sealing layer 42 includes at least one of an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride. Preferably, the third sealing layer 42 includes Al ２ O ３ , SiO ２ , SiON, HfO ２ , ZrO ２ , TiO２ , Ta ２ O ５ , Nb ２ O ５ , MgF ２ These materials are chemically stable and light-transmitting, and therefore suitable for the sealing layer.

[0080] The third sealing layer 42 can be formed by, for example, atomic layer deposition (ALD) and / or chemical vapor deposition (CVD) such as plasma CVD and inductively coupled plasma CVD. In particular, the ALD method is preferably used because of its excellent throwing power.

[0081] More preferably, the third sealing layer 42 contains an inorganic metal oxide obtained by oxidizing a precursor material. Examples of such inorganic metal oxides include Al ２ O ３ , SiO ２ , HfO ２ , ZrO ２ , TiO ２ , Ta ２ O ５ and Nb ２ O ５ Inorganic metal oxides obtained by oxidizing precursor materials can be formed by the ALD method, which has excellent throwing power. Therefore, the inorganic metal oxides can be suitably used to further reduce the surface irregularities of second sealing layer 41.

[0082] It is preferable that the third sealing layer 42 has light-transmitting properties. From this viewpoint, the third sealing layer 42 is made of Al ２ O ３ or SiO ２ More preferably, these materials may also function as an oxygen barrier.

[0083] Third sealing layer 42 preferably has a thickness of, for example, 5 nm or more and 100 nm or less. By making third sealing layer 42 5 nm or more, higher sealing performance can be obtained. By making third sealing layer 42 100 nm or less, film stress is reduced, and it is possible to suppress the formation of abnormalities that are undesirable for sealing performance, such as cracks, peeling, or grain growth.

[0084] During film formation, abnormalities such as those described above may form in third sealing layer 42. However, because third sealing layer 42 is formed on second sealing layer 41, where abnormalities are less likely to occur, abnormalities formed in third sealing layer 42 are usually formed in positions different from the positions of abnormalities formed in first sealing layer 40. Therefore, deterioration of the water vapor barrier property due to abnormalities penetrating the entire sealing layer or growing in the thickness direction is suppressed.

[0085] The photoelectric conversion element 10 according to the third embodiment does not have the barrier layer 48 described in the first embodiment. Instead, the photoelectric conversion element 10 may have the barrier layer 48 on the third sealing layer 42.

[0086] 5 is a schematic cross-sectional view of a photoelectric conversion element according to a fourth embodiment. In the fourth embodiment, the same components as those in the previously described embodiments are denoted by the same reference numerals. It should be noted that the same components as those in the previously described embodiments are denoted by the same reference numerals.

[0087] The photoelectric conversion element 10 according to the fourth embodiment has a fourth sealing layer 43 on the third sealing layer 42 described in the third embodiment. The fourth sealing layer 43 covers the third sealing layer 42. The fourth sealing layer 43 is preferably light-transmitting.

[0088] The fourth sealing layer 43 includes a polymer layer or a nitride coating layer, which is excellent for sealing purposes because the polymer layer or nitride coating layer is less likely to cause the above-mentioned abnormalities during coating.

[0089] Fourth sealing layer 43 can be formed by, for example, sputtering, ion plating, and / or chemical vapor deposition (CVD). The method for forming fourth sealing layer 43 may be selected appropriately depending on the material of fourth sealing layer 43. However, it is preferable not to use atomic layer deposition for forming fourth sealing layer 43. This can reduce the possibility of abnormalities occurring in fourth sealing layer 43 during formation of fourth sealing layer 43.

[0090] Third sealing layer 42 may have an abnormal morphology during deposition. The abnormal morphology may easily penetrate or grow through third sealing layer 42 in the thickness direction, which may cause a decrease in the water vapor barrier property of third sealing layer 42.

[0091] Since fourth sealing layer 43 is less likely to have defects such as abnormalities during coating, it covers the abnormalities formed in third sealing layer 42. This makes it possible to prevent a decrease in the water vapor barrier property.

[0092] From the viewpoint of more reliably covering abnormalities in third sealing layer 42, the film thickness of fourth sealing layer 43 is preferably larger than the film thickness of third sealing layer 42. Fourth sealing layer 43 preferably has a film thickness of, for example, 50 nm or more and 10,000 nm or less. When fourth sealing layer 43 is 50 nm or more, abnormalities in third sealing layer 42 are more reliably covered, and a decrease in sealing performance due to abnormalities in third sealing layer 42 can be suppressed. Furthermore, when fourth sealing layer 43 is 10,000 nm or less, the film stress of fourth sealing layer 43 is reduced, and it is possible to suppress cracks in fourth sealing layer 43 itself and peeling of fourth sealing layer 43.

[0093] The fourth sealing layer 43 is preferably made of a material having a relatively high water vapor barrier property. From this viewpoint, the fourth sealing layer 43 is preferably made of a material having a relatively high water vapor barrier property, such as a paraxylylene-based polymer, polysilazane, perhydropolysilazane (PHPS), SiN ｘ and TiN ｘ It is preferable that the composition contains at least one selected from the group consisting of:

[0094] More preferably, fourth sealing layer 43 contains a paraxylylene-based polymer as a main component. The advantages, chemical formula, etc. of the paraxylylene-based polymer are as described in the first embodiment.

[0095] The photoelectric conversion element 10 according to the fourth embodiment does not have the barrier layer 48 described in the first embodiment. Instead, the photoelectric conversion element 10 may have the barrier layer 48 on the fourth sealing layer 43.

[0096] 6 is a schematic cross-sectional view of a photoelectric conversion element according to a fifth embodiment. In the fifth embodiment, the same components as those in the previously described embodiments are denoted by the same reference numerals. It should be noted that the same components as those in the previously described embodiments are denoted by the same reference numerals.

[0097] Photoelectric conversion element 10 according to the fifth embodiment has fifth sealing layer 44 on fourth sealing layer 43 described in the fourth embodiment. Fifth sealing layer 44 covers fourth sealing layer 43. This allows fifth sealing layer 44 to contribute to suppressing oxidation of fourth sealing layer 43.

[0098] The fifth sealing layer 44 includes at least one of an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride. Preferably, the fifth sealing layer 44 includes Al ２ O ３ , SiO ２ , SiON, HfO ２ , ZrO ２ , TiO ２ , Ta ２ O ５ , Nb ２ O ５ , MgF ２ These materials are chemically stable and light-transmitting, and therefore suitable for the sealing layer.

[0099] The fifth sealing layer 44 can be formed by, for example, atomic layer deposition (ALD) and / or chemical vapor deposition (CVD) such as plasma CVD and inductively coupled plasma CVD. In particular, the ALD method is preferably used because of its excellent throwing power.

[0100] More preferably, the fifth sealing layer 44 contains an inorganic metal oxide obtained by oxidizing a precursor material. Examples of such inorganic metal oxides include Al ２ O ３ , SiO ２ , HfO ２ , ZrO ２ , TiO ２ , Ta ２ O ５ and Nb ２ O ５ The inorganic metal oxide obtained by oxidizing the precursor material can be formed by the ALD method, which has excellent throwing power. Therefore, the inorganic metal oxide can be suitably used to reduce the irregularities on the surface of the fourth sealing layer 43.

[0101] The fifth sealing layer 44 preferably has light-transmitting properties. From this viewpoint, the fifth sealing layer 44 is preferably made of Al ２ O ３ or SiO ２ More preferably, these materials may also function as an oxygen barrier.

[0102] Fifth sealing layer 44 preferably has a thickness of, for example, 5 nm or more and 100 nm or less. By making fifth sealing layer 44 5 nm or more, higher sealing performance can be obtained. By making fifth sealing layer 44 100 nm or less, film stress is reduced, and it is possible to suppress the formation of abnormalities that are undesirable for sealing performance, such as cracks, peeling, or grain growth.

[0103] During film formation, the above-described abnormal morphology may be formed in fifth sealing layer 44. However, because fifth sealing layer 44 is formed on fourth sealing layer 43, where abnormal morphology is less likely to occur, the abnormal morphology formed in fifth sealing layer 44 is usually formed at a position different from the position of the abnormal morphology formed in first sealing layer 40 or third sealing layer 42. Therefore, a decrease in the water vapor barrier property due to the abnormal morphology penetrating the entire sealing layer or growing in the thickness direction is suppressed.

[0104] The photoelectric conversion element 10 according to the fifth embodiment does not have the barrier layer 48 described in the first embodiment. Instead, the photoelectric conversion element 10 may have the barrier layer 48 on the fifth sealing layer 44.

[0105] [Examples] (Example 1) A photoelectric conversion element according to Example 1 will be described. The photoelectric conversion element according to Example 1 has the configuration described in the second embodiment (see FIG. 3). The film formation substrate 20 is a titanium thin film. The first conductive layer 22 contains molybdenum. The first buffer layer 27, the photoelectric conversion layer 26, and the second buffer layer 28 have a so-called CIGS-based layer structure. The second electrode layer 24 is a transparent conductive film. A collecting electrode 30 is formed on the second electrode layer 24.

[0106] In the first embodiment, the first sealing layer 40 is made of aluminum oxide (Al ２ O ３ ). First sealing layer 40 was formed by an ALD method at a temperature of 150°C. The film thickness of first sealing layer 40 was approximately 30 nm. Second sealing layer 41 included a paraxylylene-based polymer (the above-mentioned chemical formula (2): Parylene C). Second sealing layer 41 was formed by a vapor deposition method under a temperature condition of 690°C. The film thickness of second sealing layer 41 was approximately 50 nm.

[0107] Example 2 A photoelectric conversion element according to Example 2 will be described. The photoelectric conversion element according to Example 2 has the configuration described in the third embodiment (see FIG. 4). The configurations of the film-formation substrate 20, the first conductive layer 22, the first buffer layer 27, the photoelectric conversion layer 26, the second buffer layer 28, the second electrode layer 24, and the collecting electrode 30 are the same as those of Example 1.

[0108] In Example 2, the first sealing layer 40 and the second sealing layer 41 were made of the same material as in Example 1, and were formed under the same conditions and by the same method as in Example 1. The film thickness of the first sealing layer 40 was about 30 nm. The film thickness of the second sealing layer 41 was about 50 nm. In Example 2, the third sealing layer 42 was made of aluminum oxide (Al ２ O ３ Third sealing layer 42 was formed on second sealing layer 41 by ALD at a temperature of 150° C. The film thickness of third sealing layer 42 was about 30 nm.

[0109] (Reference Example) A photoelectric conversion element according to the Reference Example will be described. The photoelectric conversion element according to the Reference Example has the same configuration as the photoelectric conversion element according to Example 1, except that it does not have the first sealing layer 40. That is, in the photoelectric conversion element according to the Reference Example, the second sealing layer 41 is provided directly on the second electrode layer 24 and the collecting electrode 30. In the Reference Example, the second sealing layer 41 is made of the same material as the second sealing layer 41 in Example 1, and was formed under the same conditions and by the same method as in Example 1. The film thickness of the second sealing layer 41 was approximately 50 nm.

[0110] [High-Temperature, High-Humidity Test] A high-temperature, high-humidity test was conducted on the photoelectric conversion elements according to Examples 1 and 2 and the Reference Example. The high-temperature, high-humidity test was conducted in accordance with IEC 61215 (10.13 Damp-heat test). In the high-temperature, high-humidity test, the temperature was 45°C and the humidity was 90%.

[0111] The performance of the photoelectric conversion elements according to Examples 1 and 2 and the Reference Example was evaluated before and during the high-temperature, high-humidity test. Specifically, the photoelectric conversion elements according to Examples 1 and 2 and the Reference Example were evaluated for the photoelectric conversion efficiency retention rate (Eff retention rate), fill factor retention rate (FF retention rate), open-circuit voltage retention rate (Voc retention rate), and short-circuit current density retention rate (Jsc retention rate).

[0112] The photoelectric conversion efficiency retention rate is the value obtained by dividing the photoelectric conversion efficiency of the photoelectric conversion element during the high-temperature, high-humidity test by the photoelectric conversion efficiency of the photoelectric conversion element before the high-temperature, high-humidity test. The fill factor retention rate is the value obtained by dividing the fill factor of the photoelectric conversion element during the high-temperature, high-humidity test by the fill factor of the photoelectric conversion element before the high-temperature, high-humidity test. The open-circuit voltage retention rate is the value obtained by dividing the open-circuit voltage of the photoelectric conversion element during the high-temperature, high-humidity test by the open-circuit voltage of the photoelectric conversion element before the high-temperature, high-humidity test. The short-circuit current density retention rate is the value obtained by dividing the short-circuit current density of the photoelectric conversion element during the high-temperature, high-humidity test by the short-circuit current density of the photoelectric conversion element before the high-temperature, high-humidity test. Therefore, the values ​​of these retention rates are "1" for the photoelectric conversion element before the high-temperature, high-humidity test.

[0113] FIG. 7 is a graph showing the characteristics of the photoelectric conversion elements according to Examples 1 and 2 and the Reference Example in a high-temperature, high-humidity test. In FIG. 7, the vertical axis represents the value of each of the above-mentioned retention rates. The horizontal axis represents the test time. From FIG. 7, it can be seen that the retention rates of photoelectric conversion efficiency, fill factor, open-circuit voltage, and short-circuit current density generally decrease with test time. However, in the photoelectric conversion elements according to Examples 1 and 2, the rate of decrease with test time is less than that of the Reference Example. In particular, the decrease in the retention rates of open-circuit voltage and short-circuit current density in Examples 1 and 2 is significantly suppressed compared to that of the Reference Example.

[0114] For Examples 1 and 2 and the Reference Example, the current-voltage characteristics of the photoelectric conversion elements were evaluated before the high-temperature, high-humidity test and 66 hours after the start of the high-temperature, high-humidity test. The measurements were carried out using a solar simulator at 1000 W / m ２ The test was carried out under conditions in which sunlight or simulated sunlight was irradiated onto the photoelectric conversion element. Fig. 8 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to Example 1. Fig. 9 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to Example 2. Fig. 10 is a graph showing the current-voltage characteristics of the photoelectric conversion element according to the reference example.

[0115] The photoelectric conversion elements of Examples 1 and 2 and the Reference Example all exhibited substantially equivalent current-voltage characteristics before the high-temperature, high-humidity test. In the photoelectric conversion element of the Reference Example, the current-voltage characteristics significantly decreased 66 hours after the start of the high-temperature, high-humidity test (see FIG. 9). In contrast, in the photoelectric conversion element of Example 1, the decrease in the current-voltage characteristics 66 hours after the start of the high-temperature, high-humidity test was minimal (see FIG. 7). Therefore, it can be seen that sealing with both the first sealing layer 40 and the second sealing layer 41 is effective in maintaining the performance of the photoelectric conversion element in a high-temperature, high-humidity environment.

[0116] Furthermore, the current-voltage characteristics of the photoelectric conversion element according to Example 2 showed almost no deterioration 66 hours after the start of the high-temperature, high-humidity test. Therefore, it is clear that sealing by first sealing layer 40, second sealing layer 41, and third sealing layer 42 is significantly effective in maintaining the performance of the photoelectric conversion element in a high-temperature, high-humidity environment.

[0117] [Solar Cell Module] Next, a solar cell module including a photoelectric conversion element will be described. Fig. 11 is a schematic plan view of a solar cell module including a photoelectric conversion element. The solar cell module 100 may include one or more photoelectric conversion elements 10. Note that Fig. 11 shows a photoelectric conversion module 100 including a plurality of photoelectric conversion elements 10.

[0118] When the photoelectric conversion module 100 includes a plurality of photoelectric conversion elements 10, the plurality of photoelectric conversion elements 10 may be arranged in at least one direction, preferably in a lattice pattern. In this case, the plurality of photoelectric conversion elements 10 may be electrically connected to each other in series and / or parallel.

[0119] In the example shown in Fig. 11 , the photoelectric conversion elements 10 are arranged so as to partially overlap each other. Among the photoelectric conversion elements 10 arranged in one direction, adjacent photoelectric conversion elements 10 partially overlap each other. Specifically, as shown in Fig. 11 , a certain photoelectric conversion element 10 may be arranged so as to cover the second portion 32 of the collecting electrode 30 of the adjacent photoelectric conversion element 10. In this case, the photoelectric conversion element 10 is electrically connected to the second portion 32 of the collecting electrode 30 of the adjacent photoelectric conversion element 10.

[0120] 11 , adjacent photoelectric conversion elements 10 may be arranged with a gap between them. In this case, the photoelectric conversion module 100 may include wiring 50 that electrically connects the second portion 32 of the collecting electrode 30 of a certain photoelectric conversion element 10 to the adjacent photoelectric conversion element 10.

[0121] [Satellite and Paddle for Satellite] Next, a satellite equipped with a solar cell module and a paddle for the satellite will be described. Fig. 12 is a schematic perspective view of a satellite equipped with a solar cell module. The satellite 900 may have a base 910 and a paddle 920. The base 910 may include equipment (not shown) necessary for controlling the satellite 900. An antenna 940 may be attached to the base 910.

[0122] The paddle 920 may include the solar cell module 100 described above. The paddle 920 including the solar cell module 100 can be used as a power source for operating various devices provided on the base 910. In this way, the solar cell module 100 can be applied to a paddle for a satellite. In particular, since the paddle 920 for a satellite is exposed to a high temperature environment and an environment with drastic temperature changes during launch and operation of the satellite, it is desirable to use the solar cell module 100 including the photoelectric conversion element 10 having high heat resistance described above.

[0123] The paddle 920 may have a connecting portion 922 and a hinge portion 924. The connecting portion 922 corresponds to the portion that connects the paddle 920 to the base portion 910.

[0124] The hinge portion 924 extends in one direction, allowing the paddle 920 to be folded around the hinge portion 924 as a rotation axis. Each paddle 920 may have at least one, and preferably a plurality of, hinge portions 924. This allows the paddle 920 equipped with the solar cell module 100 to be foldable into a small size. When the satellite 900 is launched, the paddle 920 may be in a folded state. The paddle 920 may be unfolded when receiving sunlight to generate power.

[0125] 12, the paddle 920 may have a cylindrical shape formed by being wound. This allows the paddle 920 to assume a generally flat, deployed state by rotating the wound portion. When the satellite 900 is launched, the paddle 920 may maintain a generally cylindrical shape. The paddle 920 may be deployed to a generally flat state when receiving sunlight and generating power.

[0126] It should be noted that each feature described in each of the above-described embodiments can be applied to or exchanged with another embodiment, whenever possible.

[0127] As described above, the contents of the present invention have been disclosed through the embodiments, but the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. Therefore, the technical scope of the present invention is defined only by the inventive features of the claims that can be reasonably understood from the above description.

[0128] This application claims priority to Japanese Patent Application No. 2023-126459, filed on August 2, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. At least one photoelectric conversion layer, A conductive layer electrically connected to the photoelectric conversion layer, The first sealing layer on the conductive layer, The first sealing layer has a second sealing layer, The first sealing layer comprises at least one of inorganic metal oxides, inorganic metal nitrides, inorganic metal oxynitrides, and inorganic metal fluorides. The second sealing layer includes a polymer layer or a nitride coating layer. The first sealing layer is a photoelectric conversion element that covers at least a portion of the side surface of the photoelectric conversion layer.

2. The photoelectric conversion element according to claim 1, wherein the second sealing layer comprises a paraxylylene polymer.

3. The photoelectric conversion element according to claim 1, wherein the first sealing layer comprises an inorganic metal oxide.

4. The photoelectric conversion element according to claim 1, wherein the first sealing layer has a film thickness of 5 nm or more and 100 nm or less.

5. The first sealing layer has an abnormal shape, The photoelectric conversion element according to claim 1, wherein the second sealing layer covers the abnormal shape.

6. The photoelectric conversion element according to claim 1, wherein the refractive index of the first sealing layer at a wavelength of 589.3 nm is greater than the refractive index of the second sealing layer at a wavelength of 589.3 nm.

7. The photoelectric conversion element according to claim 1, wherein the refractive index of the first sealing layer at a wavelength of 589.3 nm is smaller than the refractive index of the conductive layer at a wavelength of 589.3 nm.

8. Having a third sealing layer on the second sealing layer, The photoelectric conversion element according to claim 1, wherein the third sealing layer comprises at least one of inorganic metal oxides, inorganic metal nitrides, inorganic metal oxynitrides, and inorganic metal fluorides.

9. Having a fourth sealing layer on the third sealing layer, The photoelectric conversion element according to claim 8, wherein the fourth sealing layer includes a polymer layer or a nitride coating layer.

10. Having a fifth sealing layer on the fourth sealing layer, The photoelectric conversion element according to claim 9, wherein the fifth sealing layer comprises at least one of an inorganic metal oxide, an inorganic metal nitride, an inorganic metal oxynitride, and an inorganic metal fluoride.

11. A solar cell module comprising a photoelectric conversion element according to any one of claims 1 to 10.

12. A paddle comprising the solar cell module according to claim 11.