Photoelectric conversion element, photoelectric conversion module, and photoelectric conversion system

Abstract

To provide a photoelectric conversion element, a photoelectric conversion module, and a photoelectric conversion system, in which the characteristic deterioration due to a doping material of a hole transport layer does not easily occur.SOLUTION: A photoelectric conversion element 10 includes a first electrode 11 and a second electrode 15, a photoelectric conversion layer 13 provided between the first electrode 11 and the second electrode 15, and a hole transport layer 14 provided between the first electrode 11 and the photoelectric conversion layer 13 or between the second electrode 15 and the photoelectric conversion layer 13. The hole transport layer 14 includes a hole transport molecular material and Cs atoms.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a photoelectric conversion device, a photoelectric conversion module, and a photoelectric conversion system using a perovskite compound.

Background Art

[0002] Generally, a hole transport layer of a photoelectric conversion device contains Lithium Bis(trifluoromethanesulfonyl)imid (hereinafter, LiTFSI) and 4-tert-Butylpyridine (hereinafter, tBP) as doping materials (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, solar cells (perovskite solar cells) including a photoelectric conversion layer using a perovskite compound have attracted attention. In a photoelectric conversion device of a perovskite solar cell, when LiTFSI is used as a doping material for the hole transport layer, Li in the hole transport layer easily diffuses into the photoelectric conversion layer (perovskite layer) due to voltage application or temperature rise caused by device operation, which is likely to cause characteristic degradation. Alternatively, since LiTFSI has hygroscopicity, moisture in the air may penetrate into the photoelectric conversion layer through LiTFSI, which may also cause characteristic degradation. In addition, tBP may invade the perovskite layer, which is likely to cause characteristic degradation. Note that the same problems also occur in a light-emitting device including a light-emitting layer using a perovskite compound.

[0005] This disclosure has been made in view of the above-mentioned problems, and aims to provide a photoelectric conversion element, a photoelectric conversion module, and a photoelectric conversion system that are less susceptible to performance degradation due to doping materials in the hole transport layer. [Means for solving the problem]

[0006] To solve the aforementioned problems, the following photoelectric conversion element, photoelectric conversion module, and photoelectric conversion system are provided.

[0007] (1) Photoelectric conversion element The photoelectric conversion element of the present disclosure comprises a first electrode and a second electrode, a photoelectric conversion layer provided between the first electrode and the second electrode, and a hole transport layer provided between the first electrode and the photoelectric conversion layer, or between the second electrode and the photoelectric conversion layer, wherein the hole transport layer contains a hole-transporting molecular material and Cs atoms.

[0008] (2) Photoelectric conversion module The photoelectric conversion module of the present disclosure is characterized in that it has at least one photoelectric conversion element, wherein the photoelectric conversion element is the photoelectric conversion element described above.

[0009] (3) Photoelectric conversion system The photoelectric conversion system disclosed herein is characterized by comprising the photoelectric conversion module and control circuit described above. [Effects of the Invention]

[0010] The photoelectric conversion element, photoelectric conversion module, and photoelectric conversion system disclosed herein can suppress the degradation of properties caused by doping materials in the hole transport layer. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic cross-sectional view of the photoelectric conversion element related to this disclosure. [Figure 2] This is a schematic cross-sectional view showing a modified photoelectric conversion element. [Figure 3]This is a plan view of the photoelectric conversion module related to this disclosure. [Figure 4] Figure 3 is a cross-sectional view of the photoelectric conversion module shown. [Figure 5] Figure 3 is a circuit diagram of the photoelectric conversion module. [Figure 6] This is a schematic diagram of the photoelectric conversion system related to this disclosure. [Figure 7] This is a schematic cross-sectional view of the light-emitting element relating to this disclosure. [Modes for carrying out the invention]

[0012] [First Embodiment] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Figure 1 shows one embodiment of the present disclosure and is a schematic cross-sectional view of the photoelectric conversion element 10.

[0013] As shown in Figure 1, the photoelectric conversion element 10 is formed on a substrate 20 and has a first electrode 11, an electron transport layer 12, a photoelectric conversion layer 13, a hole transport layer 14, and a second electrode 15. The first electrode 11, electron transport layer 12, photoelectric conversion layer 13, hole transport layer 14, and second electrode 15 are stacked in this order from the side closest to the substrate 20. Note that the stacking order does not necessarily have to be in this order (forward structure type), and the order of the electron transport layer 12 and the hole transport layer 14 may be reversed (reverse structure type). That is, the hole transport side may be on the bottom and the electron transport side on the top. In this disclosure, the electron transport layer is described as a forward structure type, but in the case of a reverse structure type, it can be replaced with a hole transport layer as long as it does not contradict the original structure.

[0014] Furthermore, the positions of the electron transport layer 12 and the hole transport layer 14 may be swapped. Also, the electron transport layer 12 is not essential in the photoelectric conversion element 10 and can be omitted.

[0015] The substrate 20 is a substrate on which the photoelectric conversion element 10 is provided. In the present disclosure, the substrate 20 will be described without being included in the photoelectric conversion element 10, but it may be included in the photoelectric conversion element 10. The substrate 20 is also called a base body or a base material, etc., and is the same as or includes them. The substrate 20 may be hard and highly rigid, or may be flexible or low in rigidity. The substrate 20 is preferably light transmissive. For example, resin films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, or glass can be used. Note that light transmissive means transmitting light, but does not exclude those that reflect or absorb even a little light. It is only necessary that it is provided on the light receiving surface side or the light emitting surface side of the element and can appropriately transmit light, and it can be considered synonymous with being provided on the light receiving surface side or the light emitting surface side of the element. Therefore, it can be considered light transmissive as long as it is provided at least on the light receiving surface side of the photoelectric conversion element 10 (or the light emitting surface side of the light emitting element 10A described later).

[0016] The first electrode 11 is a member having conductivity. As the first electrode 11, it is preferable to use a light transmissive conductive material. For example, transparent conductive materials such as aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), gallium-doped zinc oxide (GZO), tin oxide (SnO2), fluorine-doped tin oxide (FTO), indium tin oxide (ITO), etc. can be used. The first electrode 11 may be formed by a known method such as sputtering or vapor deposition, and the film thickness may be, for example, 30 nm or more and 1000 nm or less.

[0017] The electron transport layer 12 is a layer capable of transporting electrons. Note that as long as the photoelectric conversion element 10 (or the light emitting element 10A described later) is functioning, it is obvious that the layer disposed on the negative electrode side of these elements has an electron transport function, and it can be regarded as an electron transport layer. The negative electrode side can be rephrased as the electron transport side.

[0018] As the electron transport layer 12, tin oxide, titanium oxide, zinc oxide, indium oxide, and a mixture or compound of two or more of these can be used. The electron transport layer 12 may be formed by a known method such as a spin coating method or a sputtering method, and the film thickness may be, for example, 10 nm or more and 200 nm or less. Further, the electron transport layer 12 may be able to inhibit (hole blocking) the transport of holes. Further, the electron transport layer 12 may be accompanied by a separate hole blocking layer. Further, there may be no electron transport layer 12 and instead a hole blocking layer may be provided. Note that the electron transport layer 12 and the hole blocking layer may indicate the same thing. Similar to the description of the electron transport layer 12, the hole blocking layer does not need to be confirmed as long as the device functions.

[0019] The photoelectric conversion layer 13 is a layer that can absorb light and generate electrons and holes. Further, when used as a light-emitting device, it is a layer that can recombine electrons and holes to emit light. The photoelectric conversion layer 13 includes a light absorption portion that can absorb light containing a perovskite compound or the like and generate electrons and holes. Further, as a light-emitting device, the photoelectric conversion layer includes a light-emitting portion that can recombine electrons and holes containing a perovskite compound or the like to emit light. The photoelectric conversion layer 13 may also include an electron transport layer, a hole transport layer, or an insulating layer. The electron transport layer, hole transport layer, or insulating layer included in the photoelectric conversion layer 13 is preferably a porous material.

[0020] As the photoelectric conversion layer 13, for example, a perovskite-type compound containing a halogen can be used. Usually, for a photoelectric conversion layer 13 having a perovskite compound used in a solar cell, Cs, FA (formamidinium, CH(NH2)2 + ), MA (methylammonium, CH3NH3 +It includes one or more elements selected from the group consisting of ), one or more elements selected from the group consisting of Pb and Sn, and one or more elements selected from the group consisting of I, Br, and Cl. However, in the description of this embodiment, including the above-mentioned FA and MA, it is not a matter of whether each constituent element is ionized or not. The photoelectric conversion layer 13 may be formed by known film deposition methods such as spin coating, die coating, or inkjet, and the film thickness may be, for example, 100 nm or more and 1000 nm or less. Note that unless otherwise specified, the term "layer" does not define thickness or width, and includes patterned or island-shaped layers or layers with different thicknesses. Preferably, a layer has a substantially constant thickness.

[0021] Perovskite compounds are General formula: ABX3...(1) It is composed of compounds represented by the formula (1). However, the composition ratio of each is preferably 1:1:3, but it does not necessarily have to be 1:1:3, the content of each element may be raised or lowered as appropriate, and each constituent element does not have to be of only one type, and as long as the photoelectric conversion element 10 has a photoelectric conversion function, it has the degree of freedom of composition as described above. In general formula (1), A is an organic molecule (including an organic group or an organic cation, as is the case in this disclosure) or an inorganic atom (including an inorganic cation, as is the case in this disclosure) or a combination thereof, B is a metal atom (including a metal cation, as is the case in this disclosure), and X is a halogen atom (including a halogen anion, as is the case in this disclosure). In general formula (1), the three Xs may be the same or different from each other. The perovskite compound is able to absorb light and convert it into electricity by being included in the photoelectric conversion layer 13, and this should also be taken into consideration, that is, it is sufficient to know that it is a perovskite compound if it contains, for example, an organic molecule, a metal atom and a halogen atom. Furthermore, to confirm that a compound is a perovskite compound, it is sufficient that elements corresponding to A, B, and X are detected, insofar as the photoelectric conversion element 10 has a photoelectric conversion function. For example, molecules containing carbon, nitrogen, and hydrogen are suitable as organic molecules; therefore, it is sufficient that carbon, nitrogen, hydrogen, metallic elements, and halogen elements are detected. Alternatively, to confirm that a compound is a perovskite compound, it is sufficient that it contains A, B, and X; for example, it is sufficient that it contains inorganic atoms, metallic atoms, and halogen atoms. Furthermore, to confirm that a compound is a perovskite compound, it is sufficient that elements corresponding to A, B, and X are detected, insofar as the photoelectric conversion element 10 has a photoelectric conversion function. For example, cesium or rubidium are suitable as inorganic atoms; therefore, it is sufficient that cesium or rubidium, metallic elements (preferably lead and tin), and halogens are detected. Also, to confirm that a compound is a perovskite compound, it is not necessary to confirm that it has a crystalline structure, as this is a natural consequence of the photoelectric conversion element 10 having a photoelectric conversion function. The photoelectric conversion layer 13 may contain compounds other than perovskite compounds.

[0022] Furthermore, the light-absorbing layer may contain organic-inorganic hybrid compounds. An organic-inorganic hybrid compound means a compound that contains both inorganic and organic elements. Perovskite compounds are included in organic-inorganic hybrid compounds. Organic typically refers to materials composed of multiple carbon elements. However, carbon materials such as graphite, graphene, carbon nanowires, carbon nanofibers, carbon nanotubes, and carbon or carbon black that function as electrodes are not specifically considered organic. In other words, organic refers to materials in which multiple carbon elements are one of the constituent elements, excluding the aforementioned carbon materials such as graphite. Inorganic means materials that are not organic.

[0023] Examples of organic molecules represented by A in general formula (1) include alkylamines, alkylammonium compounds, and nitrogen-containing heterocyclic compounds. In perovskite compound (1), the organic molecule represented by A may be only one type of organic molecule, or it may be two or more types of organic molecules.

[0024] Examples of alkylamines include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, and ethylbutylamine.

[0025] Alkylammonium compounds are ionized compounds of the alkylamines mentioned above. Examples of alkylammonium compounds include methylammonium (CH3NH3), ethylammonium, propylammonium, butylammonium, pentylammonium, hexylammonium, dimethylammonium, diethylammonium, dipropylammonium, dibutylammonium, dipentylammonium, dihexylammonium, trimethylammonium, triethylammonium, tripropylammonium, tributylammonium, tripentylammonium, trihexylammonium, ethylmethylammonium, methylpropylammonium, butylmethylammonium, methylpentylammonium, hexylmethylammonium, ethylpropylammonium, and ethylbutylammonium.

[0026] Examples of nitrogen-containing heterocyclic compounds include imidazole, azole, pyrrole, aziridine, azirine, azetidine, azeto, azole, imidazoline, and carbazole. Nitrogen-containing heterocyclic compounds may also be ionized. Phenethylammonium is preferred as an ionized nitrogen-containing heterocyclic compound.

[0027] In general formula (1), the organic molecule represented by A is preferably methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, methylammonium, ethylammonium, propylammonium, butylammonium, pentylammonium, hexylammonium, or phenethylammonium, more preferably methylamine, ethylamine, propylamine, methylammonium, ethylammonium, or propylammonium, and even more preferably methylammonium.

[0028] In general formula (1), examples of metal atoms represented by B include lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium. In perovskite compounds, the metal atom represented by B may be only one type of metal atom, or it may be two or more types of metal atoms. From the viewpoint of improving the light absorption and charge generation characteristics of the perovskite compound, lead atoms or tin atoms are preferred as the metal atom represented by B. From the viewpoint of reducing lead, tin atoms are preferred.

[0029] Furthermore, examples of halogen atoms represented by X in general formula (1) include fluorine, chlorine, bromine, and iodine atoms, and examples of chalcogen atoms include oxygen, sulfur, selenium, and tellurium atoms. In a perovskite compound, the halogen atom or chalcogen atom represented by X may be one or two or more. From the viewpoint of enabling the perovskite compound to utilize light in a wide wavelength range, iodine is preferred as the halogen atom represented by X. More specifically, it is preferable that at least one of the three Xs represents an iodine atom, and it is more preferable that all three Xs represent iodine atoms.

[0030] In the light-absorbing layer, the perovskite compound preferably has A selected from the group consisting of cesium, rubidium, methylammonium, and formamidinium as A in general formula (1). Furthermore, in general formula (1), B preferably has one selected from the group consisting of lead and tin. Furthermore, in general formula (1), C preferably has one selected from the group consisting of iodine, bromine, and chlorine.

[0031] The hole transport layer 14 is a layer capable of transporting holes. The material of the hole transport layer 14 will be described later. It is self-evident that, as long as the photoelectric conversion element 10 (or light-emitting element 10A) is functioning, the layer located on the positive electrode side of the element will have a hole transport function and can be considered a hole transport layer. The hole transport layer 14 may also inhibit electron transport (electron blocking). The hole transport layer 14 may also be accompanied by a separate electron blocking layer. Alternatively, the hole transport layer 14 may be absent, and instead, an electron blocking layer may be present. The hole transport layer 14 and the electron blocking layer can be shown to be common to each other. Similar to the explanation of the hole transport layer 14, the electron blocking layer is also located on the positive electrode side of the element and does not require verification as long as the element is functioning. The positive electrode side may be referred to as the hole transport side. The hole transport layer 14 can be deposited using known film deposition methods such as spin coating, die coating, or inkjet, and the film thickness can be, for example, 40 nm to 600 nm.

[0032] The second electrode 15 preferably contains a metal or alloy containing one or more of Au, Ag, Cu, or Al. Alternatively, a transparent conductive material such as ITO, ZnO, FTO, SnO2, or IZO may be used as the second electrode 15. The second electrode 15 can be deposited using a known film deposition method such as vacuum deposition or sputtering, and the film thickness should be, for example, 50 nm to 300 nm.

[0033] The hole transport layer 14 in the photoelectric conversion element 10 of this disclosure will be described in detail below.

[0034] The hole transport layer 14 is formed by adding a doping material to a hole-transporting molecular material. Examples of hole-transporting molecular materials that can be used include spiro-OMeTAD(2,2',7,7'-Tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene), PTAA (Poly[bis(4-phenyl)(2,4,6-triMethylphenyl)amine]), P3HT (Poly(3-hexylthiophene-2,5-diyl)), poly-TPD (Poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]), and PVK (polyvinyl carbazole). The hole transport layer 14 can be formed by dissolving the doping material described later in a solvent with the hole-transporting molecular material to create a precursor solution, and then forming the film using a known film deposition method.

[0035] In the photoelectric conversion element 10 of this disclosure, the hole transport layer 14 does not need to use LiTFSI and tBP as doping materials. Instead, the hole transport layer 14 contains Cs atoms as doping materials. In this disclosure, Cs atoms refer to Cs ions. In the hole transport layer 14, the molar ratio of Cs atoms to hole-transporting molecules is preferably 0.01 or more and 1.00 or less. Furthermore, it is most preferable that the doping materials do not contain any LiTFSI and tBP, but it is not required that they be contained at all, and their inclusion is permitted as appropriate.

[0036] Because Cs has a larger atomic and ionic radius than Li, it does not easily diffuse into the perovskite layer (i.e., the photoelectric conversion layer 13). As a result, the hole transport layer 14 using Cs atoms or Cs ions as doping material does not easily diffuse the doping material into the photoelectric conversion layer 13, thereby suppressing the degradation of the characteristics of the photoelectric conversion element 10.

[0037] Furthermore, the hole transport layer 14 may contain TFSI molecules or ions. In this case, CsTFSI can be used as a doping material in the hole transport layer 14, making it easier to obtain an effective doping effect.

[0038] Furthermore, the hole transport layer 14 preferably contains a crown ether (crown ether molecule). Dibenzo-21-crown-7 can be suitably used as the crown ether; that is, the hole transport layer 14 preferably contains a Dibenzo-21-crown-7 molecule. In the hole transport layer 14, the molar ratio of crown ether molecules to Cs atoms is preferably 0.9 or more and 1.1 or less.

[0039] For example, when CsTFSI and Dibenzo-21-crown-7 are used as doping materials in the hole transport layer 14, Cs atoms or Cs ions are incorporated into Dibenzo-21-crown-7, forming a complex as shown in the following formula. In addition, CsTFSI that has lost its Cs atoms exists in the hole transport layer 14 as TFSI molecules or ions, contributing to an increase in the hole density in the hole transport layer 14.

[0040] [ka]

[0041] In this case, the incorporation of Cs atoms or Cs ions into the crown ether more effectively suppresses the diffusion of Cs into layers other than the hole transport layer 14 (e.g., the photoelectric conversion layer 13). Furthermore, the crown ether prevents Cs atoms or Cs ions from directly contacting the hole transporter molecule, thereby improving the hole transport capacity of the hole transporter molecule.

[0042] [Second Embodiment] In this embodiment, preferred examples of the photoelectric conversion layer 13 will be described. In this embodiment, the configuration can be the same as in the first embodiment, except as described below.

[0043] In this embodiment, the photoelectric conversion layer 13 contains Cs. Thus, by including Cs in the photoelectric conversion layer 13, Cs is present in both the photoelectric conversion layer 13 and the hole transport layer 14 of the photoelectric conversion element 10. In this case, the Cs in the photoelectric conversion layer 13 acts to suppress Cs diffusion from the hole transport layer 14 to the photoelectric conversion layer 13. As a result, compositional changes in the photoelectric conversion layer 13 are suppressed, and the degradation of the characteristics of the photoelectric conversion element 10 can be suppressed more effectively.

[0044] Furthermore, in order to suppress Cs diffusion from the hole transport layer 14 to the photoelectric conversion layer 13 through the above action, it is preferable that the Cs atom density is high in the region of the photoelectric conversion layer 13 that is close to the hole transport layer 14. For this reason, in the photoelectric conversion layer 13, the Cs atom density in the region closer to the hole transport layer 14 may be higher than the Cs atom density in the region further away from the hole transport layer 14. For example, as shown in Figure 2, when the hole transport layer 14 is divided into two regions 14a and 14b in the center in the film thickness direction, the Cs atom density (average Cs atom density) in the region 14a closer to the hole transport layer 14 may be higher than the Cs atom density (average Cs atom density) in the region 14b further away from the hole transport layer 14. Alternatively, in a comparison between a point in region 14a and a point in region 14b, the Cs atom number density in region 14a may be greater than the Cs atom number density in region 14b (for example, in the cross-section of the device, a point in region 14a and a point in region 14b can be measured and compared using Auger electron spectroscopy (energy-dispersive X-ray analysis is also possible)). In this case, it is preferable that the Cs atom number density in region 14a is 1.2 times or more than the Cs atom number density in region 14b, and more preferably 10 times or more.

[0045] [Third Embodiment] In this embodiment, the photoelectric conversion module and photoelectric conversion system of the present disclosure will be described. Figure 3 is a plan view of the photoelectric conversion module 100 according to the present disclosure. Figure 4 is a cross-sectional view of the photoelectric conversion module 100 (cross-sectional view IV-IV in Figure 3).

[0046] The photoelectric conversion module 100 comprises a plurality of photoelectric conversion elements 10 as described in the first or second embodiment, and these plurality of photoelectric conversion elements 10 are connected in series. However, the number of photoelectric conversion elements 10 in the photoelectric conversion module of this disclosure is not particularly limited, and it is sufficient to have at least one photoelectric conversion element 10. Furthermore, when multiple photoelectric conversion elements 10 are provided, the element connection is not limited to a series connection, but may also be in parallel, or a combination of series and parallel connections may be used.

[0047] As shown in Figure 3, the photoelectric conversion module 100 is patterned with several cuts, and has regions P1, P2, and P3 corresponding to these cuts. In Figure 3, the second electrode 15 and the first electrode 11 (or electron transport layer 12) of the photoelectric conversion element 10 are present on the surface. For patterning such as processing in regions P1 to P3, for example, wet etching, dry etching, laser scribing, or mechanical scribing can be used.

[0048] As shown in Figure 4, the cut in region P1 is formed by etching away the first electrode 11, separating the first electrodes 11 of two adjacent photoelectric conversion elements 10 (for example, photoelectric conversion elements 10a and 10b in Figure 4).

[0049] The notch in region P2 is formed by etching away the electron transport layer 12, the photoelectric conversion layer 13, and the hole transport layer 14, and is provided to electrically connect two adjacent photoelectric conversion elements 10 (for example, photoelectric conversion elements 10a and 10b in Figure 8). That is, in region P2, the material for the second electrode 15 is filled into the formed notch, thereby connecting the second electrode 15 of one photoelectric conversion element 10 (for example, photoelectric conversion element 10a) to the first electrode 11 of the other photoelectric conversion element 10 (for example, photoelectric conversion element 10b).

[0050] The cut in region P3 is formed by patterning the photoelectric conversion layer 13, the hole transport layer 14, and the second electrode 15, and is provided to separate the second electrode 15 of two adjacent photoelectric conversion elements 10 (for example, photoelectric conversion elements 10a and 10b in Figure 4). In region P3 of Figure 4, the formed cut etches away up to the photoelectric conversion layer 13, and the electron transport layer 12 is exposed on the surface of region P3. However, in region P3, it is sufficient that at least the second electrode 15 is removed, and it is more preferable that the hole transport layer 14 is also removed, but the photoelectric conversion layer 15 does not necessarily have to be removed. In other words, a part of the photoelectric conversion layer 13 may remain. In this case, the photoelectric conversion layer 13 is exposed on the surface of region P3. Alternatively, at least a part of the hole transport layer 14 may be exposed without removing at least a part of it. Alternatively, the electron transport layer 12 may also be removed to expose at least a portion of the first electrode 11.

[0051] In the photoelectric conversion module 100, the region between region P3 and region P1, excluding region P2, is the region where the photoelectric conversion elements 10 are formed. The region between region P3 and region P1, including region P2, is the connection region for electrically connecting two adjacent photoelectric conversion elements 10.

[0052] Thus, the photoelectric conversion module 100 is configured to isolate the photoelectric conversion elements 10 using regions P1 and P3, and to electrically connect two adjacent photoelectric conversion elements 10 using region P2. As a result, the photoelectric conversion module 100 includes multiple photoelectric conversion elements 10 connected in series, as shown in the circuit diagram of Figure 5.

[0053] Figure 6 is a schematic diagram of the photoelectric conversion system 1000 according to this disclosure. As shown in Figure 6, the photoelectric conversion system 1000 comprises the photoelectric conversion module 100 described above, a power conditioner 101, a distribution board 102, a power meter 103, a storage battery 104, and electrical equipment 105. The photoelectric conversion system 1000 illustrated in Figure 10 is provided with one each of the photoelectric conversion module 100, a power conditioner 101 as an example of a control circuit, a distribution board 102, a power meter 103, a storage battery 104, and electrical equipment 105, but multiple units of each may be provided. In other words, the photoelectric conversion system 1000 comprises the photoelectric conversion module 100 and a control circuit. The control circuit can be anything that can control the current or voltage output from the photoelectric conversion module 100.

[0054] The power conditioner 101 controls the current and voltage so that the power output from the photoelectric conversion module 100 is optimal, and also monitors the output power of the photoelectric conversion module 100 and the charge level of the battery 104 to perform the desired power distribution and output power to the battery 104 and the distribution board 102. At this time, it outputs DC power to the battery 104 and AC power to the distribution board 102. In other words, the power conditioner 101 has the function of converting DC power to AC power.

[0055] The distribution board 102 receives AC power from the power conditioner 101 and supplies it to the electrical equipment 105 and the power meter 103 in a desired distribution while monitoring the output power of the power conditioner 101 and the power consumption of the electrical equipment 105.

[0056] The power meter 103 measures the power supplied from the distribution board 102 and supplies it to the commercial power grid.

[0057] The electrical equipment 105 may be connected to the power conditioner 101 instead of the distribution board 102. In this case, the power conditioner 101 monitors the output power of the photoelectric conversion module 100, the charge level of the battery 104, and the power consumption of the electrical equipment 105, and performs the desired power distribution, supplying AC power to the distribution board 102, DC power to the battery 104, and AC power to the electrical equipment 105. If the electrical equipment 105 is for DC power, DC power may be supplied.

[0058] [Fourth Embodiment] In the first and second embodiments described above, the photoelectric conversion element 10 according to the disclosure was explained. In this embodiment, the case in which the photoelectric conversion element 10 according to the disclosure functions as a light-emitting element 10A will be explained. Figure 7 is a schematic cross-sectional view of the light-emitting element 10A.

[0059] As shown in Figure 7, the light-emitting element 10A has a configuration almost identical to that of the photoelectric conversion element 10, but instead of the photoelectric conversion layer 13 of the photoelectric conversion element 10, it has a light-emitting layer 13A. The first electrode 11, electron transport layer 12, hole transport layer 14, and second electrode 15 of the light-emitting element 10A can have the same configuration as those of the photoelectric conversion element 10. The substrate 20 can also be used in the same way as that of the photoelectric conversion element 10. The light-emitting element 10A is a device that causes the light-emitting layer 13A to emit light by passing an electric current through the first electrode 11 and the second electrode 15 to the light-emitting layer 13A.

[0060] In the light-emitting element 10A, a perovskite semiconductor containing, for example, a halogen is used in the light-emitting layer 13A. That is, in the photoelectric conversion element 10, the photoelectric conversion layer 13 is a perovskite layer, but in the light-emitting element 10A, the light-emitting layer 13A is a perovskite layer. The perovskite semiconductor used as the light-emitting layer can be the same material and formation method as in the photoelectric conversion element 10, but is not limited to this.

[0061] Even in light-emitting elements having a perovskite layer, using LiTFSI or tBP as the doping material for the hole transport layer presents the same problem of performance degradation in the perovskite layer as in the case of photoelectric conversion elements. Therefore, in the light-emitting element 10A of this embodiment, performance degradation of the light-emitting layer 13A can be suppressed by using the hole transport layer 14 described in the first and second embodiments.

[0062] Furthermore, the photoelectric conversion module 100 and photoelectric conversion system 1000 described in the third embodiment can also be modified to a photoelectric conversion module and photoelectric conversion system in which the direction of current flow is reversed and the photoelectric conversion element 10 functions as a light-emitting element 10A.

[0063] The embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. Therefore, the technical scope of this disclosure is not to be interpreted solely by the embodiments described above, but rather by the claims. [Explanation of Symbols]

[0064] 10 Photoelectric conversion element 10A Light-emitting element 20 circuit boards 11 1st electrode 12 Electron transport layer 13 Photoelectric conversion layer 13A Light-emitting layer 14 Hole transport layer 15 2nd electrode 100 Photoelectric Conversion Modules 101 Power Conditioner (Control Circuit) 1000 Photoelectric Conversion Systems

Claims

1. First electrode and second electrode, A photoelectric conversion layer is provided between the first electrode and the second electrode, The device comprises a hole transport layer provided between the first electrode and the photoelectric conversion layer, or between the second electrode and the photoelectric conversion layer, The hole transport layer comprises a hole transport molecule and a Cs atom. The photoelectric conversion layer comprises a perovskite compound and contains Cs atoms. A photoelectric conversion element characterized in that the number density of Cs atoms in the photoelectric conversion layer is greater in the region close to the hole transport layer than in the region far from the hole transport layer.

2. First electrode and second electrode, A photoelectric conversion layer is provided between the first electrode and the second electrode, The device comprises a hole transport layer provided between the first electrode and the photoelectric conversion layer, or between the second electrode and the photoelectric conversion layer, The hole transport layer comprises a hole transport molecule, a Cs atom, and a crown ether molecule. The photoelectric conversion layer comprises a perovskite compound, The photoelectric conversion element is characterized in that the crown ether molecule is a Dibenzo-21-crown-7 molecule.

3. A photoelectric conversion element according to Claim 1, The hole transport layer does not include at least one of tBP and LiTFSI. A photoelectric conversion element characterized in that the molar ratio of the Cs atoms to the hole-transporting molecules in the hole transport layer is 0.01 or more and 1.00 or less.

4. A photoelectric conversion element according to Claim 2, The hole transport layer does not include at least one of tBP and LiTFSI. A photoelectric conversion element characterized in that the molar ratio of the Cs atoms to the hole-transporting molecules in the hole transport layer is 0.01 or more and 1.00 or less.

5. A photoelectric conversion element according to any one of claims 1 to 4, The photoelectric conversion element is characterized in that the photoelectric conversion layer includes one or more selected from the group consisting of Pb and Sn, and one or more selected from the group consisting of I, Br, and Cl.

6. A photoelectric conversion element according to claim 1 or 2, A photoelectric conversion element characterized in that the molar ratio of Cs atoms to hole-transporting molecules in the hole transport layer is 0.01 or more and 1.00 or less.

7. A photoelectric conversion element according to any one of claims 1 to 4, The photoelectric conversion element is characterized in that the hole transporting molecule is one of spiro-OMeTAD, PTAA, P3HT, poly-TPD, and PVK.

8. A photoelectric conversion element according to claim 1 or 3, The photoelectric conversion element is characterized in that the hole transport layer further contains crown ether molecules.

9. A photoelectric conversion element according to claim 8, The photoelectric conversion element is characterized in that the crown ether molecule is a Dibenzo-21-crown-7 molecule.

10. A photoelectric conversion element according to claim 2 or 4, A photoelectric conversion element characterized in that the molar ratio of the crown ether molecules to the Cs atoms in the hole transport layer is 0.9 or more and 1.1 or less.

11. A photoelectric conversion element according to claim 8, A photoelectric conversion element characterized in that the molar ratio of the crown ether molecules to the Cs atoms in the hole transport layer is 0.9 or more and 1.1 or less.

12. A photoelectric conversion element according to claim 2 or 4, The photoelectric conversion element is characterized in that the photoelectric conversion layer contains Cs.

13. A photoelectric conversion element according to claim 12, A photoelectric conversion element characterized in that the number density of Cs atoms in the photoelectric conversion layer is greater in the region close to the hole transport layer than in the region far from the hole transport layer.

14. A photoelectric conversion element according to claim 1 or 3, A photoelectric conversion element characterized in that, in the photoelectric conversion layer, the number density of Cs atoms in the region close to the hole transport layer is 1.2 times or more than the number density of Cs atoms in the region far from the hole transport layer.

15. A photoelectric conversion element according to claim 12, A photoelectric conversion element characterized in that, in the photoelectric conversion layer, the number density of Cs atoms in the region close to the hole transport layer is 1.2 times or more than the number density of Cs atoms in the region far from the hole transport layer.

16. A photoelectric conversion element according to claim 1 or 3, A photoelectric conversion element characterized in that, in the photoelectric conversion layer, the number density of Cs atoms in the region close to the hole transport layer is 10 times or more than the number density of Cs atoms in the region far from the hole transport layer.

17. A photoelectric conversion element according to claim 12, A photoelectric conversion element characterized in that, in the photoelectric conversion layer, the number density of Cs atoms in the region close to the hole transport layer is 10 times or more than the number density of Cs atoms in the region far from the hole transport layer.

18. A photoelectric conversion module having at least one photoelectric conversion element, wherein the photoelectric conversion element is the photoelectric conversion element described in any one of claims 1 to 4.

19. A photoelectric conversion system characterized by comprising the photoelectric conversion module and control circuit described in claim 18.

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