Hole transport body, photoelectric conversion element, and composition

Abstract

This hole transport body contains an organic semiconductor and a nonionic surfactant having a critical micelle concentration with respect to pure water of 0.001 g / L or more and 0.080 g / L or less. A photoelectric conversion element (100) according to the present disclosure is provided with a first electrode (2), a photoelectric conversion layer (4), a hole transport layer (5), and a second electrode (6). The hole transport layer (5) contains the hole transport body according to the present disclosure. The composition for producing a hole transport body according to the present disclosure comprises an organic semiconductor, a nonionic surfactant having a critical micelle concentration with respect to pure water of 0.001 g / L or more and 0.080 g / L or less, and a solvent.

Description

Technical Field

[0001] This disclosure relates to hole transporters, photoelectric conversion elements, and compositions thereof. Background Technology

[0002] Semiconductor devices using silicon, an inorganic semiconductor material, require high-temperature and high-vacuum processes during their formation. Therefore, it is difficult to achieve large-area and low-cost production of silicon-based semiconductor devices.

[0003] On the other hand, compared with conventional inorganic semiconductor devices that utilize inorganic semiconductor materials, organic semiconductor devices utilizing organic semiconductor materials can be applied to a variety of applications due to reasons such as the ability to reduce the manufacturing process temperature and the fact that organic semiconductor materials are readily soluble in solvents and can be easily deposited using processes such as coating. For example, Patent Document 1 discloses a photoelectric conversion element that uses organic semiconductor materials in a buffer layer between the active layer and the electrode.

[0004] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2019-175970 Non-patent literature Non-patent literature 1: Sander Kommeren and five others, Organic Electronics, Vol. 61, 2018, pp. 282-288 Summary of the Invention

[0005] The problem that the invention aims to solve The purpose of this disclosure is to provide a hole transporter suitable for improving the photoelectric conversion efficiency of photoelectric conversion elements.

[0006] Methods for solving problems This disclosure relates to a hole transporter, comprising: Organic semiconductors, and Nonionic surfactants with a critical micelle concentration in pure water of ≥0.001 g / L and ≤0.080 g / L.

[0007] Invention Effects This disclosure provides a hole transporter suitable for improving the photoelectric conversion efficiency of photoelectric conversion elements. Attached Figure Description

[0008] Figure 1 This is a cross-sectional view showing the photoelectric conversion element of the third embodiment.

[0009] Figure 2 This is a cross-sectional view showing a first modified example of the photoelectric conversion element according to the third embodiment.

[0010] Figure 3 This is a cross-sectional view showing a second modified example of the photoelectric conversion element according to the third embodiment. Detailed Implementation

[0011] [The insights that form the basis of this disclosure] Organic semiconductor materials used in organic semiconductor devices require high charge mobility. Additionally, materials for transporting holes, such as those used in hole transport layers for photoelectric conversion elements, can be polymers with π-conjugated molecular structures. However, π-conjugated molecules exhibit significant anisotropy, with molecules stacking anisotropically, easily forming stereo higher-order structures, making it difficult to obtain homogeneous films. Therefore, to drive devices using these materials, it is necessary to suppress the formation of higher-order structures, improve interlayer interface tightness, and prevent interlayer short circuits caused by gaps.

[0012] To suppress higher-order structures and obtain planar films, dynamic drying processes such as spin coating are generally effective. In this method, after coating a solution containing dissolved semiconductor material, the solvent is rapidly evaporated while applying in-plane stress to the solution, thereby suppressing the formation of higher-order structures and obtaining a planar film. However, in large-area processes, it is difficult to fully control the evaporation conditions, making it difficult to significantly improve manufacturing reliability by adjusting processing conditions. As a method to facilitate film planarization regardless of drying conditions, there is a method of adding planarization-promoting additives to the organic semiconductor material. However, since the additives hinder the electrical conduction of the semiconductor material, there is a problem of degraded device performance.

[0013] For example, when organic semiconductor materials are used in photoelectric conversion elements such as solar cells, it is not easy to improve the photoelectric conversion efficiency of the photoelectric conversion elements.

[0014] Conventionally, hole transport materials, in addition to the organic semiconductor that serves as the hole transporter, also contain dopants, for example, to improve hole mobility. The solvent is adjusted to create conditions that allow these two components to disperse. Therefore, additives that play a role in the higher-order structure of the suppression film have not received much attention until now. With this in mind, the inventors have studied the relationship between surfactants and the properties of photoelectric conversion elements. As a result, it has recently been discovered that hole transporters fabricated using nonionic surfactants as additives improve the photoelectric conversion efficiency of photoelectric conversion elements. Based on this insight, the inventors have completed the hole transporter and photoelectric conversion element disclosed herein.

[0015] Non-patent document 1 reports that the characteristics of solar cells are maximized when an anionic surfactant is added to an aqueous solution containing a hole transport material.

[0016] The inventors conducted a detailed investigation into the effects of surfactants added to hole transporters containing organic semiconductor materials on the characteristics of photoelectric conversion elements. The results showed that by using nonionic surfactants with critical micelle concentrations within a specific range, or by using specific nonionic surfactants, the charge extraction capability and photoelectromotive force from the photoelectric conversion layer were improved, thereby increasing the photoelectric conversion efficiency.

[0017] [Implementation of this disclosure] The embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0018] [First Implementation] In the first embodiment, the hole transporter and composition of the present disclosure will be described.

[0019] The hole transporter of the first embodiment comprises an organic semiconductor and a nonionic surfactant having a critical micelle concentration of 0.001 g / L or more and 0.080 g / L or less for pure water.

[0020] According to the above configuration, in the hole transporter of the first embodiment, the formation of a three-dimensional higher-order structure can be suppressed through the interaction between the nonionic surfactant and the organic semiconductor. Therefore, the charge transport properties between the hole transporter of the first embodiment and other adjacent layers (hereinafter referred to as "adjacent layers") are improved, for example, when constituting a device. Furthermore, the inventors have discovered that nonionic surfactants with a specific critical micelle concentration are less likely to hinder hole transport in organic semiconductors. It should be further noted that the critical micelle concentration for pure water, which is generally an indicator easily estimated experimentally, is linearly correlated with HLB (hydrophile-lipophile balance), an indicator of hydrophilic-lipophilic balance necessary for molecular structure-based calculations. Therefore, the critical micelle concentration is an indicator that facilitates defining the range of effects on solutions where polar and nonpolar molecules coexist, such as hole transporter solutions (i.e., the hole transporter system composition of the first embodiment). Furthermore, the inventors conducted further research and determined that nonionic surfactants, which can achieve various lower critical micelle concentrations, are suitable for improving the photoelectric conversion efficiency of photoelectric conversion elements, rather than ionic surfactants with typically high critical micelle concentrations. Therefore, the hole transporter of the first embodiment is suitable for improving the photoelectric conversion efficiency of photoelectric conversion elements.

[0021] The organic semiconductor contained in the hole transporter of the first embodiment can be a known organic semiconductor capable of transporting holes. Representative examples of organic semiconductors are 2,2',7,7'-tetratetra[N,N-di(p-methoxyphenyl)amino]-9,9'-spirodifluorene (hereinafter referred to as "spiro-OMeTAD"), poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine] (hereinafter referred to as "PTAA"), poly(3-hexylthiophene-2,5-diyl) (hereinafter referred to as "P3HT"), poly(3,4-ethylenedioxythiophene) (hereinafter referred to as "PEDOT"), or copper phthalocyanine (hereinafter referred to as "CuPC").

[0022] The organic semiconductor contained in the hole transporter of the first embodiment may also include at least one selected from spiro-OMeTAD, PTAA, P3HT, PEDOT, CuPC, derivatives of spiro-OMeTAD, derivatives of PTAA, derivatives of P3HT, derivatives of PEDOT, and derivatives of CuPC. According to this configuration, the hole transporter of the first embodiment can further improve the photoelectric conversion efficiency of the photoelectric conversion element.

[0023] In the case of constituting a photoelectric conversion element, in order to further improve the photoelectric conversion efficiency of the photoelectric conversion element, the hole transporter of the first embodiment may, for example, contain the following substances as nonionic surfactants.

[0024] Nonionic surfactants may also contain alkyl hexyl ethers in which the alkyl group has 1 or more but less than 5 carbon atoms. The alkyl group may be linear, for example. The alkyl hexyl ether may also contain at least one selected from methyl hexyl ether, ethyl hexyl ether, n-propyl hexyl ether, n-butyl hexyl ether, and n-pentyl hexyl ether.

[0025] Nonionic surfactants may also include ester compounds obtained by the condensation reaction of sugar alcohols or intramolecular dehydration condensation products of sugar alcohols with fatty acids.

[0026] The ester compounds mentioned above may also include fatty acid esters in which the alkyl group has 12 or more but less than 15 carbon atoms.

[0027] The ester compounds mentioned above may include glycerol fatty acid esters.

[0028] The ester compounds mentioned above may also include sorbitan fatty acid esters.

[0029] The ester compounds mentioned above may also include glycerol monolaurate.

[0030] The ester compounds mentioned above may also include sorbitan monolaurate.

[0031] The aforementioned ester compounds may also include fatty acid esters of intramolecular dehydration condensation products of sugar alcohols modified with polyethylene glycol.

[0032] The polyethylene glycol in the fatty acid ester of the intramolecular dehydration condensation product of a sugar alcohol modified with polyethylene glycol may also contain one or more but no more than 22 ethylene glycol units as constituent monomer units. For example, the polyethylene glycol may also contain 20 ethylene glycol units as constituent monomer units. The fatty acid ester of the intramolecular dehydration condensation product of a sugar alcohol modified with polyethylene glycol can be either a monolaurate or a monooleate.

[0033] Nonionic surfactants may also include copolymers of polyethylene glycol and polypropylene glycol. These copolymers may also contain 6 to 53 ethylene glycol units and 42 to 69 propylene glycol units as constituent monomer units. As an example, block copolymers of ethylene glycol / propylene glycol / ethylene glycol can be cited, such as block copolymers of ethylene glycol pentomer / propylene glycol 68-mer / ethylene glycol pentomer.

[0034] Nonionic surfactants can also contain glucoside derivatives. In other words, a glucoside derivative refers to a molecule containing a glucoside. Glucoside derivatives can also be, for example, alkyl glucoside derivatives. The alkyl group in an alkyl glucoside derivative has, for example, 6 or more but less than 12 carbon atoms. Alkyl glucoside derivatives can also be n-octyl-α-D-glucopyranoside.

[0035] As described above, the critical micelle concentration of the nonionic surfactant is 0.001 g / L or more and 0.080 g / L or less. By using a nonionic surfactant with such a critical micelle concentration, the dispersion of the material in the hole transport solution coated on the photoelectric conversion layer becomes better during the film formation of the hole transport layer. Therefore, the hole transporter of the first embodiment can increase the open-circuit voltage and fill factor of the photoelectric conversion element, thereby improving the photoelectric conversion efficiency.

[0036] The critical micelle concentration of nonionic surfactants in pure water can be determined using the following method. For solutions containing surfactants dissolved in pure water, surface tension is determined using methods such as the Wilhelmy plate method, and the dependence of surface tension on concentration is investigated. The critical micelle concentration is then determined from the concentration of the surfactant at which the surface tension remains unchanged.

[0037] In the hole transporter of the first embodiment, the proportion of nonionic surfactant may be, for example, 0.5% by mass or more and 36% by mass or less. By including nonionic surfactant in such a proportion, the open-circuit voltage and shape factor of the photoelectric conversion element of the hole transporter of the first embodiment are increased, thereby further improving the photoelectric conversion efficiency.

[0038] To improve hole transport capability by doping charge carriers in an organic semiconductor, the hole transporter of the first embodiment may further include a dopant. The dopant, for example, has the effect of increasing the number of holes in the hole transporter. The dopant may also include molecules such as salts that function effectively as dopant.

[0039] The dopant may also include, for example, at least one selected from lithium hexafluorophosphate, lithium fluoroborate, lithium perchlorate, lithium bis(pentafluoroethanesulfonyl)imide, bis(trifluoromethanesulfonyl)amine, lithium bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide, tri[2-(1H-pyrazol-1-yl)-4-tert-butylpyridine]cobalt, 4-isopropyl-4-methyldiphenyliodonium tetra(pentafluorophenyl)borate, tri(pentafluorophenyl)borane, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethane, and 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecylfluoro-29H,31H-phthalocyanine.

[0040] By including the above-mentioned substances as dopants, the hole transporter of the first embodiment can further improve hole transport capability.

[0041] To improve conductivity, hole transporters may further include additives. Examples of additives include supporting electrolytes or solvents.

[0042] The supporting electrolyte and solvent have the effect of stabilizing holes in the hole transporter.

[0043] Examples of supporting electrolytes are ammonium salts, alkaline earth metal salts, or transition metal salts. Examples of ammonium salts include tetrabutylammonium perchlorate, tetraethylammonium hexafluorophosphate, imidazolium salts, or pyridinium salts. Examples of alkali metal salts include lithium perchlorate or potassium tetrafluoroborate. Examples of alkaline earth metal salts include calcium(II) bis(trifluoromethanesulfonyl)imide. Examples of transition metal salts include zinc(II) bis(trifluoromethanesulfonyl)imide or tris[4-tert-butyl-2-(1H-pyrazol-1-yl)pyridine]cobalt(III)tri(trifluoromethanesulfonyl)imide.

[0044] The solvent contained in the hole transporter can be either an organic solvent or a hydrophobic organic solvent. To further stabilize the solute, the solvent in the hole transporter can also be an organic solvent. Examples of organic solvents include heterocyclic compounds such as tert-butylpyridine, pyridine, and N-methylpyrrolidone.

[0045] In the fabrication of the hole transporter according to the first embodiment, the composition of the first embodiment can be used, for example. For instance, the hole transporter of the first embodiment can be formed using the composition of the first embodiment by a coating method or a printing method. Examples of coating methods include doctor blade coating, bar coating, spray coating, dip coating, or spin coating. Examples of printing methods include screen printing.

[0046] The composition of the first embodiment is a hole transport mechanism composition, comprising an organic semiconductor, a nonionic surfactant, and a solvent.

[0047] The organic semiconductor and nonionic surfactant in the composition of the first embodiment are the same as those in the hole transporter of the first embodiment. The solvent may also be a nonpolar solvent. For example, the solvent may include at least one selected from toluene and mesitylene. By including such a solvent, a better dispersion effect of the material in the hole transporter solution (i.e., the hole transporter system composition of the first embodiment) generated by the nonionic surfactant can be obtained during coating and drying.

[0048] The proportion of nonionic surfactant in the composition of the first embodiment may, for example, exceed 0 g / L and be less than 1 g / L. The proportion of nonionic surfactant in the composition of the first embodiment may also exceed 0 g / L and be less than 0.2 g / L, or exceed 0 g / L and be less than 0.1 g / L. The proportion of nonionic surfactant in the composition of the first embodiment may also be 0.05 g / L or more and less than 0.2 g / L, or 0.05 g / L or more and less than 0.1 g / L. By including nonionic surfactant in such proportions, the composition of the first embodiment can produce a hole transporter capable of further improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0049] The contact angle of the composition of the first embodiment relative to the surface of the glass substrate subjected to UV ozone treatment at 24°C can be, for example, 7° or more and 30° or less. By making the composition of the first embodiment have a low contact angle on such a polar surface, the contact between the hole transporter formed using the composition of the first embodiment and the photoelectric conversion layer is improved, the open-circuit voltage and form factor of the photoelectric conversion element are increased, thereby further improving the photoelectric conversion efficiency. In addition, the adhesion of the solution to the photoelectric conversion layer is improved, thereby increasing the yield in the large-area process.

[0050] The contact angle of the composition of the first embodiment can be measured by the following method: A glass substrate is subjected to UV ozone treatment, and the composition of the first embodiment is dropped onto the surface of the glass substrate using a micropipette. The droplet is observed using, for example, a CCD camera, and the contact angle is measured thereby. The contact angle can also be measured using, for example, FAMAS (manufactured by Kyowa Interface Science Co., Ltd.).

[0051] [Second Implementation] In the second embodiment, the hole transporter and composition of the present disclosure will be described.

[0052] The hole transporter in the second embodiment comprises an organic semiconductor and a nonionic surfactant.

[0053] The aforementioned nonionic surfactants include alkyl hexyl ethers in which the alkyl group has 1 or more but less than 5 carbon atoms. The alkyl group is, for example, linear. The alkyl hexyl ether may also contain at least one selected from methyl hexyl ether, ethyl hexyl ether, n-propyl hexyl ether, n-butyl hexyl ether, and n-pentyl hexyl ether.

[0054] Based on the above configuration, in the hole transporter of the second embodiment, the generation of three-dimensional high-order structures can be suppressed through the interaction between the nonionic surfactant and the organic semiconductor. Therefore, the charge transport performance between the hole transporter of the second embodiment and the adjacent layer configured adjacently is improved, for example, when constituting a device.

[0055] The organic semiconductor contained in the hole transporter in the second embodiment can be any material exemplified as an organic semiconductor contained in the hole transporter in the first embodiment.

[0056] In the hole transporter of the second embodiment, the proportion of nonionic surfactant may be, for example, 0.5% by mass or more and 36% by mass or less. By including nonionic surfactant in such a proportion, the open-circuit voltage and shape factor of the photoelectric conversion element of the hole transporter of the second embodiment are increased, thereby further improving the photoelectric conversion efficiency.

[0057] To improve hole transport capability by doping charge carriers in the organic semiconductor, the hole transporter of the second embodiment may further include a dopant. The dopant, for example, has the effect of increasing the number of holes in the hole transporter. The dopant may also include molecules such as salts that function effectively as dopant.

[0058] The dopant contained in the hole transporter of the second embodiment can be the material exemplified as the dopant contained in the hole transporter in the first embodiment.

[0059] To improve conductivity, the hole transporter in the second embodiment may further include additives. Examples of additives are supporting electrolytes or solvents, and materials exemplified as supporting electrolytes or solvents contained in the hole transporter in the first embodiment can be used.

[0060] In the fabrication of the hole transporter according to the second embodiment, the composition of the second embodiment can be used, for example. For instance, the hole transporter of the second embodiment can be formed using the composition of the second embodiment by a coating method or a printing method. Examples of coating methods include doctor blade coating, bar coating, spray coating, dip coating, or spin coating. Examples of printing methods include screen printing.

[0061] The composition of the second embodiment is a hole transport mechanism composition, comprising an organic semiconductor, a nonionic surfactant, and a solvent.

[0062] The organic semiconductor and nonionic surfactant in the composition of the second embodiment are the same as those in the hole transporter of the second embodiment. The solvent may also be a nonpolar solvent. For example, the solvent may include at least one selected from toluene and mesitylene. By including such a solvent, a dispersion effect of the material in the hole transporter solution (i.e., the hole transporter system composition of the second embodiment) generated by the nonionic surfactant can be obtained during coating and drying.

[0063] The proportion of nonionic surfactant in the composition of the second embodiment can, for example, exceed 0 g / L and be less than 1 g / L. The proportion of nonionic surfactant in the composition of the second embodiment can also exceed 0 g / L and be less than 0.2 g / L, or exceed 0 g / L and be less than 0.1 g / L. The proportion of nonionic surfactant in the composition of the second embodiment can also be 0.05 g / L or more and less than 0.2 g / L, or 0.05 g / L or more and less than 0.1 g / L. By including nonionic surfactant in such proportions, the composition of the second embodiment can produce a hole transporter capable of further improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0064] The contact angle of the composition of the second embodiment relative to the surface of the glass substrate subjected to UV ozone treatment at 24°C can be, for example, 7° or more and 30° or less. By making the composition of the second embodiment have a low contact angle on such a polar surface, the contact between the hole transporter formed using the composition of the second embodiment and the photoelectric conversion layer is improved, the open-circuit voltage and form factor of the photoelectric conversion element are increased, thereby further improving the photoelectric conversion efficiency. In addition, the adhesion of the solution to the photoelectric conversion layer is improved, thereby increasing the yield in the large-area process.

[0065] The contact angle of the composition of the second embodiment can be measured using the same method as the method for measuring the contact angle of the composition of the first embodiment.

[0066] [Third Implementation] As a third embodiment, the photoelectric conversion element of this disclosure will be described.

[0067] The photoelectric conversion element of the third embodiment includes a first electrode, a photoelectric conversion layer, a hole transport layer, and a second electrode. The photoelectric conversion element of the third embodiment may also include, for example, the first electrode, the photoelectric conversion layer, the hole transport layer, and the second electrode in sequence. The hole transport layer includes a hole transporter as described in the first or second embodiment.

[0068] The photoelectric conversion element of the third embodiment includes the hole transporter of the first or second embodiment, and therefore has a higher photoelectric conversion efficiency.

[0069] The photoelectric conversion element of the third embodiment can be used, for example, as a solar cell.

[0070] Figure 1 This is a cross-sectional view showing the photoelectric conversion element of the third embodiment. Figure 1 The photoelectric conversion element 100 shown is an example of the configuration of the photoelectric conversion element in the third embodiment.

[0071] The photoelectric conversion element 100 comprises a substrate 1, a first electrode 2, an electron transport layer 3, a photoelectric conversion layer 4, a hole transport layer 5, and a second electrode 6 in sequence.

[0072] The photoelectric conversion element 100 may also not have an electron transport layer 3.

[0073] When light shines on the photoelectric conversion element 100, the photoelectric conversion layer 4 absorbs the light, generating excited electrons and holes. The excited electrons move towards the first electrode 2 through the electron transport layer 3. On the other hand, the holes generated in the photoelectric conversion layer 4 move towards the second electrode 6 via the hole transport layer 5. In this way, the photoelectric conversion element 100 can extract current from the first electrode 2, which is the negative electrode, and the second electrode 6, which is the positive electrode.

[0074] The photoelectric conversion element 100 can be manufactured, for example, by the following methods.

[0075] First, a first electrode 2 is formed on the surface of substrate 1 using chemical vapor deposition (CVD), sputtering, or similar methods. Next, an electron transport layer 3 is formed using CVD, sputtering, solution coating, or similar methods. Then, a photoelectric conversion layer 4 is formed on the electron transport layer 3. For example, a perovskite compound cut to a predetermined thickness can be used as the photoelectric conversion layer 4 and disposed on the electron transport layer 3. Next, a hole transport layer 5 is formed on the photoelectric conversion layer 4 using CVD, sputtering, solution coating, or similar methods. Then, a second electrode 6 is formed on the hole transport layer 5 using CVD, sputtering, solution coating, or similar methods. Through these steps, a photoelectric conversion element 100 is obtained.

[0076] The photoelectric conversion element 100 in the third embodiment may further include a hole transport layer different from the hole transport layer 5 as a second hole transport layer. Figure 2 This is a cross-sectional view showing a first modified example of the photoelectric conversion element according to the third embodiment. The second hole transport layer 8 is disposed between the hole transport layer 5 and the second electrode 6.

[0077] The photoelectric conversion element 200 of the first modification of the third embodiment sequentially includes a substrate 1, a first electrode 2, an electron transport layer 3, a photoelectric conversion layer 4, a hole transport layer 5, a second hole transport layer 8, and a second electrode 6.

[0078] The photoelectric conversion element 200 may also not have an electron transport layer 3.

[0079] The photoelectric conversion element 100 of the third embodiment may further include a porous layer. For example, the porous layer is disposed between the electron transport layer and the photoelectric conversion layer.

[0080] Figure 3 This is a cross-sectional view showing a second modified example of the photoelectric conversion element according to the third embodiment.

[0081] The photoelectric conversion element 300 of the second modification of the third embodiment sequentially includes a substrate 1, a first electrode 2, an electron transport layer 3, a porous layer 7, a photoelectric conversion layer 4, a hole transport layer 5, and a second electrode 6.

[0082] The porous layer 7 comprises porous material. The porous material contains pores.

[0083] Photoelectric conversion element 200 and photoelectric conversion element 300 may also not have an electron transport layer 3.

[0084] The following is a detailed explanation of the various components of a photoelectric conversion element.

[0085] (Substrate 1) Substrate 1 is an accessory component. Substrate 1 serves to hold the layers of the photoelectric conversion element. Substrate 1 can be formed of a transparent material. For example, a glass substrate or a plastic substrate can be used as substrate 1. The plastic substrate can also be, for example, a plastic film.

[0086] When the second electrode 6 is transparent, the substrate 1 can also be formed of a non-transparent material. Such a material can be a metal, ceramic, or a resin material with low transparency.

[0087] If the first electrode 2 has sufficient strength, since each layer can be maintained by means of the first electrode 2, the substrate 1 may not be required.

[0088] (Electrode 1, 2) The first electrode 2 is conductive. The first electrode 2 is transparent. For example, it transmits light from the visible region to the near-infrared region.

[0089] The first electrode 2 is, for example, made of a transparent and conductive material. Examples of such materials are metal oxides or metal nitrides. Examples of such materials include: (i) Titanium oxide doped with at least one of lithium, magnesium, niobium and fluorine. (ii) Gallium oxide doped with at least one of tin and silicon, (iii) Doped with gallium nitride selected from silicon and oxygen, (iv) Tin oxide doped with at least one of antimony and fluorine. (v) Zinc oxide doped with at least one of boron, aluminum, gallium, and indium. (vi) Indium-tin composite oxide, or (vii) Their complex.

[0090] The first electrode 2 can also be formed using an opaque material with a light-transmitting pattern. Examples of light-transmitting patterns include linear, wavy, grid-like, or perforated metallic patterns with multiple fine through-holes arranged regularly or irregularly. If the first electrode 2 has these patterns, light can pass through the parts where no electrode material is present. Examples of opaque electrode materials include platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, iron, nickel, tin, zinc, or alloys containing any of these. Conductive carbon materials can also be used as opaque electrode materials.

[0091] In the absence of an electron transport layer 3 in the photoelectric conversion element, the first electrode 2 blocks holes from the photoelectric conversion layer 4. In this case, there is no ohmic contact between the first electrode 2 and the photoelectric conversion layer 4. Furthermore, the blocking property of holes from the photoelectric conversion layer 4 refers to the property of allowing only electrons generated in the photoelectric conversion layer 4 to pass through while preventing holes from passing through. Materials with this property have a higher Fermi level than the valence band top of the photoelectric conversion layer 4. The Fermi level of materials with this property can also be higher than the Fermi level of the photoelectric conversion layer 4. Aluminum can be cited as a specific example of such a material.

[0092] When the photoelectric conversion element has an electron transport layer 3, the first electrode 2 may not have the ability to block holes from the photoelectric conversion layer 4. In this case, the first electrode 2 may be made of a material capable of forming an ohmic contact with the photoelectric conversion layer 4. In this case, the first electrode 2 may or may not have an ohmic contact with the photoelectric conversion layer 4.

[0093] The light transmittance of the first electrode 2 can be, for example, 50% or more, or 80% or more. The wavelength of the light that the first electrode 2 should transmit depends on the absorption wavelength of the photoelectric conversion layer 4.

[0094] The thickness of the first electrode 2 can be, for example, greater than 1 nm and less than 1000 nm.

[0095] (Electron transport layer 3) Electron transport layer 3 comprises a semiconductor. Electron transport layer 3 may also be formed of a semiconductor with a band gap of 3.0 eV or higher. This allows visible light and infrared light to pass through to photoelectric conversion layer 4. An example of a semiconductor is an inorganic n-type semiconductor.

[0096] Examples of inorganic n-type semiconductors are metal oxides, metal nitrides, or perovskite oxides. Examples of metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, or Cr. Examples of metal oxides include TiO2 or SnO2. Examples of metal nitrides include GaN. Examples of perovskite oxides include SrTiO3 or CaTiO3.

[0097] Electron transport layer 3 can also contain materials with a band gap greater than 6.0 eV. Examples of materials with a band gap greater than 6.0 eV are: (i) Lithium fluoride and alkali metal or alkaline earth metal halides such as calcium fluoride, (ii) Alkali metal oxides such as magnesium oxide, or (iii) Silicon dioxide. In this case, to ensure electron transport, the electron transport layer 3 may also have a thickness of less than 10 nm.

[0098] The electron transport layer 3 may also comprise multiple layers made of different materials.

[0099] (Photoelectric conversion layer 4) The photoelectric conversion layer 4 contains photoelectric conversion materials.

[0100] Photoelectric conversion materials can also be perovskite compounds, for example. That is, photoelectric conversion layer 4 can also contain perovskite compounds. Perovskite compounds have high light absorption coefficients and high carrier mobility in the wavelength region of the solar spectrum. Therefore, photoelectric conversion elements containing perovskite compounds have high photoelectric conversion efficiency.

[0101] Perovskite-type compounds are represented, for example, by the formula ABX3. A is a monovalent cation. Examples of monovalent cations are alkali metal cations or organic cations. An example of an alkali metal cation is the potassium cation (K). + ), cesium cation (Cs) + ) or rubidium cation (Rb + An example of an organic cation is the methylammonium cation (CH3NH3). + ), formamidinium cation (HC(NH2)2) + ), ethylammonium cation (CH3CH2NH3) + ) or guanidinium cation (CH6N3) + B is a divalent cation. An example of a divalent cation is the Sn cation (Sn...). 2+ ), Ge cation (Ge 2+ ) or Pb cation (Pb 2+The divalent cation may also include at least one selected from Sn, Ge, and Pb cations. X is a monovalent anion. An example of a monovalent anion is a halide anion. The sites of A, B, and X may also be occupied by multiple ions.

[0102] The thickness of the photoelectric conversion layer 4 is, for example, 50 nm or more and 10 μm or less.

[0103] The photoelectric conversion layer 4 can be formed, for example, by solution-based coating, printing, or vapor deposition. The photoelectric conversion layer 4 can also be formed by dicing a perovskite-type compound.

[0104] The photoelectric conversion layer 4 may also primarily comprise a perovskite-type compound represented by the formula ABX3. Here, "the photoelectric conversion layer 4 primarily comprises a perovskite-type compound represented by the formula ABX3" means that the photoelectric conversion layer 4 contains at least 90% by mass of a perovskite-type compound represented by the formula ABX3. The photoelectric conversion layer may also contain at least 95% by mass of a perovskite-type compound represented by the formula ABX3. The photoelectric conversion layer 4 may also be composed entirely of a perovskite-type compound represented by the formula ABX3. The photoelectric conversion layer 4 only needs to contain a perovskite-type compound represented by the formula ABX3, but it may also contain defects or impurities.

[0105] The photoelectric conversion layer 4 may further contain other compounds that are different from the perovskite-type compound represented by the formula ABX3. Examples of such other compounds are compounds with a Ruddlesden-Popper type layered perovskite structure.

[0106] (Hole transport layer 5) As described above, the hole transport layer 5 includes a hole transporter according to the first embodiment or the second embodiment. The hole transport layer 5 may also be constructed from a hole transporter according to the first embodiment or the second embodiment.

[0107] The hole transport layer 5 may also comprise multiple layers made of different materials. For example, by stacking multiple layers such that the ionization potential of the hole transport layer 5 decreases sequentially relative to the ionization potential of the photoelectric conversion layer 4, the hole transport characteristics can be improved.

[0108] The thickness of the hole transport layer 5 can be greater than 1 nm and less than 1000 nm, or greater than 10 nm and less than 50 nm. This allows for the expression of sufficient hole transport characteristics, maintains low resistance, and thus achieves high photoelectric conversion efficiency.

[0109] The hole transport layer 5 is formed, for example, by coating, printing, or vapor deposition. This is the same as the photoelectric conversion layer 4. Examples of coating methods include blade coating, bar coating, spray coating, dip coating, or spin coating. An example of printing methods is screen printing. Alternatively, the hole transport layer 5 can be fabricated by mixing multiple materials, followed by pressure application or firing.

[0110] (Electrode 2, 6) The second electrode 6 is conductive. The photoelectric conversion element of the third embodiment includes a hole transport layer 5, therefore the second electrode 6 can also be non-blocking of electrons from the photoelectric conversion layer 4. That is, the material constituting the second electrode 6 can also be a material that makes ohmic contact with the photoelectric conversion layer 4. Therefore, the second electrode 6 can be formed to be transparent.

[0111] In the first electrode 2 and the second electrode 6, only the electrode on the side where light is incident needs to be translucent. Therefore, one of the first electrode 2 and the second electrode 6 may also be opaque. That is to say, one of the first electrode 2 and the second electrode 6 may not use a translucent material, nor may it have a pattern that includes an opening for light to pass through.

[0112] When the second electrode 6 is a light-transmitting electrode, light from the visible region to the near-infrared region can pass through the second electrode 6. The light-transmitting electrode can be formed of a transparent and conductive material.

[0113] Examples of such materials are: (i) Titanium oxide doped with at least one of lithium, magnesium, niobium and fluorine. (ii) Gallium oxide doped with at least one of tin and silicon, (iii) Doped with gallium nitride selected from silicon and oxygen, (iv) Indium-tin composite oxides, (v) Tin oxide doped with at least one of antimony and fluorine. (vi) Zinc oxide doped with at least one of boron, aluminum, gallium, and indium, or (vii) Their complexes.

[0114] Transparent electrodes can be formed using opaque materials with patterns that allow light to pass through. Examples of such patterns include linear, wavy, grid-like, or perforated metallic patterns with multiple fine through-holes arranged regularly or irregularly. If a transparent electrode incorporates these patterns, light can pass through the areas where the electrode material is absent. Examples of opaque materials include platinum, gold, silver, copper, aluminum, rhodium, indium, titanium, iron, nickel, tin, zinc, or alloys containing any of these. Conductive carbon materials can also be used as opaque materials.

[0115] The light transmittance of the second electrode 6 can be 50% or more, or 80% or more. The wavelength of the light transmitted through the second electrode 6 depends on the absorption wavelength of the first photoelectric conversion layer 3. The thickness of the second electrode 6 is, for example, in the range of 1 nm or more and 1000 nm or less.

[0116] (Second Hole Transport Layer 8) The second hole transport layer 8 contains a hole transport material. The second hole transport layer 8 is formed on the hole transport layer 5, for example, by vacuum evaporation.

[0117] The second hole transport layer 8 can also be a p-type inorganic semiconductor. Examples of inorganic semiconductors include Cu₂O, CuGaO₂, CuSCN, CuI, and NiO. x MoO x Carbon materials such as V2O5 or graphene oxide.

[0118] By selecting an inorganic semiconductor as the second hole transport layer 8, damage to the hole transport layer 5 caused during the formation of the second electrode 6 can be mitigated, even when the hole transport layer 5 is an organic semiconductor. Furthermore, short circuits caused by gaps in the hole transport layer 5 can be prevented.

[0119] The second hole transport layer 8 may also contain at least one selected from tungsten oxide and molybdenum oxide. A second hole transport layer 8 containing at least one selected from tungsten oxide and molybdenum oxide can more effectively prevent short circuits caused by gaps in the hole transport layer 5 and also has excellent hole transport properties. Therefore, by having a second hole transport layer 8 with such a configuration, the photoelectric conversion element 200 can achieve higher voltages.

[0120] To increase the voltage of the photoelectric conversion element 200, the second hole transport layer 8 may also have a thickness of 5 nm or more and 40 nm or less. Preferably, the second hole transport layer 8 may also have a thickness of 5 nm or more and 30 nm or less.

[0121] (Porous layer 7) The porous layer 7 is formed on the electron transport layer 3, for example, by a coating method. In the case where the photoelectric conversion element does not have an electron transport layer 3, it is formed on the first electrode 2.

[0122] The porous structure introduced by the porous layer 7 serves as the foundation for the formation of the photoelectric conversion layer 4. The porous layer 7 does not hinder the light absorption of the photoelectric conversion layer 4 or the movement of electrons from the photoelectric conversion layer 4 to the electron transport layer 3.

[0123] The porous layer 7 contains porous material.

[0124] Porous materials are formed, for example, from a series of insulating or semiconductor particles. Examples of insulating particles are alumina particles or silicon oxide particles. Examples of semiconductor particles are inorganic semiconductor particles. Examples of inorganic semiconductors are metal oxides, perovskite oxides of metal elements, sulfides of metal elements, or metal chalcogenides. Examples of metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, or Cr. For example, TiO2 is a metal oxide. Examples of perovskite oxides of metal elements are SrTiO3 or CaTiO3. Examples of sulfides of metal elements are CdS, ZnS, In2S3, PbS, Mo2S, WS2, Sb2S3, Bi2S3, ZnCdS2, or Cu2S. Examples of metal chalcogenides are CsSe, In2Se3, WSe2, HgS, PbSe, or CdTe.

[0125] The thickness of the porous layer 7 can be greater than 0.01 μm and less than 10 μm, or greater than 0.05 μm and less than 1 μm.

[0126] Regarding the surface roughness of the porous layer 7, the surface roughness coefficient, given by the effective area / projected area, can be greater than 10 or greater than 100. The projected area refers to the area of ​​the shadow cast behind the object when light shines on it from directly in front. The actual area refers to the actual surface area of ​​the object. The actual area can be calculated from the volume derived from the object's projected area and thickness, and from the specific surface area and bulk density of the materials constituting the object. Specific surface area can be measured, for example, using the nitrogen adsorption method.

[0127] The pores in the porous layer 7 connect to the portions that contact the photoelectric conversion layer 4 and the portions that contact the electron transport layer 3. In other words, the pores in the porous layer 7 connect one main surface to the other. Thus, the material of the photoelectric conversion layer 4, filling the pores of the porous layer 7, can reach the surface of the electron transport layer 3. Therefore, the photoelectric conversion layer 4 is in direct contact with the electron transport layer 3, enabling electron transfer and acceptance.

[0128] By providing a porous layer 7, the photoelectric conversion layer 4 can be easily formed. With the porous layer 7, the material of the photoelectric conversion layer 4 penetrates the pores of the porous layer 7, making the porous layer 7 the foundation of the photoelectric conversion layer 4. Therefore, it is difficult for the material of the photoelectric conversion layer 4 to become incompatible or aggregate on the surface of the porous layer 7. Thus, the photoelectric conversion layer 4 can be easily formed into a uniform film. The photoelectric conversion layer 4 can be formed, for example, by coating, printing, or vapor deposition.

[0129] Light scattering occurs through the porous layer 7, which can also be expected to increase the optical path length of light passing through the photoelectric conversion layer 4. If the optical path length increases, an increase in the amount of electrons and holes generated in the photoelectric conversion layer 4 can be predicted.

[0130] (Technical effects of photoelectric conversion elements) Next, the basic operating effect of the photoelectric conversion element 100 will be explained. In the photoelectric conversion element 100, at least one of the substrate 1 and the second electrode 6 is transparent. Light enters the photoelectric conversion element 100 from the transparent surface. When light shines on the photoelectric conversion element 100, the photoelectric conversion layer 4 absorbs the light, generating excited electrons and holes. The excited electrons move to the electron transport layer 3. On the other hand, the holes generated in the photoelectric conversion layer 4 move to the hole transport layer 5. The electron transport layer 3 and the hole transport layer 5 are electrically connected to the first electrode 2 and the second electrode 6, respectively. Current is drawn from the first electrode 2 and the second electrode 6, which function as negative and positive electrodes, respectively. Furthermore, the hole transport layer 5 and the electron transport layer 3 may sometimes be opposite to each other with respect to the incident direction of light. The photoelectric conversion element 200 of the first modification and the photoelectric conversion element 300 of the second modification also have the same operating effect.

[0131] [Other Implementation Methods] (Postscript) Based on the above description of the embodiments, the following technology is disclosed.

[0132] (Technology 1) A hole transporter comprising: Organic semiconductors, and Nonionic surfactants with a critical micelle concentration in pure water of ≥0.001 g / L and ≤0.080 g / L.

[0133] According to this configuration, the hole transporter of Technology 1 can improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0134] (Technology 2) The hole transporter according to Technology 1, wherein the hole transporter further comprises a dopant.

[0135] According to this configuration, the hole transporter of technology 2 can improve hole transport capability.

[0136] (Technology 3) The hole transporter according to Technology 1 or 2, wherein the nonionic surfactant comprises an alkylhexyl ether having 1 or more and 5 or fewer carbon atoms in the alkyl group.

[0137] Based on this configuration, the hole transporter of technology 3 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0138] (Technology 4) The hole transporter according to Technology 3, wherein the alkylhexyl ether comprises at least one selected from methylhexyl ether, ethylhexyl ether, n-propylhexyl ether, n-butylhexyl ether and n-pentylhexyl ether.

[0139] Based on this configuration, the hole transporter of technology 4 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0140] (Technology 5) A hole transporter according to any one of Technologies 1 to 4, wherein the nonionic surfactant comprises an ester compound obtained by the condensation reaction of a sugar alcohol or an intramolecular dehydration condensation product of a sugar alcohol with a fatty acid.

[0141] Based on this configuration, the hole transporter of technology 5 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0142] (Technology 6) The hole transporter according to Technology 5, wherein the ester compound comprises a fatty acid ester in which the alkyl group has 12 or more and 15 or fewer carbon atoms.

[0143] Based on this configuration, the hole transporter of technology 6 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0144] (Technology 7) The hole transporter according to Technology 5 or 6, wherein the ester compound comprises a glycerol fatty acid ester.

[0145] Based on this configuration, the hole transporter of technology 7 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0146] (Technology 8) A hole transporter according to any one of Technologies 5 to 7, wherein the ester compound comprises a sorbitan fatty acid ester.

[0147] Based on this configuration, the hole transporter of technology 8 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0148] (Technology 9) The hole transporter according to Technology 8, wherein the ester compound comprises glycerol monolaurate.

[0149] Based on this configuration, the hole transporter of technology 9 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0150] (Technology 10) A hole transporter according to any one of Technologies 5 to 9, wherein the ester compound comprises a sugar alcohol fatty acid ester modified with polyethylene glycol.

[0151] According to this configuration, the hole transporter of technology 10 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0152] (Technology 11) The hole transporter according to Technology 10, wherein the polyethylene glycol comprises one or more but less than 22 ethylene glycol units as constituent monomer units.

[0153] According to this configuration, the hole transporter of technology 11 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0154] (Technology 12) The hole transporter according to Technology 10 or 11, wherein the fatty acid ester of the intramolecular dehydration condensation product of the polyethylene glycol-modified sugar alcohol comprises monolaurate.

[0155] According to this configuration, the hole transporter of technology 12 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0156] (Technology 13) The hole transporter according to any one of Technologies 10 to 12, wherein the fatty acid ester of the intramolecular dehydration condensation product of the polyethylene glycol-modified sugar alcohol comprises a monooleate.

[0157] According to this configuration, the hole transporter of technology 13 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0158] (Technology 14) A hole transporter according to any one of Technologies 1 to 13, wherein the nonionic surfactant comprises a copolymer of polyethylene glycol and polypropylene glycol.

[0159] According to this configuration, the hole transporter of technology 14 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0160] (Technology 15) The hole transporter according to Technology 14, wherein the copolymer comprises 6 or more and 53 or less ethylene glycol and 42 or more and 69 or less propylene glycol as constituent monomer units.

[0161] According to this configuration, the hole transporter of technology 15 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0162] (Technology 16) The hole transporter according to any one of Technologies 1 to 15, wherein the nonionic surfactant comprises a glucosinolate derivative.

[0163] According to this configuration, the hole transporter of technology 16 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0164] (Technology 17) The hole transporter according to Technology 16, wherein the glucosinolate derivative is an alkyl glucosinolate derivative.

[0165] According to this configuration, the hole transporter of technology 17 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0166] (Technology 18) The hole transporter according to Technology 17, wherein the alkyl glucoside derivative is n-octyl-α-D-glucopyranoside.

[0167] According to this configuration, the hole transporter of technology 18 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0168] (Technology 19) A hole transporter according to any one of Technologies 1 to 18, wherein the organic semiconductor comprises at least one selected from 2,2',7,7'-tetratetra[N,N-di-p-methoxyphenylamino]-9,9'-spirodifluorene, poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine], poly(3-hexylthiophene-2,5-diyl), poly(3,4-ethylenedioxythiophene), copper phthalocyanine, derivatives of 2,2',7,7'-tetratetra[N,N-di-p-methoxyphenylamino]-9,9'-spirodifluorene, derivatives of poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine], derivatives of poly(3-hexylthiophene-2,5-diyl), derivatives of poly(3,4-ethylenedioxythiophene), and derivatives of copper phthalocyanine.

[0169] According to this configuration, the hole transporter of technology 19 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0170] (Technology 20) The hole transporter according to Technology 2, wherein the dopant comprises at least one selected from lithium hexafluorophosphate, lithium fluoroborate, lithium perchlorate, lithium bis(pentafluoroethanesulfonyl)imide, bis(trifluoromethanesulfonyl)amine, lithium bis(trifluoromethanesulfonyl)imide, zinc bis(trifluoromethanesulfonyl)imide, tri[2-(1H-pyrazol-1-yl)-4-tert-butylpyridine]cobalt, 4-isopropyl-4-methyldiphenyliodonium tetra(pentafluorophenyl)borate, tri(pentafluorophenyl)borane, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethane, and 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecylfluoro-29H,31H-phthalocyanine.

[0171] According to this configuration, the hole transporter of technology 20 can further improve hole transport capability.

[0172] (Technology 21) The hole transporter according to any one of Technologies 1 to 20, wherein the nonionic surfactant is present in an amount of 0.5% by mass or more and 36% by mass or less.

[0173] According to this configuration, the hole transporter of technology 21 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0174] (Technology 22) A hole transporter, comprising: Organic semiconductors, and Nonionic surfactants; The nonionic surfactant comprises alkylhexyl ethers with an alkyl group having 1 or more but less than 5 carbon atoms.

[0175] According to this configuration, the hole transporter of technology 22 can improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0176] (Technology 23) The hole transporter according to Technology 22, wherein the alkylhexyl ether comprises at least one selected from methylhexyl ether, ethylhexyl ether, n-propylhexyl ether, n-butylhexyl ether and n-pentylhexyl ether.

[0177] According to this configuration, the hole transporter of technology 23 can further improve the photoelectric conversion efficiency of the photoelectric conversion material.

[0178] (Technology 24) A photoelectric conversion element comprising a first electrode, a hole transport layer, a photoelectric conversion layer, and a second electrode. The hole transport layer comprises any one of the techniques 1 to 23.

[0179] According to this configuration, the photoelectric conversion element of technology 24 has a high photoelectric conversion efficiency.

[0180] (Technology 25) The photoelectric conversion element according to Technology 24, wherein the photoelectric conversion layer comprises a perovskite-type compound.

[0181] According to this configuration, the photoelectric conversion element of technology 25 has a high photoelectric conversion efficiency.

[0182] (Technology 26) The photoelectric conversion element according to Technology 25, wherein, The perovskite-type compound is composed of a monovalent cation, a divalent cation, and a halide anion. The divalent cation comprises at least one selected from Sn cation, Ge cation and Pb cation.

[0183] According to this configuration, the photoelectric conversion element of technology 24 has a high photoelectric conversion efficiency.

[0184] (Technology 27) A hole transport mechanism composition comprising: Organic semiconductors Nonionic surfactants with a critical micelle concentration in pure water of ≥0.001 g / L and ≤0.080 g / L, and Solvent.

[0185] According to this configuration, if the composition of technique 27 is used, a hole transporter capable of improving the photoelectric conversion efficiency of the photoelectric conversion element can be manufactured.

[0186] (Technology 28) The composition according to Technology 27, wherein the nonionic surfactant in the composition is present in a concentration of more than 0 mg / L and less than 1 mg / L.

[0187] According to this configuration, if the composition of technique 28 is used, a hole transporter capable of improving the photoelectric conversion efficiency of the photoelectric conversion element can be manufactured.

[0188] (Technology 29) The composition according to Technology 27 or 28, wherein the contact angle of the composition with respect to the surface of glass subjected to UV ozone treatment at 24°C is 7° or more and 30° or less.

[0189] According to this configuration, if the composition of technique 29 is used, a hole transporter capable of improving the photoelectric conversion efficiency of the photoelectric conversion element can be manufactured.

[0190] (Technology 30) A hole transport mechanism composition comprising: Organic semiconductors Nonionic surfactants, and Solvent; The nonionic surfactant comprises alkylhexyl ethers with an alkyl group having 1 or more but less than 5 carbon atoms.

[0191] According to this configuration, if the composition of technique 30 is used, a hole transporter capable of improving the photoelectric conversion efficiency of the photoelectric conversion element can be manufactured.

[0192] (Technology 31) The hole transport mechanism composition according to Technology 30, wherein the alkylhexyl ether comprises at least one selected from methylhexyl ether, ethylhexyl ether, n-propylhexyl ether, n-butylhexyl ether and n-pentylhexyl ether.

[0193] According to this configuration, if the composition of technique 31 is used, a hole transporter that can further improve the photoelectric conversion efficiency of the photoelectric conversion element can be manufactured.

[0194] Example The present disclosure will now be described in more detail with reference to embodiments and comparative examples.

[0195] In the embodiments and comparative examples, solar cells comprising a hole transport layer formed of an organic semiconductor film and a photoelectric conversion layer containing a perovskite-type compound were fabricated as photoelectric conversion elements. Initial characteristic evaluation, light durability evaluation, and thermal durability evaluation of the solar cells of the embodiments and comparative examples were performed.

[0196] The configurations of the solar cells of Examples 1 to 7 and Comparative Examples 1 to 2 are described below. In other words, solar cells with the same characteristics as those of Examples 1 to 7 were fabricated. Figure 2 The solar cell with the same structure as the photoelectric conversion element 200 shown is shown.

[0197] • Substrate 1: Glass substrate (thickness: 0.7mm) • Electrode 2: Transparent conductive indium-tin composite oxide layer (thickness: 100nm) Electron transport layer 3: Tin oxide (SnO2) (thickness: 30nm) • Photoelectric conversion layer 4: mainly contains Rb 0.03 Cs 0.06 MA 0.16 FA 0.75 PbI 2.85 Br 0.15 The layer (thickness: 400nm) (MA: CH3NH3, FA: HC(NH2)2) Hole transport layer 5: mainly contains PTAA (with lithium bis(trifluoromethanesulfonyl)imide (manufactured by Tokyo Chemical Industry) as a dopant) (thickness: 60nm) • Second hole transport layer 8: Molybdenum oxide (thickness: 5nm) • Second electrode 6: Indium-tin composite oxide layer (thickness: 100nm) <The Making of Solar Cells> (Example 1) First, prepare a glass substrate with a thickness of 0.7 mm.

[0198] On this substrate, a 100 nm thick layer of indium-tin composite oxide is formed by sputtering. This forms the first electrode.

[0199] Next, a SnO2 nano-dispersed aqueous solution (made by Alfa Aesar) was spin-coated onto the first electrode, then calcined at 220°C for 30 minutes, followed by UV ozone treatment to form a 30 nm thick tin oxide layer. This forms the electron transport layer.

[0200] Next, a photoelectric conversion material solution was spin-coated to form a photoelectric conversion layer containing a perovskite-type compound. This raw material solution contained 1.19 mol / L lead(II) iodide (manufactured by Tokyo Chemical Industry), 0.06 mol / L lead(II) bromide (manufactured by Tokyo Chemical Industry), 0.95 mol / L formamidinium iodide (manufactured by Great Cell Solar), 0.14 mol / L methylammonium iodide (manufactured by Great Cell Solar), 0.06 mol / L methylammonium bromide (manufactured by Great Cell Solar), 0.08 mol / L cesium iodide (manufactured by Iwatani Sangyo), and 0.04 mol / L rubidium iodide (manufactured by Iwatani Sangyo). The solvent for this solution was a mixture of dimethyl sulfoxide (manufactured by Acros) and N,N-dimethylformamide (manufactured by Acros). The mixing ratio of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) in the raw material solution (DMSO:DMF) is 1:4 by volume. After the raw material solution is dropped onto the surface of the electron transport layer, toluene is added dropwise at 2500 rpm for 50 seconds while rotating, thereby preparing a perovskite intermediate film. Then, by heating on a hot plate at 170°C for 10 minutes, a perovskite film is formed from the intermediate film, resulting in a photoelectric conversion layer with a thickness of approximately 400 nm.

[0201] Next, the hole transport mechanism composition of the example was coated onto the photoelectric conversion layer using a spin-coating method, thereby forming a hole transport layer. The solvent in the hole transport mechanism composition was a mixture of 98% mesitylene (manufactured by Kanto Chemical) and 1% tert-butylpyridine by volume. The hole transport mechanism composition contained 10 g / L of PTAA as an organic semiconductor and 40 mol% of lithium bis(trifluoromethanesulfonyl)imide as a dopant, based on the mass of the repeating unit relative to the mass of PTAA. As a nonionic surfactant, three compositions with different concentrations of 1-methoxyhexane-1-propoxyhexane (SA-9, manufactured by Merck) were prepared as the hole transport mechanism composition. Specifically, compositions containing 0.2 g / L, 0.4 g / L, and 0.8 g / L of 1-methoxyhexane-1-propoxyhexane were prepared. Furthermore, Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism composition. The prepared composition was filtered through a 0.2 μm PTFE filter and used to form the hole transport layer. The solution was coated onto the photoelectric conversion layer, rotated at 1000 rpm for 3 seconds and then stopped. The solvent was evaporated using a hot plate at 60°C, followed by drying with a hot plate at 80°C for 10 minutes to obtain a hole transport layer with a thickness of approximately 60 nm.

[0202] Next, a 5 nm molybdenum oxide film was deposited on the hole transport layer by vacuum evaporation, thereby forming the second hole transport layer.

[0203] Next, an indium-tin composite oxide layer with a thickness of 100 nm is formed by sputtering. This forms the second electrode.

[0204] As described above, the solar cell of Example 1 is obtained.

[0205] (Example 2) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to glycerol monolaurate (manufactured by Merck). Two compositions were prepared as hole transport mechanism compositions, with concentrations of 0.2 g / L and 0.4 g / L of glycerol monolaurate (manufactured by Merck). Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0206] (Example 3) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to sorbitan monolaurate (manufactured by Merck). Two compositions were prepared as hole transport mechanism compositions, with concentrations of sorbitan monolaurate (manufactured by Merck) of 0.2 g / L and 0.4 g / L. Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0207] (Example 4) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene sorbitan monolaurate (Tween 20, manufactured by Merck). Three compositions with concentrations of 0.2 g / L, 0.4 g / L, and 0.8 g / L of polyoxyethylene sorbitan monolaurate (Tween 20, manufactured by Merck) were prepared as hole transport mechanism compositions. Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0208] (Example 5) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene sorbitan monooleate (Tween 80, manufactured by Merck). Two compositions with concentrations of 0.2 g / L and 0.4 g / L of polyoxyethylene sorbitan monooleate (Tween 80, manufactured by Merck) were prepared as the hole transport mechanism composition. Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism composition. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0209] (Example 6) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to ethylene oxide-propylene oxide copolymer (PEO5-PPO68-PEO5, Pluronic L 121, manufactured by Merck). Two compositions with concentrations of 0.4 g / L and 0.8 g / L of the ethylene oxide-propylene oxide copolymer (PEO5-PPO68-PEO5, Pluronic L 121, manufactured by Merck) were prepared as the hole transport mechanism composition. Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism composition. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0210] (Example 7) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to n-octyl-α-D-glucopyranoside (α-APG8, manufactured by Merck). A composition with a concentration of 0.8 g / L of n-octyl-α-D-glucopyranoside (α-APG8, manufactured by Merck) was prepared as the hole transport mechanism composition. Table 1 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism composition. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0211] (Example 8) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene sorbitan monolaurate (Tween 20, manufactured by Merck). Three compositions with concentrations of 0.05 g / L, 0.1 g / L, and 0.2 g / L of polyoxyethylene sorbitan monolaurate (Tween 20, manufactured by Merck) were prepared as hole transport mechanism compositions. Table 2 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1. Except for changing the hole transport mechanism composition, changing the material of the second electrode from indium-tin composite oxide to gold (Au), using molybdenum oxide without a second hole transport layer, and performing surface treatment by spin-coating a solution of isopropanol containing 1 g / L butylamine bromide at 4000 rpm after forming the photoelectric conversion layer, a solar cell was fabricated using the same method as in Example 1.

[0212] (Example 9) The nonionic surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene sorbitan monooleate (Tween 80, manufactured by Merck). Four compositions with concentrations of polyoxyethylene sorbitan monooleate (Tween 80, manufactured by Merck) of 0.05 g / L, 0.1 g / L, 0.2 g / L, and 0.4 g / L were prepared as hole transport mechanism compositions. Table 2 also shows the content ratio (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism compositions were prepared in the same manner as in Example 1. Except for changing the hole transport mechanism composition, changing the material of the second electrode from indium-tin composite oxide to gold (Au), using molybdenum oxide without forming the second hole transport layer, and performing surface treatment by spin coating at 4000 rpm with an isopropanol solution containing 1 g / L butylamine bromide, the solar cell was fabricated using the same method as in Example 1.

[0213] (Comparative Example 1) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to a nonionic surfactant, n-hexadecyl β-D-maltose (Merck), with a critical micelle concentration of less than 0.001 g / L. Three compositions with concentrations of n-hexadecyl β-D-maltose of 0.4 g / L, 0.8 g / L, and 1.6 g / L were prepared as hole transport mechanism compositions. Table 1 also shows the percentage (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism compositions were prepared in the same manner as in Example 1, and solar cells were fabricated using the same method as in Example 1.

[0214] (Comparative Example 2) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to dodecyltrimethylammonium bromide (manufactured by Merck), a cationic surfactant. Three compositions were prepared as hole transport mechanism compositions with concentrations of 0.4 g / L, 0.8 g / L, and 1.6 g / L of dodecyltrimethylammonium bromide (manufactured by Merck). Table 1 also shows the proportion (mass %) of the nonionic surfactant in the hole transport mechanism compositions. Otherwise, the hole transport mechanism compositions were prepared in the same manner as in Example 1, and solar cells were fabricated using the same method as in Example 1.

[0215] (Comparative Example 3) No 1-methoxyhexane-1-propoxyhexane was added to the hole transport mechanism composition. That is, the hole transport mechanism composition of Comparative Example 3 does not contain a surfactant. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 1, and a solar cell was fabricated using the same method as in Example 1.

[0216] (Comparative Example 4) Polyoxyethylene sorbitan monolaurate (Tween 20, manufactured by Merck) was not added to the hole transport mechanism composition. In other words, the hole transport mechanism composition of Comparative Example 4 does not contain a surfactant. Otherwise, the hole transport mechanism composition was prepared in the same manner as in Example 8, and a solar cell was fabricated using the same method as in Example 8.

[0217] (Comparative Example 5) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to sodium dodecyl sulfate (manufactured by Merck), an anionic surfactant. A composition with a sodium dodecyl sulfate (manufactured by Merck) concentration of 0.8 mg / L was prepared as the hole transport mechanism composition. However, sodium dodecyl sulfate did not dissolve in the raw material solution. Therefore, a hole transporter could not be produced in Comparative Example 5, and a solar cell could not be produced either. Furthermore, the critical micelle concentration of sodium dodecyl sulfate was 2.384 g / L.

[0218] (Comparative Example 6) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to N-dodecyl-N,N-dimethyl-3-ammonium-1-propanesulfonate, an amphoteric surfactant. A composition with a concentration of 0.8 mg / L of N-dodecyl-N,N-dimethyl-3-ammonium-1-propanesulfonate was prepared as the hole transport mechanism composition. However, N-dodecyl-N,N-dimethyl-3-ammonium-1-propanesulfonate was not dissolved in the raw material solution. Therefore, a hole transporter could not be produced in Comparative Example 6, and a solar cell could not be produced either. Furthermore, the critical micelle concentration of sodium dodecyl sulfate was 1.107 g / L.

[0219] (Comparative Example 7) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to an ethylene oxide-propylene oxide copolymer (PEO95-PPO62-PEO95, Pluronic L 127, manufactured by Merck) as a nonionic surfactant. A composition with a concentration of 0.8 mg / L of the ethylene oxide-propylene oxide copolymer (PEO95-PPO62-PEO95, Pluronic L 127, manufactured by Merck) was prepared as the hole transport mechanism composition. However, this composition is hydrophobic and therefore cannot be used to produce a hole transporter. Therefore, a solar cell was not produced in Comparative Example 7. Furthermore, the critical micelle concentration of the ethylene oxide-propylene oxide copolymer (PEO95-PPO62-PEO95, Pluronic L 127, manufactured by Merck) was 50.000 g / L.

[0220] (Comparative Example 8) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene octylphenyl ether, a nonionic surfactant. A composition with a polyoxyethylene octylphenyl ether concentration of 0.8 mg / L was prepared as the hole transport mechanism composition. However, the polyoxyethylene octylphenyl ether did not dissolve in the raw material solution. Therefore, a hole transporter could not be produced in Comparative Example 8, and a solar cell was not produced either. Furthermore, the critical micelle concentration of polyoxyethylene octylphenyl ether was 0.150 g / L.

[0221] (Comparative Example 9) The surfactant in the hole transport mechanism composition was changed from 1-methoxyhexane-1-propoxyhexane to polyoxyethylene lauryl ether as a nonionic surfactant. A composition with a polyoxyethylene lauryl ether concentration of 0.8 mg / L was prepared as the hole transport mechanism composition. However, the polyoxyethylene lauryl ether did not dissolve in the raw material solution. Therefore, a hole transporter could not be produced in Comparative Example 9, nor could a solar cell be produced. Furthermore, the critical micelle concentration of the polyoxyethylene lauryl ether was 0.123 g / L.

[0222] <Determination of the critical micelle concentration of surfactants> The critical micelle concentrations of the surfactants used in the examples and comparative examples were determined using the following method. Solutions containing the surfactants were prepared in pure water, and the dependence of surface tension on concentration was investigated using the Wilhelmy plate method with these solutions. The concentration of the surfactant at which the surface tension remained unchanged was taken as the critical micelle concentration. The results are shown in Table 1. Furthermore, in Table 1, the critical micelle concentration is recorded as "CMC".

[0223] <Determination of the contact angle of the composition acting on the hole transport mechanism> A glass substrate was subjected to UV ozone treatment. A composition was then dropped onto the surface of the substrate using a micropipette. The droplets were observed and recorded using a CCD camera, and the contact angle was measured accordingly. The contact angle was measured using FAMAS (manufactured by Kyowa Interface Science Co., Ltd.). The results are shown in Table 1. In Table 1, the contact angle is recorded as "CA".

[0224] <Evaluation of Solar Cells> The current-voltage characteristics of the solar cells of Examples 1 to 9 and Comparative Examples 1 to 4 were measured in an inert atmosphere.

[0225] The current and voltage characteristics of the solar cell were measured using an electrochemical analyzer (ALS440B, BAS) and a xenon light source (BPS X300BA, spectrophotometer). Prior to measurement, the light intensity was calibrated to 1 Sun (100 mW / cm²) using a silicon photodiode. 2 The voltage scan rate was 100 mV / s. Before the measurement began, the area was exposed to indoor light for approximately one hour to allow for stabilization. To fix the effective area and reduce the influence of scattered light, an opening of 0.1 cm was used. 2 With the solar cells shielded by a black mask, light was irradiated from the mask / substrate side. Using this method, the current-voltage characteristics of the solar cells in the examples and comparative examples were measured, and the power conversion efficiency (PCE) was determined.

[0226] The current and voltage characteristics of the solar cells in Examples 1 to 7 and Comparative Examples 1 to 3 were measured at the initial stage, after the light endurance test, and after the light endurance-heat endurance test. The initial stage refers to the measurement performed immediately after fabrication. The light endurance test refers to the measurement after irradiation at a substrate surface temperature of 50°C for 1 day and 135 hours. The light endurance-heat endurance test refers to the measurement after irradiation at a substrate surface temperature of 50°C for 1 day and 135 hours, followed by heating in the dark at 85°C for 66 hours, and then irradiation for 1 day and 23 hours. The current and voltage characteristics of the solar cells in Examples 8, 9, and Comparative Example 4 were measured only at the initial stage.

[0227] Tables 1 and 2 show the photoelectric conversion efficiency (PCE) results of the solar cells of the embodiments and comparative examples. Tables 1 and 2 also show the open-circuit voltage (V). oc ), short-circuit current density (J SC ) and fill factor (FF).

[0228] <Comparison of photoelectric conversion efficiency> In the hole transport layer of the solar cells of Examples 1 to 7, a nonionic surfactant with a critical micelle concentration of 0.001 g / L or more and 0.080 g / L or less was added. Regarding the light resistance and heat resistance of the solar cells of Examples 1 to 7 during actual power generation, the following effects were confirmed: the open-circuit voltage (Voc) and fill factor (FF) were improved, resulting in an improvement in photoelectric conversion efficiency (PCE).

[0229] On the other hand, when a nonionic surfactant with a critical micelle concentration of less than 0.001 g / L was added to the hole transport layer, as in Comparative Example 1, all characteristic parameters decreased, resulting in a decrease in photoelectric conversion efficiency. Furthermore, when a cationic surfactant was added, as in Comparative Example 2, all characteristic parameters decreased, photoelectric conversion efficiency decreased, and no performance improvement was observed. This can be attributed to the fact that when the surfactant is cationic, the interaction with the dopant molecules becomes too strong, which can reduce the contact angle but hinders the doping function.

[0230] Comparing the photoelectric conversion efficiencies of the solar cells of Examples 8, 9, and Comparative Example 4, which are identical in all components except for the hole transport layer, it can be seen that the solar cells of Examples 8 and 9, which have a hole transport layer containing a nonionic surfactant with a critical micelle concentration of 0.001 g / L or more and 0.080 g / L or less, have higher conversion efficiencies than the solar cell of Comparative Example 4, which has a hole transport layer without a nonionic surfactant.

[0231] <The Effects of Surfactants> As described above, the examples and comparative examples demonstrate that there exists an appropriate critical micelle concentration in nonionic surfactants. When the critical micelle concentration is too high, the excessive hydrophilicity prevents it from dissolving in the solvent (in this case, a nonpolar solvent) of the composition used to fabricate the hole transport layer. Conversely, when the critical micelle concentration of the nonionic surfactant is too low, it dissolves well due to excessive lipophilicity, but the photoelectric conversion efficiency decreases. This can be attributed to the fact that the nonionic surfactant hinders the dispersion of polar molecules, which are dopant materials, thus hindering the formation of a homogeneous hole transport layer.

[0232] Industrial availability This disclosure improves the photoelectric conversion efficiency of photoelectric conversion elements by using hole transporters containing specific nonionic surfactants. Therefore, the hole transporters of this disclosure can be used in photoelectric conversion elements such as solar cells.

Claims

1. A hole transporting body comprising: an organic semiconductor, and a nonionic surfactant having a critical micelle concentration of 0.001 g / L or more and 0.080 g / L or less in pure water.

2. The hole transport body of claim 1, wherein, The hole transporting body further comprises a dopant.

3. The hole transporter of claim 1 or 2, wherein, The nonionic surfactant comprises an alkyl hexyl ether having 1 or more and 5 or less carbon atoms in an alkyl group.

4. The hole transport body of claim 3, wherein, The alkyl hexyl ether comprises at least one selected from the group consisting of methyl hexyl ether, ethyl hexyl ether, n-propyl hexyl ether, n-butyl hexyl ether, and n-pentyl hexyl ether.

5. The hole transporter according to any one of claims 1 to 4, wherein, The nonionic surfactant comprises an ester compound obtained by condensation reaction of a sugar alcohol or an intramolecular dehydration condensation product of a sugar alcohol with a fatty acid.

6. The hole transport body of claim 5, wherein, The ester compound comprises a fatty acid ester having 12 or more and 15 or less carbon atoms in an alkyl group.

7. The hole-transport body according to claim 5 or 6, wherein, The ester compound comprises a glycerin fatty acid ester.

8. The hole transporter according to any one of claims 5 to 7, wherein, The ester compound comprises a sorbitan fatty acid ester.

9. The hole transporter according to any one of claims 5 to 8, wherein, The ester compound comprises glycerin monolaurate.

10. The hole transporter according to any one of claims 5 to 9, wherein, The ester compound comprises a fatty acid ester of an intramolecular dehydration condensation product of a sugar alcohol modified with polyethylene glycol.

11. The hole transport body of claim 10, wherein, The polyethylene glycol comprises 1 or more and 22 or less ethylene glycol as a constituting monomer unit.

12. The hole-transport body of claim 10 or 11, wherein, The fatty acid ester of the intramolecular dehydration condensation product of a sugar alcohol modified with polyethylene glycol comprises a monolaurate ester.

13. The hole transporter according to any one of claims 10 to 12, wherein, The fatty acid ester of the intramolecular dehydration condensation product of a sugar alcohol modified with polyethylene glycol comprises a monooleate ester.

14. The hole transporter according to any one of claims 1 to 13, wherein, The nonionic surfactant comprises a copolymer of polyethylene glycol and polypropylene glycol.

15. The hole transport body of claim 14, wherein, The copolymer comprises 6 or more and 53 or less ethylene glycol and 42 or more and 69 or less propylene glycol as constituting monomer units.

16. The hole transporter according to any one of claims 1 to 15, wherein, The nonionic surfactant comprises a glucoside derivative.

17. The hole transport body of claim 16, wherein, The glucoside derivative is an alkyl glucoside derivative.

18. The hole transport body of claim 17, wherein, The alkyl glucoside derivative is n-octyl-α-D-glucopyranoside.

19. The hole transporter according to any one of claims 1 to 18, wherein, The organic semiconductor comprises at least one selected from the group consisting of 2,2',7,7'-tetrakis[N,N-di-p-methoxyphenylamino]-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine], poly(3-hexylthiophene-2,5-diyl), poly(3,4-ethylenedioxythiophene), copper phthalocyanine, a derivative of 2,2',7,7'-tetrakis[N,N-di-p-methoxyphenylamino]-9,9'-spirobifluorene, a derivative of poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine], a derivative of poly(3-hexylthiophene-2,5-diyl), a derivative of poly(3,4-ethylenedioxythiophene), and a derivative of copper phthalocyanine.

20. The hole transport body of claim 2, wherein, The dopant includes at least one selected from the group consisting of lithium hexafluorophosphate, lithium fluoroborate, lithium perchlorate, lithium bis(pentafluoroethanesulfonyl)imide, bis(trifluoromethylsulfonyl)amide, lithium bis(trifluoromethylsulfonyl)imide, zinc bis(trifluoromethylsulfonyl)imide, tris[2-(1H-pyrazol-1-yl)-4-tert-butylpyridine]cobalt, 4-isopropyl-4-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)borane, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane, and 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine.

21. The hole transporter of any one of claims 1-20, wherein, The nonionic surfactant is contained in a proportion of 0.5% by mass or more and 36% by mass or less.

22. A hole-transporter comprising: an organic semiconductor, and a nonionic surfactant; the nonionic surfactant includes an alkyl hexyl ether having a number of carbon atoms of an alkyl group of 1 or more and 5 or less.

23. The hole transport body of claim 22, wherein, the alkyl hexyl ether includes at least one selected from the group consisting of a methyl hexyl ether, an ethyl hexyl ether, a n-propyl hexyl ether, a n-butyl hexyl ether, and a n-pentyl hexyl ether.

24. A photoelectric conversion element comprising a first electrode, a hole-transport layer, a photoelectric conversion layer, and a second electrode, the hole-transport layer includes the hole-transporter according to any one of claims 1 to 23.

25. The photoelectric conversion element according to claim 24, wherein the photoelectric conversion layer includes a perovskite compound.

26. The photoelectric conversion element according to claim 25, wherein the perovskite compound is composed of a monovalent cation, a divalent cation, and a halide anion, the divalent cation includes at least one selected from the group consisting of a Sn cation, a Ge cation, and a Pb cation.

27. A hole-transporter preparation composition comprising: an organic semiconductor; a nonionic surfactant having a critical micelle concentration of 0.001 g / L or more and 0.080 g / L or less in pure water; and a solvent.

28. The composition of claim 27, wherein, The nonionic surfactant in the composition is contained in a proportion of more than 0 g / L and 1 g / L or less.

29. The composition of claim 27 or 28, wherein, The composition has a contact angle of 7° or more and 30° or less with respect to a surface of a glass subjected to UV ozone treatment at 24°C.

30. A hole-transporter preparation composition comprising: an organic semiconductor; a nonionic surfactant; and a solvent; the nonionic surfactant includes an alkyl hexyl ether having a number of carbon atoms of an alkyl group of 1 or more and 5 or less.

31. The hole transport body functioning composition according to claim 28, wherein the alkyl hexyl ether includes at least one selected from the group consisting of a methyl hexyl ether, an ethyl hexyl ether, a n-propyl hexyl ether, a n-butyl hexyl ether, and a n-pentyl hexyl ether.

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