Photoelectric conversion element
Patent Information
- Application Number
- CN202610212525.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-02-21
- Filing Date
- 2026-02-13
- Publication Date
- 2026-08-21
Smart Images
Figure CN122622474A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a photoelectric conversion element. Background Technology
[0002] Patent document 1 describes a perovskite solar cell comprising a transparent conductive support, an electron blocking layer, a perovskite layer, an electron transport layer, a hole blocking layer, and a back electrode, wherein both the electron blocking layer and the hole blocking layer comprise inorganic materials.
[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-547766 Summary of the Invention
[0004] However, existing solar cells have the following problem: due to the reflection of sunlight at the interface of the photoelectric conversion layer, the amount of sunlight incident into the interior of the photoelectric conversion layer is reduced, resulting in a decrease in photoelectric conversion efficiency.
[0005] In other words, existing solar cells and the photoelectric conversion elements used in solar cells suffer from the problem of not being able to sufficiently improve photoelectric conversion efficiency. Patent Document 1 does not disclose a technology that can solve the problem described above.
[0006] This disclosure was made to solve such a problem, and its purpose is to provide a photoelectric conversion element that can improve photoelectric conversion efficiency.
[0007] The photoelectric conversion element disclosed herein comprises: a first electrode layer serving as a transparent electrode, a second electrode layer, and a photoelectric conversion band located between the first electrode layer and the second electrode layer. The photoelectric conversion element of this disclosure further comprises a reflection suppression band between the photoelectric conversion band and the first electrode layer, comprising inorganic nanoparticles that are at least one of an insulator and a semiconductor, wherein the thickness of the reflection suppression band is 0.26 times or less the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
[0008] Based on this configuration, the inorganic nanoparticles contained in the reflection suppression band scatter the light incident on the photoelectric conversion element, thereby suppressing the reflection of the incident light. As a result, the photoelectric conversion element of this disclosure can improve the photoelectric conversion efficiency.
[0009] In the photoelectric conversion element disclosed herein, the thickness of the reflection suppression band can be 0.05 to 0.20 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
[0010] In the photoelectric conversion element disclosed herein, the thickness of the reflection suppression band can be 0.08 to 0.13 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
[0011] In the photoelectric conversion element disclosed herein, the inorganic nanoparticles may contain zirconium oxide as the main component.
[0012] In the photoelectric conversion element disclosed herein, the inorganic nanoparticles contain silicon dioxide as the main component, and the thickness of the reflection suppression band can be 0.08 to 0.12 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
[0013] According to this disclosure, it is possible to provide a photoelectric conversion element that can improve photoelectric conversion efficiency.
[0014] The above and other features, characteristics and advantages of this disclosure will be more fully understood through the following detailed description and accompanying drawings. Attached Figure Description
[0015] Figure 1 This is a cross-sectional view showing the configuration of the photoelectric conversion element according to the first embodiment.
[0016] Figure 2 This is a flowchart illustrating a method for manufacturing a photoelectric conversion element according to the first embodiment.
[0017] Figure 3 This is a cross-sectional view used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment.
[0018] Figure 4 This is a cross-sectional view used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment.
[0019] Figure 5 This is a flowchart showing the configuration of the photoelectric conversion element according to the first embodiment.
[0020] Figure 6 This is a cross-sectional view used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment.
[0021] Figure 7 This is a cross-sectional view used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment.
[0022] Figure 8 This is a cross-sectional view used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment.
[0023] Figure 9 This is a graph showing the estimated short-circuit current density lost due to light reflection.
[0024] Figure 10 This is a graph showing the estimated short-circuit current density lost due to light reflection.
[0025] Figure 11This is a graph showing the estimated short-circuit current density lost due to light reflection.
[0026] Figure 12 This is a graph showing the estimated short-circuit current density lost due to light reflection. Detailed Implementation
[0027] <First Embodiment>
[0028] (Composition of photoelectric conversion element)
[0029] Hereinafter, the first embodiment of this disclosure will be described in detail with reference to the accompanying drawings. First, the configuration of the photoelectric conversion element of this embodiment will be described in detail.
[0030] Figure 1 This is a cross-sectional view showing the configuration of the photoelectric conversion element according to the first embodiment. More specifically, it is a schematic cross-sectional view of the photoelectric conversion element of the first embodiment when cut along a plane perpendicular to the main surface. It should be noted that, of course, Figure 1 The right-handed xyz rectangular coordinate system shown in the other figures is a coordinate system used to facilitate the explanation of the positional relationships of the constituent elements and is common to all figures.
[0031] In addition, for convenience, the positive z-axis side is sometimes referred to as the upper side and the negative z-axis side as the lower side in this specification.
[0032] The photoelectric conversion element 1 in this embodiment is a device that converts light incident from the positive or negative z-axis side into electrical energy. The photoelectric conversion element 1 is typically used as a solar cell. Figure 1 As shown, the photoelectric conversion element 1 includes a substrate 11, a first electrode layer 12, a first carrier transport layer 13, a photoelectric conversion layer 14, a second carrier transport layer 15, and a second electrode layer 16.
[0033] It should be noted that the photoelectric conversion element 1 of this embodiment can be used as the upper battery unit of a series-connected solar cell.
[0034] As will be described in detail later, the photoelectric conversion element 1 of this embodiment can suppress the reflection of incident light. Therefore, by using the photoelectric conversion element 1 of this embodiment as the photoelectric conversion element located at the outermost surface when viewed from the light incident side in a series solar cell, it is also possible to improve the power generation of photoelectric conversion elements located at a deeper level when viewed from the light incident side.
[0035] That is, the photoelectric conversion element 1 of this embodiment has a special effect by being used as the upper battery unit of a series-type solar cell.
[0036] In addition, the photoelectric conversion element 1 of this embodiment can also be used in solar cells, for example, in windows of vehicles or buildings.
[0037] As described above, the photoelectric conversion element 1 of this embodiment can suppress the reflection of incident light. Therefore, the photoelectric conversion element 1 of this embodiment, through the use of solar cells in window glass of vehicles or buildings, can introduce more light into the interior of vehicles or buildings.
[0038] That is, the photoelectric conversion element 1 of this embodiment achieves a special effect by being applied to the solar cell in the window glass.
[0039] (Structure of substrate 11)
[0040] The substrate 11 is a plate-shaped or film-shaped component, and its main surface on the positive side of the z-axis abuts against the first electrode layer 12.
[0041] The substrate 11 can be made of any material, as long as it is a material that transmits light within at least the wavelength range absorbed by the photoelectric conversion element 1. Specific examples of materials for the substrate 11 include glass and resin.
[0042] From the viewpoint of manufacturing efficiency, substrate 11 is preferably a film-like component made of resin material, while from the viewpoint of durability, substrate 11 is preferably a plate-like component made of glass material. The composition of substrate 11 can be appropriately selected according to the intended use of photoelectric conversion element 1, etc.
[0043] (The structure of the first electrode layer 12)
[0044] The first electrode layer 12 is a conductive and transparent layer. That is, the first electrode layer 12 is implemented in the form of a transparent electrode layer.
[0045] The first electrode layer 12 abuts against the substrate 11 on its main surface on the negative z-axis side and against the first carrier transport layer 13 on its main surface on the positive z-axis side. That is, in this embodiment, the first electrode layer 12 is located between the substrate 11 and the first carrier transport layer 13.
[0046] The first electrode layer 12 receives charge carriers generated in the photoelectric conversion layer 14 through the first charge carrier transport layer and outputs them to the outside. However, the charge carriers referred to here are holes or conduction electrons.
[0047] When the first carrier transport layer 13, described later, is a hole transport layer, the first electrode layer 12 receives the holes generated in the photoelectric conversion layer 14 as carriers and outputs them to the outside.
[0048] In addition, when the first carrier transport layer 13 is an electron transport layer, the first electrode layer 12 receives the conduction electrons generated in the photoelectric conversion layer 14 as carriers and outputs them to the outside.
[0049] Materials used for the first electrode layer 12 include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide with impurities (ZnO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), graphene, and metal nanowires.
[0050] (The structure of the first carrier transport layer 13 and the second carrier transport layer 15)
[0051] In the photoelectric conversion element 1 of this embodiment, the first carrier transport layer 13 is a hole transport layer (HTL), and the second carrier transport layer 15 is an electron transport layer (ETL). That is, the photoelectric conversion element 1 in this embodiment is an inverted photoelectric conversion element.
[0052] However, the photoelectric conversion element of this disclosure can also be a cis-type structure. That is, the photoelectric conversion element of this disclosure can have an electron transport layer (ETL) as the first carrier transport layer and a hole transport layer (HTL) as the second carrier transport layer.
[0053] (The structure of the first carrier transport layer 13)
[0054] As described above, the first carrier transport layer 13 in this embodiment is a hole transport layer (HTL). The first carrier transport layer 13 abuts against the first electrode layer 12 on its main surface on the negative z-axis and abuts against the photoelectric conversion layer 14 on its main surface on the positive z-axis. That is, the first carrier transport layer 13 in this embodiment is located between the first electrode layer 12 and the photoelectric conversion layer 14.
[0055] The first carrier transport layer 13 transports holes generated in the photoelectric conversion layer 14 to the first electrode layer 12. In other words, holes generated in the photoelectric conversion layer 14 migrate to the first electrode layer 12 via the first carrier transport layer 13.
[0056] Both inorganic hole transport materials and organic hole transport materials can be used as the material for the first carrier transport layer 13.
[0057] Examples of inorganic hole transport materials include CuI, CuInSe2, CuS, CuSCN, GaP, NiO, FeO, Bi2O3, MoO3, and Cr2O.
[0058] Examples of organic hole transport materials include, for example, polythiophene derivatives, fluorene derivatives, carbazole derivatives, triphenylamine derivatives, diphenylamine derivatives, polysilane derivatives, and polyaniline derivatives.
[0059] Specific examples of polythiophene derivatives include poly-3-hexylthiophene (P3HT) and polyvinyldioxythiophene (PEDOT). Specific examples of fluorene derivatives include 2,2',7,7'-tetratetra(N,N-di-p-methoxyphenylamino)-9,9'-spirodifluorene (Spiro-OMeTAD). Specific examples of carbazole derivatives include polyvinylcarbazole. Specific examples of triphenylamine derivatives include poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA).
[0060] It should be noted that the first carrier transport layer 13 in this embodiment can be constructed in the form of a monolayer. In this case, the first carrier transport layer 13 can be a monolayer formed by combining a compound represented by the following formula (1) with the first electrode layer 12.
[0061] Ar-(L-Z) n …Formula (1)
[0062] in,
[0063] Ar can be an n-valent aryl group that can contain a heteroaromatic ring.
[0064] L represents a single bond or a divalent functional group.
[0065] Z is a monovalent functional group with binding capacity.
[0066] n is a natural number.
[0067] When n is 2 or more, (L-Z) can be different.
[0068] Ar can be an n-valent aryl group containing a heteroaromatic ring. From the viewpoint of improving hole transport properties, it is preferable that the heteroaromatic ring contains a nitrogen atom. When Ar contains a heteroaromatic ring, the bonding site can be a carbon atom, a heteroatom, or both. Specific examples of Ar include carbazole rings and triazatruxene rings.
[0069] L is a single bond or a divalent functional group. However, when L is a single bond, the compound represented by chemical formula (1) has a structure in which Ar and Z are directly bonded. Specific examples of L include, for example, divalent alkylenes such as 1,1-methylene and 1,2-ethylene, and divalent alkoxys such as diethoxyethylene.
[0070] Z is a monovalent functional group with binding capacity, which can bind to the transparent electrode layer and can accept or transfer charges between the functional group and the transparent electrode layer. Specific examples of Z include phosphonic acid group, carboxyl group, sulfonyl group, borate group, trihalosilyl group, and trialkoxysilyl group.
[0071] n is a natural number, preferably a natural number between 1 and 4. When n is 2 or more, multiple (L-Z) can be the same or different.
[0072] Specific examples of compounds represented by the above formula (1) include, for example, 3PATAT-C3 (phosphonic acid functionalized triazatruxene).
[0073] (Composition of photoelectric conversion layer 14)
[0074] The photoelectric conversion layer 14 excites electrons by absorbing sunlight incident from the negative z-axis, generating holes and conducting electrons.
[0075] Holes generated in the photoelectric conversion layer 14 are transported to the first electrode layer 12 via the first carrier transport layer 13, and conduction electrons generated in the photoelectric conversion layer 14 are transported to the second electrode layer 16 via the second carrier transport layer 15.
[0076] The photoelectric conversion layer 14 of this embodiment may contain a perovskite compound as the main component, and may also contain appropriate additives. It should be noted that the perovskite compound referred to here is a group of compounds having a perovskite-type crystal structure.
[0077] As a compound that can be used as the main component of the photoelectric conversion layer 14, for example, a perovskite compound represented by the compositional formula of the following formula (2) can be cited.
[0078] AMX3…Form (2)
[0079] in,
[0080] A is a monovalent cation.
[0081] M is a divalent cation.
[0082] X is a monovalent anion.
[0083] Specific examples of A include methylammonium (MA) cations, ethylammonium (Ethylammonium) cations, and formamidinium. (FA, Formamidinium) cations and other alkylamine compound ions, potassium cations, cesium cations and rubidium cations and other alkali metal ions.
[0084] It should be noted that the perovskite compound of this embodiment may contain a variety of chemical species as A. From the viewpoint of photoelectric conversion efficiency and durability, the perovskite compound preferably contains cesium cations, methylammonium cations, and formamidinium cations.
[0085] Specific examples of M include divalent metal ions such as lead, tin, antimony, indium, copper, bismuth, and germanium.
[0086] It should be noted that the perovskite compound of this embodiment may contain a variety of chemical species as M. From the viewpoint of photoelectric conversion efficiency and durability, the perovskite compound preferably contains at least one of lead cations and tin cations.
[0087] Specific examples of X include halide ions such as fluorine, chlorine, bromine, and iodine.
[0088] It should be noted that the perovskite compound of this embodiment may contain a variety of chemical species as X. From the viewpoint of photoelectric conversion efficiency and durability, the perovskite compound preferably contains at least one of bromine and iodine.
[0089] The chemical species and their composition used as A, M, and X can be appropriately adjusted according to the performance requirements of the photoelectric conversion element. In other words, the photoelectric conversion element 1 of this embodiment can have its performance, such as durability and absorption wavelength, adjusted by modifying the chemical species and their composition used as A, M, and X.
[0090] It should be noted that the main component of the photoelectric conversion layer of this disclosure is not limited to perovskite compounds. For example, the main component of the photoelectric conversion layer of this disclosure can be silicon or cuprous oxide. That is, the photoelectric conversion layer of this disclosure can be made of any material as long as it is a material capable of absorbing incident light and generating charge carriers, i.e., a photoelectric conversion material.
[0091] However, as described later, the photoelectric conversion layer of this disclosure contains inorganic nanoparticles (NPs) distributed internally. Therefore, from the viewpoint of ease of manufacture, the photoelectric conversion layer of this disclosure preferably uses a material that can be formed using a solution method. That is, the photoelectric conversion element of this disclosure has a particular effect of simplifying the manufacturing process when the material of the photoelectric conversion layer is a perovskite compound or similar material.
[0092] like Figure 1As shown, the photoelectric conversion layer 14 of this embodiment includes a photoelectric conversion band 141 and a reflection suppression band 142. Here, the photoelectric conversion band 141 refers to the region in the photoelectric conversion layer 14 of this embodiment where inorganic nanoparticles NP are not distributed, and the reflection suppression band 142 refers to the region in the photoelectric conversion layer 14 of this embodiment where inorganic nanoparticles NP are distributed.
[0093] The photoelectric conversion band 141 is a dense layer made of photoelectric conversion material; in this embodiment, it is a dense layer made of perovskite compound. As described above, the photoelectric conversion band 141 is a region where nanoparticles (NPs) are absent. The main surface of the photoelectric conversion band 141 on the positive z-axis abuts against the second carrier transport layer 15, and the main surface on the negative z-axis abuts against the first carrier transport layer 13 across the reflection suppression band 142. The photoelectric conversion band 141 generates carriers by absorbing incident light.
[0094] It should be noted that the statement "no nanoparticles NP exist" here does not necessarily mean that nanoparticles NP do not exist in a strict sense. That is, the statement "does not contain nanoparticles NP" here allows a small number of nanoparticles NP to be unintentionally mixed into the photoelectric conversion band 141 during the manufacturing process, etc.
[0095] From the viewpoint of improving carrier transport efficiency, it is preferable that the photoelectric conversion band 141 and the first carrier transport layer 13 are not strictly isolated by inorganic nanoparticles NP. In other words, at the interface between the photoelectric conversion layer 14 and the first carrier transport layer 13, it is preferable that there is a region where the photoelectric conversion band 141 and the first carrier transport layer 13 are in contact without being separated by nanoparticles NP.
[0096] like Figure 1 As shown, in this embodiment, the reflection suppression band 142 and the first carrier transport layer 13 are spatially electrically connected through a dense portion composed of photoelectric conversion material distributed in a manner that fills the gaps between inorganic nanoparticles NP. With this configuration, the photoelectric conversion element 1 of this embodiment can improve the carrier transport efficiency.
[0097] The reflection suppression band 142 is a layered region containing inorganic nanoparticles NP that are at least one of an insulator and a semiconductor. In other words, the reflection suppression band 142 is a region in the photoelectric conversion layer 14 in which inorganic nanoparticles NP are distributed.
[0098] like Figure 1 As shown, the reflection suppression band 142 of this embodiment is composed of a dense portion consisting of layered inorganic nanoparticles NP and photoelectric conversion material distributed in a manner that fills the gaps between the inorganic nanoparticles NP.
[0099] like Figure 1As shown, the reflection suppression band 142 of this embodiment is located between the photoelectric conversion band 141 and the first carrier transport layer 13, and contains inorganic nanoparticles NP that serve as insulators or semiconductors.
[0100] In the reflection suppression band 142, light incident from the negative z-axis is scattered by distributed inorganic nanoparticles (NPs). As a result, the reflection suppression band 142 of this embodiment can suppress the reflection of incident light.
[0101] If the reflection suppression band 142 suppresses the reflection of incident light, the amount of light supplied to the photoelectric conversion band 141 increases. As a result, the photoelectric conversion element 1 of this embodiment can improve the photoelectric conversion efficiency.
[0102] The inorganic nanoparticles NP are at least one of insulators and semiconductors, for example, they can be metal oxides.
[0103] When inorganic nanoparticles (NPs) are insulators, examples of main components of inorganic nanoparticles (NPs) include, for example, silicon dioxide and aluminum nitride.
[0104] When inorganic nanoparticles (NPs) are semiconductors, the main components of inorganic nanoparticles (NPs) can be, for example, zirconium oxide, yttrium oxide, silicon carbide, and titanium dioxide.
[0105] From the viewpoint of suppressing the reflection of incident light, the average particle size of the inorganic nanoparticles (NPs) is preferably greater than 11 nm, more preferably 15 nm or more, and particularly preferably 45 nm or more. Furthermore, from the viewpoint of improving photoelectric conversion efficiency, the average particle size of the inorganic nanoparticles (NPs) is preferably 122 nm or less.
[0106] When the main component of inorganic nanoparticles is an insulator, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably less than 200 nm, more preferably 59 nm to 110 nm, and particularly preferably 61 nm to 87 nm.
[0107] Furthermore, when the main component of the inorganic nanoparticles is a semiconductor, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably 200 nm or less, more preferably 19 nm to 86 nm, and particularly preferably 30 nm to 86 nm.
[0108] From the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably less than 0.26 times the thickness of the photoelectric conversion layer 14, more preferably 0.05 to 0.20 times, and particularly preferably 0.08 to 0.13 times.
[0109] In other words, the thickness of the reflection suppression band 142 is preferably less than 0.26 times the total thickness of the photoelectric conversion band and the reflection suppression band, more preferably 0.05 to 0.20 times, and particularly preferably 0.08 to 0.13 times.
[0110] More specifically, when the main component of the inorganic nanoparticles is an insulator, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably less than 0.26 times the thickness of the photoelectric conversion layer 14, more preferably 0.08 to 0.16 times, and particularly preferably 0.08 to 0.12 times.
[0111] In other words, when the main component of the inorganic nanoparticles is an insulator, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably less than 0.26 times the total thickness of the photoelectric conversion band 141 and the reflection suppression band 142, more preferably 0.08 times to 0.16 times, and particularly preferably 0.08 times to 0.12 times.
[0112] Furthermore, when the main component of the inorganic nanoparticles is a semiconductor, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably 0.24 times or less than the thickness of the photoelectric conversion layer 14, more preferably 0.05 times to 0.20 times, and particularly preferably 0.08 times to 0.13 times.
[0113] In other words, when the main component of the inorganic nanoparticles is semiconductor, from the viewpoint of improving photoelectric conversion efficiency, the thickness of the reflection suppression band 142 is preferably less than 0.24 times the total thickness of the photoelectric conversion band 141 and the reflection suppression band 142, more preferably 0.05 times to 0.20 times, and particularly preferably 0.08 times to 0.13 times.
[0114] It should be noted that the thickness of the reflection suppression band mentioned here can be defined as the distance from the upper end to the lower end of the vertical cross section of the photoelectric conversion element.
[0115] The thickness of the reflection suppression band can be determined, for example, by observation using a scanning electron microscope (SEM). In this case, the thickness of the reflection suppression band can be measured in a cross-sectional SEM image as the distance from the upper end of the layer located below the reflection suppression band to the uppermost point of the nanoparticle at the site of maximum nanoparticle deposition. Alternatively, the thickness of the reflection suppression band can also be calculated as the average of multiple values measured from cross-sectional SEM images taken in multiple fields of view, i.e., multiple cross-sectional SEM images taken from different cut surfaces.
[0116] In addition, the thickness of the photoelectric conversion band mentioned here can be defined as the distance from the upper end to the lower end of the vertical cross section of the photoelectric conversion element.
[0117] The thickness of the photoelectric conversion band can be determined, for example, by observation using a scanning electron microscope (SEM). In this case, the thickness of the photoelectric conversion band can be measured in a cross-sectional SEM image as the distance from the upper end of the layer located below the photoelectric conversion band to the uppermost point of the nanoparticle at the site of maximum nanoparticle deposition. Alternatively, the thickness of the photoelectric conversion band can also be calculated as the average of multiple values measured from cross-sectional SEM images taken in multiple fields of view, i.e., multiple cross-sectional SEM images taken from different cut surfaces.
[0118] Furthermore, the thickness of the photoelectric conversion layer can be defined as the distance from the upper end of the reflection suppression band or the photoelectric conversion band to the lower end of the vertical cross section of the photoelectric conversion element.
[0119] The thickness of the photoelectric conversion layer can be determined, for example, by observation using a scanning electron microscope (SEM). In this case, the thickness of the photoelectric conversion band can be measured in a cross-sectional SEM as the distance from the uppermost end of the reflection suppression band or the photoelectric conversion band to the lowermost end of the reflection suppression band or the photoelectric conversion band.
[0120] In addition, the thickness of the photoelectric conversion layer can also be calculated as the average of multiple values measured from cross-sectional SEM images taken in multiple fields of view, i.e., multiple cross-sectional SEM images taken from different cut surfaces.
[0121] In addition, the thickness of the photoelectric conversion band can also be calculated by summing the individual measurement results of the thickness of the reflection suppression band and the thickness of the photoelectric conversion band.
[0122] It should be noted that although the reflection suppression band 142 of this disclosure is part of the photoelectric conversion layer 14, the configuration of the reflection suppression band 142 of this disclosure is not limited thereto.
[0123] For example, in the photoelectric conversion element of this disclosure, inorganic nanoparticles can be distributed within the first electrode layer. In this case, the photoelectric conversion layer is a uniform layer that does not contain inorganic nanoparticles. Furthermore, in this case, the entire region of the photoelectric conversion layer can be referred to as the photoelectric conversion band, and the region within the first electrode layer where inorganic nanoparticles are distributed can be referred to as the reflection suppression band.
[0124] Furthermore, in the photoelectric conversion element disclosed herein, the reflection suppression band can be distributed within the photoelectric conversion band. That is, there can also be a photoelectric conversion band where the upper and lower parts of the region containing inorganic nanoparticles do not contain inorganic nanoparticles.
[0125] Furthermore, in the photoelectric conversion element of this disclosure, inorganic nanoparticles can be distributed within different layers located between the photoelectric conversion layer and the first electrode layer. In this case, the photoelectric conversion layer 14 of this disclosure is formed as a uniform layer that does not contain inorganic nanoparticles, and its entire region can be referred to as the photoelectric conversion band. Alternatively, in this case, the region where inorganic nanoparticles are distributed can be referred to as the reflection suppression band.
[0126] That is, the reflection suppression band of this disclosure is located between the photoelectric conversion band and the first electrode layer, and can be arbitrarily configured as long as it contains inorganic nanoparticles.
[0127] Furthermore, in this disclosure, the statement "the photoelectric conversion element has a reflection suppression layer between the photoelectric conversion band and the first electrode layer" can include cases where the photoelectric conversion element has a reflection suppression band inside the photoelectric conversion band or the first electrode layer.
[0128] That is, in this disclosure, the statement that "the photoelectric conversion element has a reflection suppression layer between the photoelectric conversion band and the first electrode layer" can mean that the photoelectric conversion element has one or more dense layers made of transparent conductive material, has one or more dense layers made of photoelectric conversion material, and has a reflection suppression layer between these dense layers.
[0129] (The structure of the second carrier transport layer 15)
[0130] As described above, the second carrier transport layer 15 in this embodiment is an electron transport layer (ETL). The second carrier transport layer 15 abuts against the photoelectric conversion layer 14 on its main surface on the negative z-axis and against the second electrode layer 16 on its main surface on the positive z-axis. That is, the second carrier transport layer 15 in this embodiment is located between the photoelectric conversion layer 14 and the second electrode layer 16.
[0131] The second carrier transport layer 15 transports the conduction electrons generated in the photoelectric conversion layer 14 to the second electrode layer 16. In other words, the conduction electrons generated in the photoelectric conversion layer 14 are transported to the second electrode layer 16 via the second carrier transport layer 15.
[0132] Examples of compounds that can be used as the main component of the second carrier transport layer 15 include elemental electron transport materials, oxide electron transport materials, sulfide electron transport materials, and organic electron transport materials.
[0133] Specific examples of elemental electron transport materials include silicon and germanium. Specific examples of oxide electron transport materials include oxides of titanium, tin, zinc, iron, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, and tantalum. Specific examples of sulfide electron transport materials include sulfides of cadmium, zinc, lead, silver, antimony, and bismuth. Specific examples of organic electron transport materials include fullerenes.60 , Phenyl C 61 Methyl butyrate (PCBM, [6,6]-Phenyl-C) 61 Fullerene derivatives such as Butyric acid Methyl ester.
[0134] (The structure of the second electrode layer 16)
[0135] The second electrode layer 16 is a conductive layer. The main surface of the second electrode layer 16 on the negative z-axis side abuts against the second carrier transport layer 15.
[0136] The second electrode layer 16 receives the charge carriers generated in the photoelectric conversion layer 14 through the second charge carrier transport layer 15 and outputs them to the outside.
[0137] When the second carrier transport layer 15 is an electron transport layer, the second electrode layer 16 receives the conduction electrons generated in the photoelectric conversion layer 14 as carriers and outputs them to the outside.
[0138] In addition, when the second carrier transport layer 15 is a hole transport layer, the second electrode layer 16 receives the holes generated in the photoelectric conversion layer 14 as carriers and outputs them to the outside.
[0139] The second electrode layer 16 can be a light-transmitting electrode layer or a light-non-transmitting electrode layer. That is, the second electrode layer 16 can be a transparent electrode layer or a non-transparent electrode layer. In other words, the photoelectric conversion element 1 of this embodiment can be a transmissive photoelectric conversion element or a non-transmissive photoelectric conversion element.
[0140] It should be noted that, as described above, the photoelectric conversion element 1 of this embodiment has a particularly good effect when used as the upper battery cell of a series-connected solar cell or as the photoelectric conversion element of a solar cell used in the form of window glass. In such cases, the photoelectric conversion element 1 is a transmissive type. That is, in the case described above, the second electrode layer 16 is implemented in the form of a transparent electrode layer.
[0141] When the second electrode layer 16 is a transparent electrode layer, the materials used for the second electrode layer 16 may include, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) with impurities, fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), graphene, and metal nanowires.
[0142] It should be noted that the first electrode layer 12 and the second electrode layer 16 may be made of the same material or of different materials.
[0143] When the second electrode layer 16 is not a transparent electrode layer, the material used for the second electrode layer 16 may include metals such as gold, silver, copper, aluminum, tungsten, titanium, chromium, nickel, and cobalt.
[0144] As described above, the photoelectric conversion element 1 of this embodiment includes a first electrode layer 12, a second electrode layer 16 as transparent electrode layers, and a photoelectric conversion band 141 located between the first electrode layer 12 and the second electrode layer 16. Furthermore, the photoelectric conversion element 1 of this embodiment further includes a reflection suppression band 142 between the photoelectric conversion band and the first electrode layer 12, comprising inorganic nanoparticles NP that are at least one of an insulator and a semiconductor.
[0145] With this configuration, the light incident on the photoelectric conversion element 1 is scattered due to the inorganic nanoparticles NP contained in the reflection suppression band 142, thereby suppressing the reflection of the incident light. As a result, the photoelectric conversion element 1 of this embodiment can improve the photoelectric conversion efficiency.
[0146] (Manufacturing method of photoelectric conversion element)
[0147] Next, the manufacturing method of the photoelectric conversion element of this embodiment will be described in detail. Figure 2 This is a flowchart illustrating a method for manufacturing a photoelectric conversion element according to the first embodiment.
[0148] In the manufacturing method of the photoelectric conversion element of this embodiment, firstly, a substrate 11 on which a first electrode layer 12 is formed is prepared (step ST1).
[0149] It should be noted that process ST1 can be a process of forming the first electrode layer 12 on the substrate 11, or it can be a process of preparing a commercially available transparent electrode substrate.
[0150] Figure 3 This is a cross-sectional schematic diagram used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment. More specifically, Figure 3 This is a cross-sectional schematic diagram showing the structure of the photoelectric conversion element 1 before step ST2 is executed after step ST1 is completed.
[0151] like Figure 3 As shown, in the photoelectric conversion element 1 after step ST1 is completed, a first electrode layer 12 is formed on the substrate 11.
[0152] In the method for manufacturing the photoelectric conversion element of this embodiment, the first carrier transport layer 13 is then formed (step ST2). More specifically, in step ST2, the first carrier transport layer 13 is formed on the first electrode layer 12.
[0153] Examples of methods for forming the first carrier transport layer 13 include coating a solution containing the material of the first carrier transport layer 13 and then allowing the solvent to evaporate, and vacuum evaporating the material of the first carrier transport layer 13. The method for forming the first carrier transport layer 13 can be appropriately selected depending on the material of the first carrier transport layer 13.
[0154] It should be noted that methods for applying the coating solution include, for example, inkjet printing, spraying, molding, and spin coating.
[0155] Figure 4 This is a cross-sectional schematic diagram used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment. More specifically, Figure 4 This is a cross-sectional schematic diagram showing the structure of the photoelectric conversion element 1 before step ST2 is completed and step ST3 is executed.
[0156] like Figure 4 As shown, in the photoelectric conversion element 1 after step ST2 is completed, a first carrier transport layer 13 is formed on the first electrode layer 12.
[0157] In the manufacturing method of the photoelectric conversion element of this embodiment, the photoelectric conversion layer 14 is next formed (step ST3). More specifically, in step ST3, the photoelectric conversion layer 14 is formed on the first carrier transport layer 13. It should be noted that, as described above, the photoelectric conversion layer 14 of this embodiment includes a photoelectric conversion band 141 and a reflection suppression band 142.
[0158] Figure 5 This is a flowchart illustrating a method for manufacturing the photoelectric conversion element according to the first embodiment. More specifically, Figure 5 To show in more detail Figure 2 The flowchart for step ST3 in the process.
[0159] In step ST3, firstly, a nanoparticle dispersion solution is coated (step ST31). More specifically, in step ST31, a nanoparticle dispersion solution is coated on the first carrier transport layer 13.
[0160] It should be noted that methods for applying the coating solution include, for example, inkjet printing, spraying, molding, and spin coating.
[0161] It should be noted that the concentration of the coated nanoparticle dispersion solution can be appropriately set according to the type of nanoparticles used. From the viewpoint of suppressing the reflection of incident light, the concentration of the nanoparticle dispersion solution is preferably 4.0 wt% or less.
[0162] More specifically, from the viewpoint of suppressing the reflection of incident light, when the main component of the nanoparticles is an insulator, the concentration of the nanoparticle dispersion solution is preferably 4.0 wt% or less, more preferably 0.2 wt% to 3.0 wt%, and particularly preferably 1.0 wt% to 2.0 wt%.
[0163] Furthermore, from the viewpoint of suppressing the reflection of incident light, when the main component of the nanoparticles is a semiconductor, the concentration of the nanoparticle dispersion solution is preferably 4.0 wt% or less, more preferably 0.2 wt% to 4.0 wt%, and particularly preferably 2.0 wt% to 4.0 wt%.
[0164] In step ST3, the solvent in the nanoparticle dispersion solution is then evaporated (step ST32).
[0165] By performing step ST32, nanoparticles dispersed in the solution are deposited onto the first carrier transport layer 13. Details will be described later. By forming dense portions of the photoelectric conversion material between the deposited nanoparticles, a reflection suppression band 142 is formed.
[0166] Figure 6 This is a cross-sectional schematic diagram used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment. More specifically, Figure 6 This is a cross-sectional schematic diagram showing the structure of the photoelectric conversion element 1 after step ST32 is completed and before step ST33 is executed.
[0167] like Figure 6 As shown, in the photoelectric conversion element 1 after step ST32 is completed, nanoparticles NP are deposited on the first carrier transport layer 13.
[0168] It should be noted that in the photoelectric conversion element 1 after step ST32 is completed, it can be said that inorganic nanoparticles are uniformly distributed on the first carrier transport layer 13, or that an inorganic nanoparticle layer is formed on the first carrier transport layer 13.
[0169] In step ST3, the precursor solution for the photoelectric conversion band 141 is then coated (step ST33). More specifically, in step ST33, the precursor solution for the photoelectric conversion band 141 is coated on the first carrier transport layer 13 on which nanoparticles NP are deposited. It should be noted that the precursor solution for the photoelectric conversion band referred to here is a solution containing a photoelectric conversion material as a solute; in this embodiment, it is a solution containing a perovskite compound as a solute.
[0170] By performing step ST33, the precursor solution of the photoelectric conversion band 141 is impregnated into the gaps of the deposited nanoparticles NP. In addition, by performing step ST33, a liquid film of the precursor solution is formed on the top of the deposited nanoparticles NP.
[0171] Methods for applying coating solutions include, for example, inkjet printing, spraying, die coating, and spin coating.
[0172] In step ST3, finally, the solvent in the precursor solution of the photoelectric conversion band 141 is evaporated. (Step ST34). The photoelectric conversion layer 14 is formed by performing step ST34.
[0173] By performing step ST34, photoelectric conversion material is deposited in a manner that fills the gaps between the deposited nanoparticles NP, forming a reflection suppression band 142. Additionally, by performing step ST34, photoelectric conversion material is deposited on top of the reflection suppression band 142, forming a photoelectric conversion band 141.
[0174] Figure 7 This is a cross-sectional schematic diagram used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment. More specifically, Figure 7 This is a cross-sectional schematic diagram showing the structure of the photoelectric conversion element 1 before step ST34 is completed and step ST4 is executed.
[0175] like Figure 7 As shown, in the photoelectric conversion element 1 after step ST34 is completed, a photoelectric conversion band 141 is formed on the reflection suppression band 142.
[0176] Return to Figure 2 Explanation.
[0177] In the manufacturing method of the photoelectric conversion element of this embodiment, the second carrier transport layer 15 is then formed (step ST4). More specifically, in step ST4, the second carrier transport layer 15 is formed on the photoelectric conversion layer 14.
[0178] Examples of methods for forming the second carrier transport layer 15 include coating a solution containing the material of the second carrier transport layer 15 and then allowing the solvent to evaporate, and vacuum evaporating the material of the second carrier transport layer 15. The method for forming the second carrier transport layer 15 can be appropriately selected depending on the material of the second carrier transport layer 15.
[0179] It should be noted that methods for applying the coating solution include, for example, inkjet printing, spraying, molding, and spin coating.
[0180] Figure 8 This is a cross-sectional schematic diagram used to explain the manufacturing method of the photoelectric conversion element according to the first embodiment. More specifically, Figure 8 This is a cross-sectional schematic diagram showing the structure of the photoelectric conversion element 1 before step ST5 is executed after step ST4 is completed.
[0181] like Figure 8 As shown, in the photoelectric conversion element 1 after step ST4 is completed, a second carrier transport layer 15 is formed on the photoelectric conversion layer 14.
[0182] In the manufacturing method of the photoelectric conversion element of this embodiment, the photoelectric conversion element 1 is finally completed by forming a second electrode layer (step ST5).
[0183] More specifically, in step ST5, a second electrode layer 16 is formed on the second carrier transport layer 15. By performing step ST5, the photoelectric conversion element of this embodiment becomes... Figure 1 The state shown.
[0184] Examples of methods for forming the second electrode layer 16 include coating a solution containing the material of the second electrode layer 16 and then allowing the solvent to evaporate, and vacuum evaporating the material of the second electrode layer 16. The method for forming the second electrode layer 16 can be appropriately selected depending on the material of the second electrode layer 16.
[0185] It should be noted that methods for applying the coating solution include, for example, inkjet printing, spraying, molding, and spin coating.
[0186] As described above, the method for manufacturing the photoelectric conversion element of this embodiment includes a step of coating a nanoparticle dispersion solution, a step of evaporating the solvent of the nanoparticle dispersion solution, a step of coating a precursor solution for the photoelectric conversion band, and a step of evaporating the solvent of the precursor solution for the photoelectric conversion band. With this manufacturing method, the photoelectric conversion element of this disclosure can be manufactured.
[0187] Example
[0188] The present invention will now be described in more detail with reference to the embodiments, but the present invention is not limited to these embodiments. Hereinafter, "%" refers to "mass %" unless otherwise specified.
[0189] <Fabrication of Photoelectric Conversion Components>
[0190] (Example 1)
[0191] A solution was prepared by dissolving 3PATAT-C3 in N,N-dimethylformamide (DMF). The prepared solution was then spin-coated onto an ITO glass substrate. The coated solution was then annealed to form a hole transport layer.
[0192] It should be noted that these processes are related to Figure 2 Steps ST1 and ST2 correspond to each other.
[0193] Next, silica nanoparticles with an average particle size of 65.8 nm were dispersed in isopropanol at various concentrations to prepare nanoparticle dispersion solutions. The prepared nanoparticle dispersion solutions were then spin-coated onto the formed hole transport layer. The coated nanoparticle dispersion solutions were then annealed. It should be noted that these steps are similar to... Figure 5 Steps ST31 and ST32 correspond to each other.
[0194] It should be noted that the average particle size of the nanoparticles was determined by observation using a scanning electron microscope (SEM).
[0195] For the particle size of the nanoparticles, 12 particles were randomly selected from images captured by a scanning electron microscope for measurement, and the mean and standard deviation were calculated. As mentioned above, the mean was 65.8 nm, and the standard deviation was 3.87. Furthermore, the maximum measured particle size was 117.3 nm, and the minimum was 43.8 nm.
[0196] in,
[0197] The example in which the concentration of the nanoparticle dispersion solution was 0.2 wt% is referred to as Example 1-1.
[0198] Examples in which the concentration of the nanoparticle dispersion solution is 0.4 wt% are designated as Examples 1-2.
[0199] Examples in which the concentration of the nanoparticle dispersion solution is 0.6 wt% are designated as Examples 1-3.
[0200] Examples in which the concentration of the nanoparticle dispersion solution is 0.8 wt% are designated as Examples 1-4.
[0201] Examples in which the concentration of the nanoparticle dispersion solution is 1.0 wt% are designated as Examples 1-5.
[0202] Examples in which the concentration of the nanoparticle dispersion solution is 1.5 wt% are designated as Examples 1-6.
[0203] Examples in which the concentration of the nanoparticle dispersion solution is 2.0 wt% are designated as Examples 1-7.
[0204] Examples in which the concentration of the nanoparticle dispersion solution is 3.0 wt% are designated as Examples 1-8.
[0205] Examples of nanoparticle dispersion solutions with a concentration of 4.0 wt% are referred to as Examples 1-9.
[0206] Next, cesium iodide (CsI), methylammonium bromide (MABr), formamidinium iodide (FAI), lead iodide (PbI2), and lead bromide (PbBr2) were dissolved in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare a precursor solution for the photoelectric conversion band. The prepared precursor solution was then spin-coated onto the deposited nanoparticles, and chlorobenzene was added dropwise to the coated precursor solution. Finally, the coated precursor solution was annealed to form the photoelectric conversion band and the reflection suppression band.
[0207] It should be noted that these processes are related to Figure 5 Steps ST33 and ST34 correspond to each other.
[0208] Next, [6,6]-phenyl C 61 Methyl butyrate was dissolved in 2-propanol to prepare a solution. The prepared solution was then spin-coated onto a substrate with a perovskite layer, and the solvent was dried to form an electron transport layer.
[0209] It should be noted that these processes are related to Figure 2 This corresponds to step ST4 in the text.
[0210] Finally, silver is vacuum-deposited onto the formed electron transport layer to form the second electrode layer, thereby fabricating the photoelectric conversion element of Example 1-1.
[0211] It should be noted that this process is related to... Figure 2 This corresponds to step ST5 in the text.
[0212] (Example 2)
[0213] A solution in which silica nanoparticles with an average particle size of 115.5 nm are dispersed in isopropanol at various concentrations is used as the nanoparticle dispersion solution. Otherwise, the same procedure as in Example 1 is followed to fabricate the photoelectric conversion element.
[0214] It should be noted that, as in Example 1, the average particle size of the nanoparticles was determined by observation using a scanning electron microscope (SEM).
[0215] For the particle size of the nanoparticles, 12 particles were randomly selected from images captured by a scanning electron microscope for measurement, and the mean and standard deviation were calculated. As mentioned above, the mean was 115.5 nm, and the standard deviation was 6.35. Furthermore, the maximum measured particle size was 125.3 nm, and the minimum was 103.2 nm.
[0216] in,
[0217] The example in which the concentration of the nanoparticle dispersion solution was 0.2 wt% is referred to as Example 2-1.
[0218] The example in which the concentration of the nanoparticle dispersion solution was 0.4 wt% is referred to as Example 2-2.
[0219] Examples 2-3 show that the concentration of the nanoparticle dispersion solution was 0.6 wt%.
[0220] Examples 2-4 show that the concentration of the nanoparticle dispersion solution was 0.8 wt%.
[0221] Examples 2-5 show the nanoparticle dispersion solution with a concentration of 1.0 wt%.
[0222] Examples 2-6 show the nanoparticle dispersion solution with a concentration of 1.5 wt%.
[0223] Examples 2-7 show the nanoparticle dispersion solution with a concentration of 2.0 wt%.
[0224] Examples 2-8 show that the concentration of the nanoparticle dispersion solution was 3.0 wt%.
[0225] Examples of nanoparticle dispersion solutions with a concentration of 4.0 wt% are referred to as Examples 2-9.
[0226] (Example 3)
[0227] The photoelectric conversion element was fabricated by dispersing zirconium oxide nanoparticles with an average particle size of 13.4 nm in a solution of isopropanol at various concentrations as a nanoparticle dispersion solution. Otherwise, the same procedure as in Example 1 was followed.
[0228] It should be noted that, as in Example 1, the average particle size of the nanoparticles was determined by observation using a scanning electron microscope (SEM).
[0229] For the particle size of the nanoparticles, 12 particles were randomly selected from images captured by a scanning electron microscope for measurement, and the mean and standard deviation were calculated. As mentioned above, the mean was 13.4 nm, and the standard deviation was 2.16. Furthermore, the maximum measured particle size was 10.0 nm, and the minimum was 17.2 nm.
[0230] in,
[0231] The example in which the concentration of the nanoparticle dispersion solution was 0.2 wt% is referred to as Example 3-1.
[0232] Examples of nanoparticle dispersion solutions with a concentration of 0.4 wt% are referred to as Examples 3-2.
[0233] Examples where the concentration of the nanoparticle dispersion solution is 0.5 wt% are designated as Examples 3-3.
[0234] Examples 3-4 show that the concentration of the nanoparticle dispersion solution is 0.6 wt%.
[0235] Examples 3-5 show the nanoparticle dispersion solution with a concentration of 0.8 wt%.
[0236] Examples 3-6 refer to those in which the concentration of the nanoparticle dispersion solution is 1.0 wt%.
[0237] Examples 3-7 show the nanoparticle dispersion solution with a concentration of 1.5 wt%.
[0238] Examples 3-8 show that the concentration of the nanoparticle dispersion solution was 2.0 wt%.
[0239] Examples 3-9 show the nanoparticle dispersion solution with a concentration of 2.5 wt%.
[0240] Examples of nanoparticle dispersion solutions with a concentration of 3.0 wt% are designated as Examples 3-10.
[0241] Examples of nanoparticle dispersion solutions with a concentration of 4.0 wt% are referred to as Examples 3-11.
[0242] (Example 4)
[0243] The photoelectric conversion element was fabricated by dispersing yttrium(III) nanoparticles in isopropanol solutions at various concentrations as nanoparticle dispersion solutions, otherwise, the same procedure as in Examples 1-1 was followed.
[0244] in,
[0245] The example in which the concentration of the nanoparticle dispersion solution was 0.2 wt% is referred to as Example 4-1.
[0246] The example in which the concentration of the nanoparticle dispersion solution was 0.4 wt% is referred to as Example 4-2.
[0247] Examples of nanoparticle dispersion solutions with a concentration of 0.6 wt% are designated as Examples 4-3.
[0248] Examples in which the concentration of the nanoparticle dispersion solution is 0.8 wt% are designated as Examples 4-4.
[0249] Examples 4-5 show the nanoparticle dispersion solution with a concentration of 1.0 wt%.
[0250] Examples 4-6 show the nanoparticle dispersion solution with a concentration of 1.5 wt%.
[0251] Examples 4-7 show the nanoparticle dispersion solution with a concentration of 2.0 wt%.
[0252] Examples 4-8 show the nanoparticle dispersion solution with a concentration of 2.5 wt%.
[0253] Examples 4-9 show the nanoparticle dispersion solution with a concentration of 3.0 wt%.
[0254] Examples 4-10 show that the concentration of the nanoparticle dispersion solution was 3.0 wt%.
[0255] Examples of nanoparticle dispersion solutions with a concentration of 4.0 wt% are referred to as Examples 4-11.
[0256] (Comparative Example 1)
[0257] No reflection suppression band is formed. Otherwise, the photoelectric conversion element is manufactured in the same manner as in Example 1.
[0258] (Comparative Example 2)
[0259] The photoelectric conversion element was fabricated by dispersing silica nanoparticles with an average particle size of 19.3 nm in a solution of isopropanol at various concentrations as a nanoparticle dispersion solution. Otherwise, the same procedure as in Example 1 was followed.
[0260] It should be noted that, as in Example 1, the average particle size of the nanoparticles was determined by observation using a scanning electron microscope (SEM).
[0261] For the particle size of the nanoparticles, 12 particles were randomly selected from images captured by a scanning electron microscope for measurement, and the mean and standard deviation were calculated. As mentioned above, the mean was 19.3 nm, and the standard deviation was 3.87. Furthermore, the maximum measured particle size was 27.0 nm, and the minimum was 11.9 nm.
[0262] in,
[0263] A comparative example with a nanoparticle dispersion solution concentration of 0.2 wt% was used as Comparative Example 2-1.
[0264] A comparative example with a nanoparticle dispersion solution concentration of 0.4 wt% was used as Comparative Example 2-2.
[0265] Comparative examples with a nanoparticle dispersion concentration of 0.6 wt% are designated as Comparative Examples 2-3.
[0266] Comparative examples with a nanoparticle dispersion concentration of 0.8 wt% are designated as Comparative Examples 2-4.
[0267] Comparative examples with a nanoparticle dispersion concentration of 1.0 wt% are designated as Comparative Examples 2-5.
[0268] Comparative examples with a nanoparticle dispersion concentration of 1.5 wt% are designated as Comparative Examples 2-6.
[0269] Comparative examples with a nanoparticle dispersion concentration of 2.0 wt% are designated as Comparative Examples 2-7.
[0270] Comparative examples with a nanoparticle dispersion concentration of 3.0 wt% are designated as Comparative Examples 2-8.
[0271] Comparative examples with a nanoparticle dispersion concentration of 4.0 wt% are designated as Comparative Examples 2-9.
[0272] <Estimation of the magnitude of short-circuit current density lost due to light reflection>
[0273] A solar simulator using AM (Air Mass) 1.5G was used to illuminate the fabricated photoelectric conversion element, and the reflectivity of the light was measured. Based on the measured reflectivity, the magnitude of the short-circuit current density lost due to light reflection was estimated. The estimation results are presented below. Figure 9 , Figure 10 , Figure 11 and Figure 12 .
[0274] Figure 9 This is a graph showing the estimated short-circuit current density lost due to light reflection. More specifically, Figure 9The graph is a plot of the estimated short-circuit current density of the photoelectric conversion element in Example 1 and the estimated short-circuit current density of the photoelectric conversion element in Comparative Example 2 relative to the concentration of the dispersion solution.
[0275] Figure 10 This is a graph showing the estimated short-circuit current density lost due to light reflection. More specifically, Figure 10 The graph is a plot of the estimated short-circuit current density of the photoelectric conversion element in Example 2 and the estimated short-circuit current density of the photoelectric conversion element in Comparative Example 2 relative to the concentration of the dispersion solution.
[0276] Figure 11 This is a graph showing the estimated short-circuit current density lost due to light reflection. More specifically, Figure 11 The graph is a plot of the estimated short-circuit current density of the photoelectric conversion element in Example 3 and the estimated short-circuit current density of the photoelectric conversion element in Comparative Example 2 relative to the concentration of the dispersion solution.
[0277] Figure 12 This is a graph showing the estimated short-circuit current density lost due to light reflection. More specifically, Figure 12 The graph is a plot of the estimated short-circuit current density of the photoelectric conversion element in Example 4 and the estimated short-circuit current density of the photoelectric conversion element in Comparative Example 2 relative to the concentration of the dispersion solution.
[0278] according to Figure 9 and Figure 10 The results show that, when the main component of inorganic nanoparticles is silicon dioxide, considering the standard deviation, if the average particle size of inorganic nanoparticles is greater than 15 nm, the loss of short-circuit current density caused by light reflection can be suppressed.
[0279] In addition, according to Figure 9 and Figure 10 The results show that, when the main component of inorganic nanoparticles is silicon dioxide, considering the standard deviation, if the average particle size of inorganic nanoparticles is below 122 nm, the loss of short-circuit current density caused by light reflection can be further suppressed.
[0280] In addition, according to Figure 9 and Figure 10 The results show that when the main component of the inorganic nanoparticles is silicon dioxide, the concentration of the dispersion solution is preferably 0.2 wt% to 3.0 wt%, and particularly preferably 1.0 wt% to 2.0 wt%.
[0281] according to Figure 11The results show that, when the main component of inorganic nanoparticles is zirconium oxide, considering the standard deviation, if the average particle size of inorganic nanoparticles is above 11 nm, the loss of short-circuit current density caused by light reflection can be suppressed.
[0282] In addition, according to Figure 11 The results show that when the main component of the inorganic nanoparticles is zirconium oxide, the concentration of the dispersion solution is preferably 0.2 wt% to 4.0 wt%, and particularly preferably 2.0 wt% to 4.0 wt%.
[0283] according to Figure 12 The results show that when the main component of the inorganic nanoparticles is yttrium oxide, the concentration of the dispersion solution is preferably 0.2 wt% to 4.0 wt%, and particularly preferably 2.0 wt% to 4.0 wt%.
[0284] <Thickness Measurement of Reflection Suppression Band in Photoelectric Conversion Element>
[0285] In some embodiments, the cross-section of the fabricated photoelectric conversion element was observed using a scanning electron microscope (SEM) to determine the thickness of the reflection suppression band and the photoelectric conversion layer. The results are shown in Tables 1, 2, and 3.
[0286] More specifically, cross-sectional SEM images were captured from three fields of view. The captured cross-sectional SEM images of the photoelectric conversion element were observed, and the distance from the upper end of the layer located below the reflection suppression band to the uppermost point of the nanoparticles at the site of maximum nanoparticle deposition was measured. Then, the average of the distances measured in each field of view was calculated as the thickness of the reflection suppression band.
[0287] In addition, the distance from top to bottom of the photoelectric conversion layer was measured by observing the cross-sectional SEM image of the photoelectric conversion element. Then, the average value of the distances measured in each field of view was calculated as the thickness of the photoelectric conversion layer.
[0288] It should be noted that during the measurement, 3 to 5 photoelectric conversion elements were fabricated for each embodiment and comparative example, and their average value was calculated.
[0289] <Battery Performance Evaluation of Photoelectric Conversion Components>
[0290] For some embodiments, an AM (Air Mass) 1.5G solar simulator was used to irradiate the fabricated photoelectric conversion element, and the open-circuit voltage and photoelectric conversion efficiency were measured. The results are shown in Tables 1, 2, and 3.
[0291] It should be noted that during the measurement, 3 to 5 photoelectric conversion elements were fabricated for each embodiment and comparative example, and their average value was calculated.
[0292] [Table 1]
[0293]
[0294] [Table 2]
[0295]
[0296] [Table 3]
[0297]
[0298] Based on the results in Tables 1, 2 and 3, it is shown that the photoelectric conversion element of this embodiment can improve the photoelectric conversion efficiency by having a reflection suppression band.
[0299] (Examination in Table 1)
[0300] A comparison of Examples 1-2, 1-3, 1-4, 1-5, 1-6 and 2-6 with Examples 2-9 shows that when the main component of the inorganic nanoparticles is silicon dioxide, the thickness of the reflection suppression band is preferably 59 nm to 110 nm.
[0301] Furthermore, a comparison of Examples 1-3, 1-5, and 1-6 with Examples 1-2, 1-4, and 2-6 shows that when the main component of the inorganic nanoparticles is silicon dioxide, the thickness of the reflection suppression band is particularly preferably 61 nm to 87 nm.
[0302] Based on the comparison of Examples 1-2, 1-3, 1-4, 1-5, 1-6 and 2-6 with Examples 2-9, it is shown that when the main component of the inorganic nanoparticles is silicon dioxide, the thickness of the reflection suppression band is preferably 0.08 to 0.26 times the thickness of the photoelectric conversion layer, and more preferably 0.08 to 0.16 times.
[0303] Furthermore, a comparison of Examples 1-2, 1-3, 1-4, 1-5, and 1-6 with Examples 2-6 and 2-9 shows that when the main component of the inorganic nanoparticles is silicon dioxide, the thickness of the reflection suppression band is particularly preferably 0.08 to 0.12 times the thickness of the photoelectric conversion layer.
[0304] (Examination in Table 2)
[0305] Based on the results of Examples 3-3, 3-6, 3-7, 3-8, 3-9 and 3-10, it is shown that when the main component of the inorganic nanoparticles is zirconium oxide, the thickness of the reflection suppression band is preferably 19 nm to 86 nm.
[0306] Furthermore, a comparison of Examples 3-6, 3-7, 3-8, 3-9, and 3-10 with Example 3-3 shows that when the main component of the inorganic nanoparticles is zirconium oxide, the thickness of the reflection suppression band is particularly preferably 30 nm to 86 nm.
[0307] (Examination in Table 3)
[0308] Based on the results of Examples 4-5, 4-7, 4-8, 4-9, 4-10 and 4-11, it is shown that when the main component of the inorganic nanoparticles is yttrium oxide, the thickness of the reflection suppression band is preferably 102 nm to 182 nm.
[0309] (Examination of Tables 2 and 3)
[0310] Based on the results of Examples 3-3, 3-6, 3-7, 3-8, 3-9, 3-10, 4-5, 4-7, 4-8, 4-9, 4-10, and 4-11, it is shown that when the main component of the inorganic nanoparticles is semiconductor, the thickness of the reflection suppression band is preferably 0.03 to 0.24 times the thickness of the photoelectric conversion layer.
[0311] Furthermore, based on the comparison between Examples 3-6, 3-7, 3-8, 3-9, 3-10, 4-5, 4-7, 4-8, and 4-9 and Examples 3-3, 4-10, and 4-11, it is shown that when the main component of the inorganic nanoparticles is semiconductor, the thickness of the reflection suppression band is further preferably 0.05 to 0.20 times the thickness of the photoelectric conversion layer.
[0312] Furthermore, based on the comparison between Examples 3-7, 3-8, 3-9, and 3-10 and Examples 3-3, 3-6, 4-5, 4-7, 4-8, 4-9, 4-10, and 4-11, it is shown that when the main component of the inorganic nanoparticles is semiconductor, the thickness of the reflection suppression band is particularly preferably 0.08 to 0.13 times the thickness of the photoelectric conversion layer.
[0313] The present invention has been described above based on the above embodiments, but the present invention is not limited to the above embodiments. Of course, it includes various modifications, alterations and combinations that can be made by those skilled in the art within the scope of the technical solutions claimed in this application.
Claims
1. A photoelectric conversion element comprising: a first electrode layer serving as a transparent electrode, a second electrode layer, and a photoelectric conversion band located between the first electrode layer and the second electrode layer. A reflection suppression band comprising inorganic nanoparticles that are at least one of an insulator and a semiconductor is further provided between the photoelectric conversion band and the first electrode layer. The thickness of the reflection suppression band is less than 0.26 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
2. The photoelectric conversion element according to claim 1, wherein, The thickness of the reflection suppression band is 0.05 to 0.20 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
3. The photoelectric conversion element according to claim 2, wherein, The thickness of the reflection suppression band is 0.08 to 0.13 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.
4. The photoelectric conversion element according to claim 3, wherein, The inorganic nanoparticles contain zirconium oxide as the main component.
5. The photoelectric conversion element according to claim 3, wherein, The inorganic nanoparticles contain silicon dioxide as the main component. The thickness of the reflection suppression band is 0.08 to 0.12 times the sum of the thickness of the photoelectric conversion band and the thickness of the reflection suppression band.