Photoelectric conversion element and method for manufacturing photoelectric conversion element

Abstract

Provided is a method for manufacturing a photoelectric conversion element that makes it possible to improve the connection reliability of a conductor. This method for manufacturing a photoelectric conversion element comprises: a step for forming, above a first electrode layer (22), a photoelectric conversion layer (26) having a chalcogen compound; a step for removing a portion of the photoelectric conversion layer (26); and a step for etching the surface of the first electrode layer (22) in a region from which at least a portion of the photoelectric conversion layer (26) has been removed.

Description

Photoelectric conversion element and method for manufacturing a photoelectric conversion element

[0001] The present invention relates to a photoelectric conversion element and a method for manufacturing a photoelectric conversion element.

[0002] A photoelectric conversion element that converts light energy into electrical energy is known (see Patent Document 1 below). The photoelectric conversion element described in Patent Document 1 has a so-called CIS-type or CIGS-type photoelectric conversion layer. The photoelectric conversion layer is sandwiched between a pair of electrode layers (a first electrode layer and a second electrode layer). The CIS-type or CIGS-type photoelectric conversion layer has a chalcopyrite structure I-III-VI ２ It has a group compound semiconductor (chalcogen compound semiconductor). Such CIS-based or CIGS-based photoelectric conversion layers are formed by first depositing a precursor film consisting of group I (Cu, etc.) and group III (In, Ga, etc.), and then selenizing and / or sulfidizing the precursor film.

[0003] Japanese Patent Publication No. 2020-181922

[0004] Photoelectric conversion elements may have conductors such as wiring for extracting power generated by photoelectric conversion and connectors for electrically connecting to other photoelectric conversion elements. Such conductors are usually bonded to the first electrode layer and / or the second electrode layer. The inventors of the present application have newly discovered that in photoelectric conversion elements including a photoelectric conversion layer having a chalcogen compound semiconductor, the reliability of conductor connections may be reduced in some cases.

[0005] Therefore, there is a need for a photoelectric conversion element and a method for manufacturing the photoelectric conversion element that can improve the reliability of conductor connections.

[0006] A method for manufacturing a photoelectric conversion element according to one embodiment includes the steps of forming a photoelectric conversion layer having a chalcogen compound on a first electrode layer, removing a part of the photoelectric conversion layer, and etching the surface of the first electrode layer in the region where at least a part of the photoelectric conversion layer has been removed.

[0007] A photoelectric conversion element according to one embodiment includes a first electrode layer and a photoelectric conversion layer on the first electrode layer. The photoelectric conversion layer contains a chalcogen compound. The first electrode layer has a coated portion covered by the photoelectric conversion layer and an uncoated portion not covered by the photoelectric conversion layer. The uncoated portion of the first electrode layer has a deficient region that contains less chalcogen element than the amount of chalcogen element on the surface of the coated portion of the first electrode layer, or does not contain chalcogen element at all.

[0008] A photoelectric conversion module according to one embodiment includes the above-mentioned photoelectric conversion element.

[0009] A paddle according to one embodiment is equipped with the above-mentioned photoelectric conversion element.

[0010] Figure 1 is a schematic plan view of a photoelectric conversion element according to one embodiment. Figure 2 is a schematic side view of the photoelectric conversion element viewed from direction 2A in Figure 1. Figure 3 is a schematic cross-sectional view of the photoelectric conversion element along the line 3A-3A in Figure 1. Figure 4 is a schematic plan view showing an example of the pattern of a deficient region on the surface of a first electrode layer with little or no chalcogen elements. Figure 5 is a schematic plan view showing another example of the pattern of a deficient region on the surface of a first electrode layer with little or no chalcogen elements. Figure 6 is a flowchart showing a method for manufacturing a photoelectric conversion element according to one embodiment. Figure 7 is a schematic cross-sectional view illustrating one step of the method for manufacturing a photoelectric conversion element according to one embodiment. Figure 8 is a schematic diagram illustrating the step following Figure 7. Figure 9 is a schematic diagram illustrating the step following Figure 8. Figure 10 is a schematic diagram illustrating the step following Figure 9. Figure 11 is a schematic diagram illustrating the step following Figure 10. Figure 12 is a schematic diagram illustrating the steps following Figure 11. Figure 13 is a schematic diagram illustrating the steps following Figure 12. Figure 14 is a graph showing the results of elemental emission spectra obtained by glow discharge emission analysis in the first electrode layer 22 without laser irradiation in Experimental Example 1. Figure 15 is a graph showing the results of elemental emission spectra obtained by glow discharge emission analysis in the first electrode layer 22 with laser irradiation in Experimental Example 1. Figure 16 is a graph showing the results of elemental emission spectra obtained by glow discharge emission analysis in the first electrode layer 22 without laser irradiation in Experimental Example 2. Figure 17 is a graph showing the results of elemental emission spectra obtained by glow discharge emission analysis in the first electrode layer 22 with laser irradiation in Experimental Example 2. Figure 18 is a schematic plan view of a photoelectric conversion module according to one embodiment. Figure 19 is a schematic perspective view of an artificial satellite equipped with a photoelectric conversion module.

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

[0012] [Photoelectric Conversion Element] Figure 1 is a schematic plan view of a photoelectric conversion element according to one embodiment. Figure 2 is a schematic side view of the photoelectric conversion element as seen from direction 2A in Figure 1. Figure 3 is a schematic cross-sectional view of the photoelectric conversion element along the line 3A-3A in Figure 1.

[0013] The photoelectric conversion element 10 according to this 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.

[0014] The photoelectric conversion element 10 may have a substrate 20 that serves as the base for depositing each film. The substrate 20 is a substrate on which the first electrode layer 22, the photoelectric conversion layer 26, and the second electrode layer 24, which will be described later, are deposited. The shape and dimensions of the substrate 20 are appropriately determined according to the size of the photoelectric conversion element 10, etc.

[0015] The photoelectric conversion element 10 may include at least a first electrode layer 22, a second electrode layer 24, and a photoelectric conversion layer 26 provided between the first electrode layer 22 and the second electrode layer 24. The photoelectric conversion element 10 may also have a first buffer layer 27 between the first electrode layer 22 and the photoelectric conversion layer 26. The photoelectric conversion element 10 may have a structure in which the first electrode layer 22, the first buffer layer 27, the photoelectric conversion layer 26, and the second electrode layer 24 are stacked in this order on a substrate 20.

[0016] The first electrode layer 22 is provided between the photoelectric conversion layer 26 and the substrate 20. When the second electrode layer 24 is composed of a transparent electrode layer, the first electrode layer 22 may be composed of an opaque electrode layer or a transparent electrode layer. The first electrode layer 22 may contain, for example, at least one transition metal material selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), vanadium (V), chromium (Cr), niobium (Nb), and tantalum (Ta). Preferably, the first electrode layer 22 may contain molybdenum (Mo).

[0017] While not particularly limited, the thickness of the first electrode layer 22 may be, for example, 50 nm to 1500 nm, preferably 50 nm to 1200 nm, more preferably 50 nm to 800 nm, and even more preferably 50 nm to 500 nm.

[0018] The photoelectric conversion layer 26 is a layer that contributes to the mutual conversion between light energy and electrical energy. In a solar cell element that converts light energy into electrical energy, the photoelectric conversion layer 26 may be called a light absorption layer.

[0019] The second electrode layer 24 is located on the side opposite to the first electrode layer 22 with respect to the photoelectric conversion layer 26. The second electrode layer 24 may be constituted by a transparent electrode layer. When the second electrode layer 24 is constituted by a transparent electrode layer, light incident on the photoelectric conversion layer 26 or emitted from the photoelectric conversion layer 26 passes through the second electrode layer 24.

[0020] In the present embodiment, as a preferable example, the second electrode layer 24 may be formed of an n-type semiconductor, more specifically, a material having n-type conductivity and relatively low resistance. The second electrode layer 24 can also function as both an n-type semiconductor and a transparent electrode layer. The second electrode 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 description of "group" of elements in this specification is based on the short-period type periodic table (the same applies hereinafter).

[0021] Examples of the metal oxide constituting the second electrode layer 24 include ZnO or SnO ２ may be mentioned. The second electrode 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 <000​​​​​​: (F), it can be selected from gallium-doped zinc oxide (ZnO:Ga), boron-doped zinc oxide (ZnO:B), aluminum-doped zinc oxide (ZnO:Al), etc.

[0022] Although not particularly limited, the thickness of the second electrode layer 24 may be, for example, 0.5 μm to 2.5 μm.

[0023] The photoelectric conversion layer 26 may contain, 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 present embodiment, the photoelectric conversion layer 26 contains at least a Group I element and a Group III element. Specifically, the photoelectric conversion layer 26 may contain a chalcogen compound semiconductor containing at least a Group I element and a Group III element. The chalcogen compound semiconductor is a compound containing at least one chalcogen element. The chalcogen compound includes, for example, sulfides, selenides, and / or tellurides.

[0025] Specifically, the photoelectric conversion layer 26 may contain a Group I-III-VI ２ group compound semiconductor layer having a chalcopyrite structure. Here, the Group I element can be selected from copper (Cu), silver (Ag), gold (Au), etc. The Group III element can be selected from indium (In), gallium (Ga), aluminum (Al), etc. Also, the photoelectric conversion layer 26 may contain tellurium (Te) etc. in addition to selenium (Se) and sulfur (S) as the Group VI element.

[0026] Instead, the photoelectric conversion layer 26 is an I ２ -(II-IV)-VI ４ group compound semiconductor layer which is a CZTS-based chalcogen compound containing Cu, Zn, Sn, S or Se. Representative examples of the CZTS-based chalcogen compound semiconductor include those using compounds such as Cu ２ ZnSnSe ４ Cu ２ ZnSn(S,Se) ４ and the like. <The thickness of the photoelectric conversion layer 26 may be, for example, in the range of 0.5 μm to 5.0 μm, preferably in the range of 1.0 μm to 3.0 μm.

[0028] The photoelectric conversion element 10 may have a first buffer layer 27 between the photoelectric conversion layer 26 and the first electrode layer 22. In this case, the first buffer layer 27 may be a semiconductor material having the same conductivity type as the first electrode layer 22, or may be a semiconductor material having a different conductivity type. The first buffer layer 27 may be composed of a material having a higher electrical resistance than the first electrode layer 22.

[0029] The first buffer layer 27 is not particularly limited, but may be, for example, a layer containing a chalcogenide compound of a transition metal element. Specifically, the first buffer layer 27 may be composed of a compound containing a transition metal material such as Мо, W, Ti, V, Cr, Nb, Ta, etc. and a chalcogen element such as О, S, Se, etc.

[0030] In a specific example, the first buffer layer 27 is Мо(Se, S) ２ layer, МоSe ２ layer or МоS ２ layer, etc. The first buffer layer 27 may be formed on the surface of the first electrode layer 22 by the reaction of the material constituting the first electrode layer 22 and a chalcogen element when the precursor film, which is a precursor of the photoelectric conversion layer 26, is chalcogenated to form the photoelectric conversion layer​​​​​​​​The second buffer layer can be selected from compounds containing zinc (Zn), cadmium (Cd), and indium (In). Examples of zinc-containing compounds include ZnO, ZnS, and Zn(OH). ２ These include Zn(O,S), Zn(O,S,OH), and even ZnMgO and ZnSnO. Examples of cadmium-containing compounds include CdS, CdO, or their mixed crystals Cd(O,S) and Cd(O,S,OH). Examples of indium-containing compounds include In ２ S ３ In ２ O ３ , or these mixed crystals In ２ (O, S) ３ In ２ (O, S, OH) ３ Yes, ２ O ３ In ２ S ３ In (OH) ｘ These can be used. Furthermore, the second buffer layer may have a layered structure of these compounds.

[0034] The photoelectric conversion element 10 may include a plurality of photoelectric conversion cells 12 integrated on the surface side of the substrate 20 (see Figure 1). Here, the "surface side" corresponds to the light-receiving surface side into which light enters the photoelectric conversion element 10. The "back side" corresponds to the surface opposite to the surface side.

[0035] Each photoelectric conversion cell 12 may have a substantially strip-like shape when viewed from the thickness direction of the photoelectric conversion element 10, that is, the direction intersecting the light-receiving surface (the Z direction in the figure; the same applies hereinafter). Each photoelectric conversion cell 12 may extend for a long distance along the first direction (the Y direction in the figure; the same applies hereinafter). In addition, multiple photoelectric conversion cells 12 are arranged in a second direction (the X direction in the figure; the same applies hereinafter) that intersects the first direction.

[0036] Adjacent photoelectric conversion cells 12 may be separated from each other by a first groove P1, a second groove P2, and a third groove P3 extending in a first direction. That is, the boundary between each photoelectric conversion cell 12 is defined by the first groove P1, the second groove P2, and / or the third groove P3.

[0037] The first groove P1, the second groove P2, and / or the third groove P3 are formed in the first electrode layer 22, the first buffer layer 27, the photoelectric conversion layer 26, and / or the second electrode layer 24 described above, and these layers 22, 27, 26, and 24 are divided for each photoelectric conversion cell 12.

[0038] More specifically, the first electrode layers 22 belonging to adjacent photoelectric conversion cells 12 are electrically separated from each other by the first groove P1. As a result, the first electrode layers 22 of adjacent photoelectric conversion cells 12 are not directly electrically connected to each other. The first groove P1 may be filled with, for example, a non-conductive material.

[0039] The second electrode layers 24 belonging to adjacent photoelectric conversion cells 12 may be electrically separated from each other by a third groove P3. The third groove P3 may be filled with a non-conductive material. The photoelectric conversion layers 26 belonging to adjacent photoelectric conversion cells 12 may be separated from each other by a second groove P2 and a third groove P3.

[0040] The photoelectric conversion element 10 may have an electrical connection portion 34 between adjacent photoelectric conversion cells 12. The electrical connection portion 34 may be made of a conductive material embedded in the second groove P2. As a result, the electrical connection portion 34 electrically connects adjacent photoelectric conversion cells 12 in series. In this embodiment, the electrical connection portion 34 is formed by a portion continuous with the second electrode layer 24. In this case, the electrical connection portion 34 may be made of the same material as the second electrode layer 24. Alternatively, the electrical connection portion 34 may be made of a conductive material different from that of the second electrode layer 24.

[0041] The electrical connection portion 34 extends in the thickness direction of the photoelectric conversion element 10 at the second groove P2, thereby electrically connecting the first electrode layer 22 of one of the adjacent photoelectric conversion cells 12 with the second electrode layer 24 of the other photoelectric conversion cell 12.

[0042] The photoelectric conversion element 10 has a pair of wiring 50 for extracting power. In this embodiment, the pair of wiring 50 is arranged to sandwich a plurality of photoelectric conversion cells 12 in a second direction. In other words, the plurality of photoelectric conversion cells 12 are arranged between one of the pair of wiring 50 and the other of the pair of wiring 50. The pair of wiring 50 may be electrically connected to the first electrode layer 22 of the photoelectric conversion element 10.

[0043] When light is shone on the photoelectric conversion layer 26 of each photoelectric conversion cell 12, an electromotive force is generated, and the first electrode layer 22 and the second electrode layer 24 become the positive and negative electrodes, respectively. Therefore, some of the free electrons generated in a certain photoelectric conversion cell 12 move directly from the second electrode layer 24 through the electrical connection part 34 to the first electrode layer 22 of an adjacent photoelectric conversion cell 12. In this way, the free electrons generated in the photoelectric conversion cell 12 flow through the multiple photoelectric conversion cells 12 in the second direction. The power generated in the photoelectric conversion element 10 is extracted by a pair of wires 50.

[0044] In this embodiment, the first electrode layer 22 may have a covered portion 22a covered by the photoelectric conversion layer 26 and an uncovered portion 22b not covered by the photoelectric conversion layer 26 (see Figures 2 and 3). The covered portion 22a corresponds to at least the portion of the first electrode layer 22 covered by the photoelectric conversion layer 26. The uncovered portion 22b corresponds to the portion of the first electrode layer 22 not covered by the photoelectric conversion layer 26. Note that the uncovered portion 22b of the first electrode layer 22 may be covered by a material other than the photoelectric conversion layer 26.

[0045] The uncoated portion 22b of the first electrode layer 22 may be located in a region different from the first groove P1, the second groove P2, and the third groove P3. While not particularly limited, the uncoated portion 22b of the first electrode layer 22 may be located near the edges of the substrate 20. In the embodiment shown in Figure 2, the uncoated portion 22b of the first electrode layer 22 is located near both ends of the substrate 20 in the second direction.

[0046] Here, all or part of the first buffer layer 27 may be present on the uncoated portion 22b of the first electrode layer 22. In other words, the uncoated portion 22b of the first electrode layer 22 may contain a chalcogenide compound of a transition metal element, specifically a compound containing a transition metal material such as Mo, W, Ti, V, Cr, Nb, or Ta, and a chalcogen element such as O, S, or Se.

[0047] In this embodiment, the uncoated portion 22b of the first electrode layer 22 may have a deficient region 22c on the surface of the coated portion 22a with a relatively small amount of chalcogen elements or no chalcogen elements at all. Figure 4 is a schematic plan view showing an example of a deficient region on the surface of the first electrode layer 22 with little or no chalcogen elements. Figure 5 is a schematic plan view showing another example of a region on the surface of the first electrode layer with little or no chalcogen elements. Figures 4 and 5 are schematic diagrams showing an enlarged portion of the surface of the deficient region 22c of the first electrode layer 22. Specifically, Figures 4 and 5 show schematic plan views of region 3R in Figure 3 as seen from above with the wiring 50 removed.

[0048] The deficient region 22c may be defined as a region containing less chalcogenous elements than the amount of chalcogenous elements on the surface of the coating portion 22a of the first electrode layer 22, or a region that does not contain chalcogenous elements. Here, the chalcogenous elements may be both sulfur and selenium, sulfur, or selenium, and preferably selenium.

[0049] The surface of the coated portion 22a contains chalcogen elements resulting from chalcogenization during the formation of the first buffer layer 27, or more specifically, the photoelectric conversion layer 26. The deficient region 22c corresponds to a region where the amount of chalcogen elements generated during the formation of the first buffer layer 27, or more specifically, the photoelectric conversion layer 26, is reduced, as will be described later.

[0050] The deficient region 22c may be provided in a plurality of separate patterns in the uncoated portion 22b of the first electrode layer 22, as shown in Figures 4 and 5. That is, the uncoated portion 22b of the first electrode layer 22 may have a deficient region 22c and a non-deficient region 22d. In this case, the amount of chalcogen elements on the surface of the deficient region 22c of the first electrode layer 22 is less than the amount of chalcogen elements on the surface of the non-deficient region 22d of the first electrode layer 22. Here, the chalcogen elements may be both sulfur and selenium, sulfur, or selenium, and are preferably selenium.

[0051] In the example shown in Figure 4, the deficient regions 22c are arranged in multiple linear shapes at desired intervals. More specifically, the deficient regions 22c include multiple regions extending linearly in one direction. In the example shown in Figure 5, the deficient regions 22c are arranged in a grid pattern. More specifically, the deficient regions 22c include multiple circular or elliptical regions. Methods for forming the deficient regions 22c and non-deficient regions 22d will be described later. Instead of the embodiments shown in Figures 4 and 5, the entire uncovered portion 22b may be a deficient region 22c, and non-deficient regions 22d may not be provided.

[0052] The pair of wires 50 may be provided on the depleted region 22c of the uncovered portion 22b of the first electrode layer 22. Specifically, the wires 50 are joined to at least the depleted region 22c of the uncovered portion 22b of the first electrode layer 22. However, the wires 50 may also be provided spanning at least the depleted region 22c and the non-depleted region 22d of the uncovered portion 22b of the first electrode layer 22.

[0053] On the surface of the first electrode layer 22, a chalcogen compound is formed by a reaction between the material constituting the first electrode layer 22 and the chalcogen element used when forming the photoelectric conversion layer 26. This chalcogen compound is a compound containing, for example, a transition metal material such as Mo, W, Ti, V, Cr, Nb, or Ta, and a chalcogen element such as O, S, or Se. Such chalcogen compounds often have a layered crystalline structure. If a large amount of such layered chalcogen compounds is present on the surface of the first electrode layer 22, the wiring 50 may become more susceptible to peeling under tensile force, potentially reducing the connection reliability of the wiring 50. In this embodiment, since the wiring 50 is bonded to a deficient region 22c with a small amount of chalcogen element, it is possible to improve the connection reliability of the wiring 50.

[0054] In terms of connection reliability, the peak of the sulfur emission spectrum (peak of distribution in the depth direction) obtained by glow discharge emission analysis on the surface of the deficient region 22c of the first electrode layer 22 may be, for example, 95% or less, preferably 92% or less, and more preferably 90% or less, of the peak of the sulfur emission spectrum obtained by glow discharge emission analysis on the surface of the uncoated portion 22b and / or non-deficient region 22d of the first electrode layer 22.

[0055] In terms of connection reliability, the product of the sulfur emission spectrum and depth obtained by glow discharge emission analysis on the surface of the deficient region 22c of the first electrode layer 22 may be, for example, 95% or less, preferably 92% or less, and more preferably 90% or less, of the product of the sulfur emission spectrum and depth obtained by glow discharge emission analysis on the surface of the uncoated portion 22b and / or the non-deficient region 22d of the first electrode layer 22.

[0056] Similarly, the peak of the selenium emission spectrum (the peak of the distribution in the depth direction) obtained by glow discharge emission analysis on the surface of the deficient region 22c of the first electrode layer 22 may be, for example, 95% or less, preferably 92% or less, more preferably 90% or less, and even more preferably 85% or less of the peak of the selenium emission spectrum obtained by glow discharge emission analysis on the surface of the uncoated portion 22b and / or the non-deficient region 22d of the first electrode layer 22.

[0057] Similarly, the product of the selenium emission spectrum and depth obtained by glow discharge emission analysis on the surface of the depleted region 22c of the first electrode layer 22 may be, for example, 95% or less, preferably 92% or less, more preferably 90% or less, and even more preferably 85% or less, of the product of the selenium emission spectrum and depth obtained by glow discharge emission analysis on the surface of the uncoated portion 22b and / or non-depleted region 22d of the first electrode layer 22.

[0058] In the above embodiment, the wiring 50 is joined to the depleted region 22c of the first electrode layer 22 in order to improve the connection reliability of the wiring 50. However, to improve the connection reliability of the conductor, any conductor may be joined to the depleted region 22c of the first electrode layer 22. Such a conductor may be, for example, an interconnector or a bypass diode.

[0059] In the above embodiment, the photoelectric conversion element 10 has a first groove P1, a second groove P2, and a third groove P3. Alternatively, the photoelectric conversion element 10 may not have the first groove P1, the second groove P2, and the third groove P3.

[0060] [Method for Manufacturing a Photoelectric Conversion Element] Next, a method for manufacturing a photoelectric conversion element according to one embodiment will be described using Figures 6 to 13. Figure 6 is a flowchart showing the method for manufacturing a photoelectric conversion element according to one embodiment. Figure 7 is a schematic cross-sectional view illustrating one step of the method for manufacturing a photoelectric conversion element according to one embodiment. Figure 8 is a schematic diagram illustrating the step following Figure 7. Figure 9 is a schematic diagram illustrating the step following Figure 8. Figure 10 is a schematic diagram illustrating the step following Figure 9. Figure 11 is a schematic diagram illustrating the step following Figure 10. Figure 12 is a schematic diagram illustrating the step following Figure 11. Figure 13 is a schematic diagram illustrating the step following Figure 12.

[0061] The method for manufacturing a photoelectric conversion element according to this embodiment may include the steps of: preparing a substrate S1; forming a first electrode layer S2; forming a first groove P1 S3; forming a photoelectric conversion layer S4; forming a second groove P2 S5; forming a second electrode layer S6; forming a third groove P3 S7; removing a portion of the photoelectric conversion layer and the second electrode layer S8; etching the surface of the first electrode layer S9; and joining conductors S10. Here, the steps of preparing the substrate S1, forming the first groove P1 S3, forming the second groove P2 S5, and forming the third groove P3 S7 are not essential and may be omitted if unnecessary.

[0062] First, a substrate 20 is prepared (step S1). The shape and dimensions of the substrate 20 are appropriately determined according to the size of the photoelectric conversion element 10 to be manufactured. Next, as shown in Figure 7, a first electrode layer is formed on the substrate 20 (step S2). The first electrode layer 22 is formed by depositing the material constituting the first electrode layer 22 onto the surface of the substrate 20, for example, by sputtering.

[0063] The material constituting the first electrode layer 22 may be, for example, at least one transition metal material selected from the group consisting of molybdenum (Mo), tungsten (W), titanium (Ti), vanadium (V), chromium (Cr), niobium (Nb), and tantalum (Ta). Preferably, the first electrode layer 22 may contain molybdenum (Mo).

[0064] The sputtering method may be direct current (DC) sputtering or radio frequency (RF) sputtering. Alternatively, instead of sputtering, the first electrode layer 22 may be formed using methods such as CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition).

[0065] While not particularly limited, the thickness of the first electrode layer 22 may be, for example, 50 nm to 1500 nm, preferably 50 nm to 1200 nm, more preferably 50 nm to 800 nm, and even more preferably 50 nm to 500 nm.

[0066] Next, as shown in Figure 7, a first groove P1 is formed in the first electrode layer 22 (step S3). The first groove P1 can be formed by cutting, for example, mechanical scribing.

[0067] Next, a photoelectric conversion layer 26 having a chalcogen compound is formed on the first electrode layer 22 (step S4). The photoelectric conversion layer 26 having a chalcogen compound may be formed by any method.

[0068] In a specific example, a precursor film 26a is first formed on the first electrode layer 22. The precursor film 26a can be formed, for example, by physical vapor deposition (PVD). Examples of physical vapor deposition (PVD) include sputtering and vapor deposition. Vapor deposition is a method of forming a film using atoms that have been heated into a vapor phase by heating a deposition source.

[0069] When forming a CIS-based photoelectric conversion layer 26, the precursor film 26a is formed by depositing at least a group I element and a group III element. For example, the precursor film 26a may be formed as a laminate of a film containing a group III element and a film containing a group I element. The group I element can be selected from, for example, Ag, Cu, Au, etc. The group III element can be selected from, for example, indium, gallium, aluminum, etc.

[0070] Furthermore, the precursor film 26a may additionally contain selenium, sulfur, and / or tellurium as group VI elements.

[0071] As an example, the precursor film 26a may be formed as a laminate of a film containing a group I element and a group III element, and a film containing a group III element. Also, as shown in Figure 8, the precursor film 26a may include a first film 26b containing a group I element and a group III element, a second film 26c containing a group I element and a group III element, and a third film 26d containing a group III element.

[0072] On the other hand, when forming a CZTS-based photoelectric conversion layer 26, the precursor layer 26a is formed by depositing at least Cu, Zn, and Sn elements, or by depositing at least Cu, Zn, Sn, Se, and S elements. The precursor layer 26a may be formed as a thin film of, for example, Cu-Zn-Sn or Cu-Zn-Sn-Se-S.

[0073] Next, the material constituting the precursor film 26a is chalcogenized. By chalcogenizing the precursor film 26a, the photoelectric conversion layer 26 can be formed. The chalcogenization may include at least one, preferably both, of selenization and sulfidation.

[0074] When forming a CIS-based photoelectric conversion layer 26, the chalcogenization treatment of the precursor film 26a involves heating the precursor film 26a, which contains at least group I and group III elements, in an atmosphere containing group VI elements. This chalcogenizes the precursor film 26a, forming a photoelectric conversion layer 26 containing chalcogen compounds (see Figure 9).

[0075] Specifically, in the chalcogenization process, for example, selenization is first performed by a gas-phase selenization method. Selenization is carried out by heating the precursor layer in an atmosphere of a selenium source gas (e.g., hydrogen selenide or selenium vapor) containing selenium as a group VI element source. Although not particularly limited, selenization is preferably carried out in a heating furnace at a temperature in the range of, for example, 250°C to 650°C, preferably 350°C to 650°C, and more preferably 450°C to 650°C.

[0076] As a result, the precursor film is converted into a compound (photoelectric conversion layer 26) containing a group I element, a group III element, and selenium. Note that the compound (photoelectric conversion layer 26) containing a group I element, a group III element, and selenium may be formed by methods other than the gas-phase selenization method. For example, such a compound can also be formed by solid-phase selenization, vapor deposition, ink coating, electrodeposition, etc.

[0077] Next, a compound containing a Group I element, a Group III element, and selenium is sulfurized. The sulfurization is carried out by heating the selenized precursor film and the glass substrate 20 in an atmosphere of a sulfur-containing sulfur source gas (e.g., hydrogen sulfide or sulfur vapor). As a result, the photoelectric conversion layer 26 is converted into a semiconductor compound containing a Group I element, a Group III element, and selenium and sulfur as Group VI elements. The sulfur source gas plays a role in substituting selenium with sulfur in crystals composed of Group I elements, Group III elements, and selenium, such as chalcopyrite crystals, on the surface of the photoelectric conversion layer 26.

[0078] The sulfidation is preferably carried out, for example, in a heating furnace at a temperature within the range of 450°C to 650°C.

[0079] Through the chalcogenization described above, the precursor film 26a is converted into the photoelectric conversion layer 26. In addition, along with the chalcogenization, a first buffer layer 27 is formed between the first electrode layer 22 and the photoelectric conversion layer 26. This buffer layer 27 contains a compound having transition metal materials such as Mo, W, Ti, V, Cr, Nb, and Ta that constitute the first electrode layer 22, and chalcogen elements such as O, S, and Se. In other words, chalcogen elements are present on the surface of the first electrode layer 22.

[0080] On the other hand, when forming a CZTS-based photoelectric conversion layer 26, the chalcogenization treatment of the precursor layer 26a involves sulfidating and selenizing the precursor layer 26a containing Cu, Zn, and Sn, and the glass substrate 20 in a hydrogen sulfide atmosphere and a hydrogen selenide atmosphere at a temperature within the range of 450°C to 650°C. This process results in Cu ２ ZnSn(S,Se) ４ A CZTS-based photoelectric conversion layer 26 having the above properties can be formed. Furthermore, the above sulfidation and selenization process forms a first buffer layer 27 between the first electrode layer 22 and the photoelectric conversion layer 26.

[0081] In the above embodiment, both selenization and sulfidation are performed when the precursor film 26a is converted into the photoelectric conversion layer 26. However, the precursor film can be converted into the photoelectric conversion layer 26 by any chalcogenization treatment.

[0082] In the above embodiment, the step of forming a photoelectric conversion layer 26 having a chalcogen compound (step S4) includes forming a precursor film and then sulfiding and / or selenizing the precursor film.

[0083] Alternatively, in the step of forming the photoelectric conversion layer 26 having a chalcogen compound, all elements constituting the photoelectric conversion layer 26 (including the chalcogen element) may be formed by a film deposition method such as sputtering. That is, the photoelectric conversion layer 26 may be formed without sulfidation and / or selenization.

[0084] For example, when forming a CIS-based photoelectric conversion layer 26, at least group I, group III, and group VI elements should be formed by a film deposition method such as sputtering. The types of group I, group III, and group VI elements are as described above. Specifically, the group VI elements include at least sulfur or selenium, or both sulfur and selenium. Also, when forming a CZTS-based photoelectric conversion layer 26, for example, elements such as Cu, Zn, Sn, Se, and S should be formed by a film deposition method such as sputtering.

[0085] After the formation of the photoelectric conversion layer 26, a second groove P2 is formed in the first electrode layer 22 and the photoelectric conversion layer 26, as shown in Figure 10 (step S5). The second groove P2 can be formed by cutting, for example, mechanical scribing.

[0086] Next, a second electrode layer 24 is formed on the photoelectric conversion layer 26 (step S6). The second electrode layer 24 is formed by depositing the material constituting the second electrode layer 24 onto the photoelectric conversion layer 26 using methods such as sputtering, CVD, or ALD (see Figure 11).

[0087] Next, as shown in Figure 12, a third groove P3 is formed in the second electrode layer 24 and the photoelectric conversion layer 26 (step S7). The third groove P3 can be formed by cutting, for example, mechanical scribing.

[0088] Furthermore, as shown in Figure 12, separate from the formation of the third groove P3, at least a portion of the photoelectric conversion layer 26 is removed (step S8). Preferably, step S8, in which a portion of the photoelectric conversion layer is removed, includes removing a portion of the second electrode layer 24 along with a portion of the photoelectric conversion layer 26. The portion from which the photoelectric conversion layer 26 and the second electrode layer 24 have been removed corresponds to the uncovered portion 22b that is not covered by the photoelectric conversion layer 26. The removal of the photoelectric conversion layer 26 and the second electrode layer 24 can be achieved by cutting, for example, by mechanical scribing.

[0089] Step S8 may be performed after step S7, simultaneously with step S7, or before step S7.

[0090] Next, as shown in Figure 13, the surface of the first electrode layer 22 is etched in a region where at least the photoelectric conversion layer 26, specifically the second electrode layer 24 and a portion of the photoelectric conversion layer 26, has been removed (step S9). Specifically, the etching is performed on the portion of the first electrode layer 22 from which the photoelectric conversion layer 26 and the second electrode layer 24 have been removed. Etching can be performed by, for example, laser irradiation, dry etching such as plasma treatment, wet etching, mechanical polishing, blasting, or ultrasonic vibration. Wet etching can be performed using an etching solution such as hydrochloric acid, nitric acid, sodium hydroxide solution, or ammonia solution. Examples of blasting include dry ice blasting and sandblasting. In the example shown in Figure 13, a laser 90 is irradiated as etching on the portion of the first electrode layer 22 from which the photoelectric conversion layer 26 and the second electrode layer 24 have been removed.

[0091] During the chalcogenization process described above, chalcogen elements are present on the surface of the first electrode layer 22. By etching the surface of at least the region where a portion of the photoelectric conversion layer 26 has been removed, the amount of chalcogen elements present on the surface of the first electrode layer 22 is reduced. In other words, in step S9, the amount of chalcogen elements on the surface of the first electrode layer 22 is reduced by etching. The etched region is a region where the amount of chalcogen elements on the surface of the first electrode layer 22 is reduced compared to the unetched region. Therefore, the etched region corresponds to the deficient region 22c of the first electrode layer 22 described above.

[0092] The etching conditions are not particularly limited, as long as the chalcogen elements on the surface of the first electrode layer 22 can be removed at least partially. For example, the wavelength and power of the laser 90 are not particularly limited, as long as the chalcogen elements on the surface of the first electrode layer 22 can be removed at least partially.

[0093] Here, it is preferable to reduce the amount of sulfur or selenium on the surface of the first electrode layer 22 by etching. More preferably, the amount of selenium on the surface of the first electrode layer 22 is reduced by etching.

[0094] The pattern of the area to be etched is not particularly limited. The pattern of the area to be etched may be, for example, the same as the pattern of the depleted area 22c described above. Therefore, when laser irradiation is performed as etching, the laser 90 may be irradiated toward the first electrode layer 22 in multiple linear directions at desired intervals, similar to the pattern of the depleted area 22c in Figure 4.

[0095] Alternatively, when laser irradiation is used for etching, the laser 90 may be spot-irradiated in a grid pattern toward the first electrode layer 22, as shown in Figure 5.

[0096] If etching is performed only on a portion of the region where the second electrode layer 24 and part of the photoelectric conversion layer 26 are removed, it is possible to suppress the occurrence of large cracks in the material constituting the first electrode layer 22.

[0097] In the embodiment described above, etching is not performed on the entire region where the second electrode layer 24 and a portion of the photoelectric conversion layer 26 have been removed, but only on a portion of the region. Alternatively, etching may be performed on the entire portion where the photoelectric conversion layer 26 and the second electrode layer 24 have been removed.

[0098] Preferably, the amount of sulfur or selenium on the surface of the first electrode layer 22 is reduced by 5 at% or more by etching. More preferably, the amount of sulfur or selenium on the surface of the first electrode layer 22 is reduced by 8 at% or more by etching. Even more preferably, the amount of sulfur or selenium on the surface of the first electrode layer 22 is reduced by 10 at% or more by etching. Alternatively, the amount of sulfur or selenium on the surface of the first electrode layer 22 may be reduced by 15 at% or more by etching. The amount of chalcogen element removal can be controlled by the size of the etching area and the etching conditions. For example, when laser irradiation is used for etching, the amount of chalcogen element removal can be controlled by the size of the laser irradiation area and the laser power, etc. Reducing the amount of sulfur or selenium by 15 at% or more is more preferable from the viewpoint of the tensile strength of the conductor, which will be described later.

[0099] Next, a conductor is joined to the etched portion of the first electrode layer 22 (step S10). The conductor may be, for example, wiring 50, an interconnector, or a bypass diode. When the wiring 50, which is the conductor, is joined to the etched portion of the first electrode layer 22, a photoelectric conversion element 10 as shown in Figure 3 is obtained.

[0100] The etched region on the first electrode layer 22, i.e., the deficient region 22c, corresponds to a region with a low amount of chalcogen compound. This chalcogen compound is a compound containing, for example, a transition metal material such as Mo, W, Ti, V, Cr, Nb, or Ta, and a chalcogen element such as O, S, or Se. Such chalcogen compounds often have a layered crystalline structure. If a large amount of such chalcogen compound is present on the surface of the first electrode layer 22, the wiring 50 may become more susceptible to peeling under tensile force, potentially reducing the connection reliability of the wiring 50. In this embodiment, since the conductor is joined to the deficient region 22c with a low amount of chalcogen element, it is possible to improve the connection reliability of the wiring 50.

[0101] [Experimental Example 1] Next, Experimental Example 1 will be described. The photoelectric conversion element according to Experimental Example 1 includes a substrate 20, a first electrode layer 22 on the substrate 20, a first buffer layer 27 on the first electrode layer 22, a photoelectric conversion layer 26 on the first buffer layer 27, and a second electrode layer 24 on the photoelectric conversion layer 26.

[0102] In Experimental Example 1, the first electrode layer 22 is mainly composed of Mo. The first buffer layer is mainly composed of Mo, Se, and S. The photoelectric conversion layer 26 is a CIS-based photoelectric conversion layer, mainly composed of Cu, In, Ga, Se, and S. The second electrode layer 24 is made of indium tin oxide, mainly composed of In, Sn, and O.

[0103] In Experimental Example 1, a portion of the second electrode layer 24 and the photoelectric conversion layer 26 of the photoelectric conversion element was removed by mechanical scribing. Next, a laser was irradiated onto the portion where the second electrode layer 24 and the photoelectric conversion layer 26 had been removed, towards the first electrode layer 22. The laser irradiation formed the aforementioned deficient region 22c on the first electrode layer 22.

[0104] In Experimental Example 1, laser irradiation was performed using a laser marker (MD-X2020A, wavelength 1064 nm). The laser irradiation pattern, i.e., the pattern of the deficient region 22c, is shown in Figure 4. Specifically, the laser irradiated the first electrode layer 22 in multiple linear patterns. The spacing between the multiple linear lasers was 0.06 mm.

[0105] Next, the elemental emission spectra of each element were measured using glow discharge-OES (GD-OES) in the laser-irradiated area (deficient region 22c) and the area not irradiated with the laser. The GD-OES method allows for elemental analysis in the depth direction of the sample.

[0106] Figure 14 is a graph showing the results of the elemental emission spectrum obtained by glow discharge emission analysis in the first electrode layer 22 that was not irradiated with a laser in Experimental Example 1. Therefore, Figure 14 is considered to show experimental results corresponding to the elemental ratio in the coated portion 22a of the first electrode layer 22 that is covered by the photoelectric conversion layer 26, or in the non-depleted region 22d of the uncoated portion 22b of the first electrode layer 22.

[0107] Figure 15 is a graph showing the results of the elemental emission spectrum obtained by glow discharge emission analysis in the first electrode layer 22 irradiated with a laser in Experimental Example 1. Therefore, Figure 15 is considered to show experimental results corresponding to the elemental ratio in the deficient region 22c of the uncoated portion 22b of the first electrode layer 22.

[0108] In Figures 14 and 15, the horizontal axis represents the etching time in glow discharge emission analysis and corresponds to the depth from the surface of the uncoated portion 22b. The etching rate was 7–8 nm / sec. "0 seconds" on the horizontal axis represents the position of the surface of the uncoated portion 22b formed by removing a part of the photoelectric conversion layer 26 by mechanical scribing. The area around 50–60 seconds on the horizontal axis is thought to correspond to the time (depth) to reach the substrate 20, given the significant decrease in molybdenum content. In Figures 14 and 15, the vertical axis shows the intensity of the emission spectrum measured by the GD-OES method. Figures 14 and 15 show the emission spectra of selenium, sulfur, and molybdenum.

[0109] Comparing Figures 14 and 15, the emission spectrum of molybdenum (first electrode layer 22) does not change much between the areas not irradiated with the laser and the areas irradiated with the laser. On the other hand, the emission spectra of selenium and sulfur are significantly reduced on the surface of the first electrode layer 22 irradiated with the laser.

[0110] Specifically, the peak of the selenium emission spectrum on the surface of the first electrode layer 22 irradiated with the laser is approximately 61% of the peak of the selenium emission spectrum on the surface of the first electrode layer 22 that is not irradiated with the laser. The peak of the sulfur emission spectrum on the surface of the first electrode layer 22 irradiated with the laser is approximately 59% of the peak of the sulfur emission spectrum on the surface of the first electrode layer 22 that is not irradiated with the laser.

[0111] [Experimental Example 2] Next, Experimental Example 2 will be described. The photoelectric conversion element according to Experimental Example 2 includes a substrate 20, a first electrode layer 22 on the substrate 20, a first buffer layer 27 on the first electrode layer 22, a photoelectric conversion layer 26 on the first buffer layer 27, and a second electrode layer 24 on the photoelectric conversion layer 26.

[0112] In Experimental Example 2, the first electrode layer 22 is mainly composed of Mo. The first buffer layer is mainly composed of Mo, Se, and S. The photoelectric conversion layer 26 is a CIS-based photoelectric conversion layer, mainly composed of Cu, In, Ga, Se, and S. The second electrode layer 24 is made of indium tin oxide, mainly composed of In, Sn, and O.

[0113] In Experimental Example 2, a portion of the second electrode layer 24 and the photoelectric conversion layer 26 of the photoelectric conversion element was removed by mechanical scribing. Next, a laser was irradiated onto the portion where the second electrode layer 24 and the photoelectric conversion layer 26 had been removed, towards the first electrode layer 22. The laser irradiation formed the aforementioned deficient region 22c on the first electrode layer 22.

[0114] In Experimental Example 2, laser irradiation was performed using a fiber laser processing machine (ML-7320CL, wavelength 1064 nm). The laser irradiation pattern, i.e., the pattern of the deficient region 22c, is shown in Figure 5. That is, the laser irradiated the first electrode layer 22 in a grid pattern. The grid spacing of the grid-like laser pattern was 0.04 mm.

[0115] Next, the content ratio (emission spectrum) of each element was measured in the laser-irradiated area (deficient region 22c) and the unirradiated area using glow discharge-OES (GD-OES) method. The GD-OES method allows for elemental analysis in the depth direction of the sample.

[0116] Figure 16 is a graph showing the results of the elemental emission spectrum obtained by glow discharge emission analysis in the first electrode layer 22 that was not irradiated with a laser in Experimental Example 2. Therefore, Figure 16 is considered to show experimental results corresponding to the elemental ratio in the coated portion 22a of the first electrode layer 22 that is covered by the photoelectric conversion layer 26, or in the non-depleted region 22d of the uncoated portion 22b of the first electrode layer 22.

[0117] Figure 17 is a graph showing the results of the elemental emission spectrum obtained by glow discharge emission analysis in the first electrode layer 22 irradiated with a laser in Experimental Example 2. Therefore, Figure 17 is considered to show experimental results corresponding to the elemental ratio in the deficient region 22c of the uncoated portion 22b of the first electrode layer 22.

[0118] In Figures 16 and 17, the horizontal axis, as in Figures 14 and 15, represents the etching time in glow discharge emission analysis and corresponds to the depth from the surface of the uncoated portion 22b. The etching rate was 7-8 nm / sec. "0 seconds" on the horizontal axis represents the position of the surface of the uncoated portion 22b formed by removing a part of the photoelectric conversion layer 26 by mechanical scribing. The area around 50-60 seconds on the horizontal axis is thought to correspond to the time (depth) to reach the substrate 20, given the significant decrease in molybdenum content. In Figures 16 and 17, the vertical axis, as in Figures 14 and 15, shows the emission spectra of each element measured by the GD-OES method.

[0119] Comparing Figures 16 and 17, the emission spectrum of molybdenum (first electrode layer 22) does not change much between the area not irradiated with the laser and the area irradiated with the laser. On the other hand, it can be seen that the emission spectrum of selenium, at least, decreases on the surface of the first electrode layer 22 irradiated with the laser.

[0120] Specifically, the peak of the selenium emission spectrum obtained by glow discharge emission analysis on the surface of the first electrode layer 22 irradiated with a laser is approximately 89% of the peak of the selenium emission spectrum obtained by glow discharge emission analysis on the surface of the first electrode layer 22 that was not irradiated with a laser.

[0121] In Experimental Examples 1 and 2, the amount of chalcogen elements (both selenium and sulfur, or at least selenium) on the surface of the first electrode layer 22 irradiated with a laser (deficient region 22c) was lower than the amount of chalcogen elements on the surface of the first electrode layer 22 that was not irradiated with a laser.

[0122] Therefore, in the case of a photoelectric conversion element manufactured by the above-described method for manufacturing a photoelectric conversion element, the deficient region 22c of the first electrode layer 22 is a region containing less chalcogenous elements than the amount of chalcogenous elements on the surface of the covering portion 22a of the first electrode layer 22, and / or a region containing less chalcogenous elements than the amount of chalcogenous elements on the surface of the non-deficient region 22d of the first electrode layer 22. Here, the chalcogenous elements may be both sulfur and selenium, sulfur, or selenium, and are preferably selenium.

[0123] Next, we will describe the experimental results regarding the connection reliability of conductors to the photoelectric conversion elements in Experimental Example 1 and Experimental Example 2. In Experimental Example 1 and Experimental Example 2 described above, the ends of conductors (interconnectors) made of Cu were joined to the region on the first electrode layer 22 of the photoelectric conversion element irradiated with a laser, i.e., the deficient region 22c, using a conductive adhesive (Daiso: NB8302).

[0124] In addition, a different photoelectric conversion element was prepared as a comparative example. The photoelectric conversion element in the comparative example is the same as the photoelectric conversion elements in Experimental Example 1 and Experimental Example 2, except that the laser was not irradiated onto the portion where the second electrode layer 24 and the photoelectric conversion layer 26 were removed. In the comparative example, the end of a Cu conductor (interconnector) was bonded to the first electrode layer 22, which was exposed after removing the second electrode layer 24 and the photoelectric conversion layer 26, using a conductive adhesive (Daiso: NB8302).

[0125] A tensile strength test (45° tensile test) was performed on the photoelectric conversion elements in Experimental Example 1, Experimental Example 2, and the Comparative Example. Specifically, the unjointed end of the conductor was clamped with a jig, and the conductor was pulled using an autograph device. The tensile force (tensile strength) at the point when the conductor joint separated was then measured.

[0126] For each of Experimental Example 1 and Experimental Example 2, the same tensile test was repeated four times, and the average tensile strength was calculated. Similarly, for the Comparative Example, the same tensile test was repeated eight times, and the average tensile strength was calculated.

[0127] The average tensile strength obtained from the photoelectric conversion element in Experimental Example 1 was 1.33 times the average tensile strength obtained from the photoelectric conversion element in the Comparative Example. Furthermore, the average tensile strength obtained from the photoelectric conversion element in Experimental Example 2 was 1.28 times the average tensile strength obtained from the photoelectric conversion element in the Comparative Example.

[0128] From the above results, it can be seen that when a conductor is joined to a region on the first electrode layer 22 that has been irradiated with a laser, i.e., a deficient region 22c in which the amount of chalcogen elements is relatively small or does not contain chalcogen elements, the connection reliability of the conductor is improved.

[0129] [Photoelectric Conversion Module] Next, a photoelectric conversion module according to one embodiment will be described with reference to Figure 18. Figure 18 is a schematic plan view of the photoelectric conversion module according to one embodiment.

[0130] The photoelectric conversion module 100 may include one or more photoelectric conversion elements 10. Figure 18 shows a photoelectric conversion module 100 that includes multiple photoelectric conversion elements 10. One or more photoelectric conversion elements 10 may be sealed, for example, with a sealing material. The configuration of each photoelectric conversion element 10 is as described in the above embodiments.

[0131] 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 grid pattern. In this case, the plurality of photoelectric conversion elements 10 may be electrically connected to each other in series and / or in parallel.

[0132] Adjacent photoelectric conversion elements 10 may be electrically connected to each other by a connector. In this case, the connector may extend across adjacent photoelectric conversion elements 10.

[0133] [Artificial Satellite and Paddle for Artificial Satellite] Next, an artificial satellite equipped with a photoelectric conversion module and a paddle for an artificial satellite will be described. Figure 19 is a schematic perspective view of an artificial satellite equipped with a photoelectric conversion module. The artificial satellite 900 may have a base 910 and a paddle 920. The base 910 may be equipped with equipment not shown that is necessary for controlling the artificial satellite 900. An antenna 940 may be attached to the base 910.

[0134] The paddle 920 may be equipped with the aforementioned photoelectric conversion module 100. The paddle 920 equipped with the photoelectric conversion module 100 can be used as a power source to operate various devices provided on the base 910. In this way, the photoelectric conversion module 100 can be applied to paddles for artificial satellites.

[0135] The paddle 920 may have a connecting portion 922 and a hinge portion 924. The connecting portion 922 corresponds to the part that connects the paddle 920 to the base portion 910.

[0136] The hinge portion 924 extends along one direction, allowing the paddle 920 to be folded around the hinge portion 924 as an axis of rotation. Each paddle 920 may have at least one, preferably more than one, hinge portion 924. This allows the paddle 920 equipped with the photoelectric conversion module 100 to be foldable into a small size. At the time of launch of the satellite 900, the paddle 920 may be in a folded state. The paddle 920 should be unfolded when generating electricity by receiving sunlight.

[0137] Instead of the structure shown in Figure 19, the paddle 920 may have a cylindrical shape formed by winding. This allows the paddle 920 to take on a substantially flat unfolded state due to the rotation of the wound portion. During the launch of the satellite 900, the paddle 920 may maintain a generally cylindrical shape. When generating electricity by receiving sunlight, the paddle 920 should unfold to a substantially flat state.

[0138] As described above, the scope of the present invention has been disclosed through embodiments, but the descriptions and drawings that constitute part of this disclosure should not be understood as limiting the present invention. Various alternative embodiments, examples, and operational techniques will become apparent to those skilled in the art from this disclosure. Therefore, the technical scope of the present invention is defined solely by the inventive features relating to the claims that are reasonable from the above description.

[0139] This application claims priority under Japanese Patent Application No. 2025-026184, filed on 20 February 2025, the entire contents of said patent application are incorporated herein by reference.

Claims

1. A method for manufacturing a photoelectric element, comprising the steps of: forming a photoelectric conversion layer having a chalcogen compound on a first electrode layer; removing a portion of the photoelectric conversion layer; and etching the surface of the first electrode layer in at least the region where a portion of the photoelectric conversion layer has been removed.

2. A method for manufacturing a photoelectric element according to claim 1, comprising the step of joining a conductor to a portion of the surface of the first electrode layer that has been etched.

3. The method for manufacturing a photoelectric element according to claim 1 or 2, wherein the photoelectric conversion layer comprises at least sulfur or selenium, or both sulfur and selenium.

4. A method for manufacturing a photoelectric element according to any one of claims 1 to 3, comprising reducing the amount of chalcogen elements on the surface of the first electrode layer by etching.

5. A method for manufacturing a photoelectric element according to claim 3, comprising reducing the amount of sulfur or selenium on the surface of the first electrode layer by etching.

6. The method for manufacturing a photoelectric element according to claim 5, comprising reducing the amount of sulfur or selenium on the surface of the first electrode layer by 5 at% or more by etching.

7. The method for manufacturing a photoelectric element according to any one of claims 1 to 6, wherein the etching is performed by irradiation with a laser.

8. The method for manufacturing a photoelectric conversion element according to any one of claims 1 to 6, wherein the etching is performed by plasma treatment.

9. The method for manufacturing a photoelectric element according to any one of claims 1 to 6, wherein the etching is performed by wet etching.

10. The method for manufacturing a photoelectric element according to any one of claims 1 to 6, wherein the etching is performed by mechanical polishing.

11. The method for manufacturing a photoelectric element according to any one of claims 1 to 6, wherein the etching is performed by blasting.

12. The method for manufacturing a photoelectric element according to any one of claims 1 to 6, wherein the etching is performed by ultrasonic vibration.

13. The method for manufacturing a photoelectric element according to any one of claims 1 to 12, wherein the first electrode layer comprises at least one selected from the group consisting of molybdenum, tungsten, titanium, vanadium, chromium, niobium, and tantalum.

14. A method for manufacturing a photoelectric conversion element according to any one of claims 1 to 13, comprising the step of forming a second electrode layer on the photoelectric conversion layer, wherein the step of removing a portion of the photoelectric conversion layer includes removing a portion of the second electrode layer together with the portion of the photoelectric conversion layer.

15. A photoelectric conversion element comprising a first electrode layer and a photoelectric conversion layer on the first electrode layer, wherein the photoelectric conversion layer contains a chalcogen compound, and the first electrode layer has a coated portion covered by the photoelectric conversion layer and an uncoated portion not covered by the photoelectric conversion layer, wherein the uncoated portion of the first electrode layer contains less chalcogen element than the amount of chalcogen element on the surface of the coated portion of the first electrode layer, or has a deficient region that does not contain chalcogen element.

16. The photoelectric conversion element according to claim 15, further comprising a conductor joined to the deficient region of the first electrode layer.

17. The photoelectric element according to claim 15 or 16, wherein the chalcogen element is sulfur or selenium, or both sulfur and selenium.

18. The photoelectric conversion element according to claim 17, wherein the peak of the emission spectrum of the chalcogen element obtained by glow discharge emission analysis on the surface of the deficient region of the first electrode layer is 95% or less of the peak of the emission spectrum of the chalcogen element obtained by glow discharge emission analysis on the surface of the coated portion of the first electrode layer.

19. The photoelectric conversion element according to any one of claims 15 to 18, wherein the deficient region of the first electrode layer is provided in a plurality of linear shapes at desired intervals.

20. The photoelectric conversion element according to any one of claims 15 to 18, wherein the deficient region of the first electrode layer is arranged in a grid pattern.

21. The photoelectric conversion element according to any one of claims 15 to 20, wherein the first electrode layer comprises at least one selected from the group consisting of molybdenum, tungsten, titanium, vanadium, chromium, niobium, and tantalum.

22. A photoelectric conversion module comprising a photoelectric conversion element according to any one of claims 15 to 21.

23. A paddle comprising a photoelectric conversion element according to any one of claims 15 to 21.

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