Photoelectric conversion element and photoelectric conversion device

Abstract

To provide a photoelectric conversion element that has high initial photoelectric conversion efficiency and improved durability.SOLUTION: The photoelectric conversion element has: a first electrode; a second electrode; and a photoelectric conversion layer containing a perovskite structure crystal. The photoelectric conversion element is characterized in that: with a smaller one of the electrode areas of the first electrode and the second electrode defined to be S[cm2], a maximum value of a resistance Rrec [Ω], which is obtained by fitting an arc corresponding to a maximum value of a phase in a low-frequency range in the Nyquist plot based on impedance measurement results using a parallel circuit of a resistor element and a constant phase element, satisfies the following equation (E1), 1.0×104<Rrec×S<1.0×107 (E1); and the Rrec a maximum and a maximum value Rct [Ω] of the resistance values, which is obtained by fitting an arc corresponding to a maximum value of a phase in a high-frequency range using the parallel circuit of the resistor element and the constant phase element, satisfy the following equation (E2), Rrec / Rct≥25 (E2).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion element and a photoelectric conversion device. [Background technology]

[0002] In order to solve the problem of fossil energy depletion and the global environmental problems caused by the use of fossil energy, active research is being conducted on renewable and clean alternative energy sources such as solar energy, wind power, and hydroelectric power. Among them, interest in solar cells that directly convert sunlight into electrical energy is increasing. Here, a solar cell refers to a cell that generates a current and voltage by utilizing the photovoltaic effect in which light energy from sunlight is absorbed and electrons and holes are generated.

[0003] Currently, np diode type silicon (Si) single crystal-based solar cells with a light energy conversion efficiency of over 20% are widely known and are actually used for photovoltaic power generation. However, these require high-temperature processing and the materials themselves are expensive, so they have the problem of high cost per unit of power. In addition, there are problems with supply in terms of silicon resources.

[0004] On the other hand, solar cells using organic materials (hereinafter referred to as "organic solar cells") do not require high-temperature processing and can be produced using a sheet-like substrate by the so-called roll-to-roll method, which is expected to reduce costs. However, further improvements in power generation efficiency and durability are required for the practical use of organic solar cells. In particular, perovskite-type solar cells, which have crystals with a perovskite structure as a photoelectric conversion layer, have excellent photoelectric conversion characteristics, so development is being promoted for the practical use of solar cells.

[0005] Patent Document 1 describes a technique for improving peeling from an electrode by including an organic semiconductor and a polymer compound having a glass transition temperature of 100° C. or higher in a hole transport layer.

[0006] Patent Document 2 describes a configuration in which a layer made of a quinacridone pigment is provided between a perovskite layer and a hole transport layer, and the results of impedance measurements of this configuration.

[0007] Non-Patent Document 1 describes a technology for a charge transport layer for a reverse layer in which photoelectric conversion efficiency is improved by doping PEDOT:PSS with nickel phthalocyanine having a substituent. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2018-170382 A [Patent Document 2] US Patent Application Publication No. 2022 / 0285642 [Non-patent literature]

[0009] [Non-Patent Document 1] X.-F. Zhang,J. Mater. Chem. A,2018,6, 12515-12522 Summary of the Invention [Problem to be solved by the invention]

[0010] According to the studies of the present inventors, it has been found that the photoelectric conversion elements described in Patent Document 1, Patent Document 2, and Non-Patent Document 1 have room for improvement in terms of durability.

[0011] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, an object of the present invention is to provide a photoelectric conversion element and a photoelectric conversion device with improved durability. [Means for solving the problem]

[0012] The above object can be achieved by the present invention. That is, the photoelectric conversion element according to the present invention comprises: A photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, The smaller of the electrode areas of the first electrode and the second electrode is defined as S [cm 2 ]year, A DC voltage component V DC =0[V], root mean square of AC voltage component V rms = 50 [mV] AC voltage with frequency 1.0 × 10 -2 [Hz]~1.0×10 6 When the impedance is measured while changing the frequency between [Hz], In a plot based on the impedance measurement results, the horizontal axis is frequency [Hz] and the vertical axis is phase [deg]. 1.0×10 -2 [Hz] or more 1.0×10 2 The phase of the impedance has a maximum value in a low frequency range of less than [Hz], 1.0×10 2 [Hz] or more 1.0×10 6 The phase of the impedance has a maximum value in the high frequency range of Hz or less, In a Nyquist plot based on the impedance measurement results, the horizontal axis is the real part of the impedance Z' [Ω] and the vertical axis is the imaginary part of the impedance Z'' [Ω]. The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the low frequency range with a parallel circuit of a resistor element and a constant phase element is rec [Ω] satisfies the following formula (E1), 1.0×10 4 ≦R rec ×S≦1.0×10 7 (E1) The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the high frequency range with a parallel circuit of a resistor element and a constant phase element is ct [Ω] and the R rec [Ω] satisfies the following formula (E2); R rec / R ct ≧25 (E2) It is characterized by: Effect of the Invention

[0013] According to the present invention, it is possible to provide a photoelectric conversion element having high initial photoelectric conversion efficiency and improved durability. [Brief description of the drawings]

[0014] [Figure 1] 1 is a plot of impedance data obtained in Example 4 of the present invention, with the horizontal axis representing frequency [Hz] and the vertical axis representing phase [deg]. [Diagram 2] 1 is a Nyquist plot of impedance data and fitting curves obtained in Example 4 of the present invention. [Diagram 3] FIG. 13 is a diagram for explaining the meaning of a circular arc corresponding to a maximum value of a phase in the present invention. [Figure 4] 1 is an equivalent circuit used in fitting in impedance analysis in an embodiment of the present invention. [Diagram 5] 1 is a schematic cross-sectional view in a thickness direction of a first embodiment of a photoelectric conversion element of the present invention. [Figure 6] 1 is a perspective view showing a schematic diagram of an embodiment of a moving body including a photoelectric conversion element of the present invention; [Figure 7] FIG. 1 is a perspective view illustrating a schematic diagram of one embodiment of a building material including a photoelectric conversion element of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The photoelectric conversion element of the present invention is a photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, The smaller of the electrode areas of the first electrode and the second electrode is defined as S [cm 2 ]year, A DC voltage component V DC =0[V], root mean square of AC voltage component V rms= 50 [mV] AC voltage with frequency 1.0 × 10 -2 [Hz]~1.0×10 6 When the impedance is measured while changing the frequency between [Hz], In a plot based on the impedance measurement results, the horizontal axis is frequency [Hz] and the vertical axis is phase [deg]. 1.0×10 -2 [Hz] or more 1.0×10 2 The phase of the impedance has a maximum value in a low frequency range of less than [Hz], 1.0×10 2 [Hz] or more 1.0×10 6 The phase of the impedance has a maximum value in the high frequency range of Hz or less, In a Nyquist plot based on the impedance measurement results, the horizontal axis is the real part of the impedance Z' [Ω] and the vertical axis is the imaginary part of the impedance Z'' [Ω]. The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the low frequency range with a parallel circuit of a resistor element and a constant phase element is rec [Ω] satisfies the following formula (E1), 1.0×10 4 ≦R rec ×S≦1.0×10 7 (E1) The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the high frequency range with a parallel circuit of a resistor element and a constant phase element is ct [Ω] and the R rec [Ω] satisfies the following formula (E2); R rec / R ct ≧25 (E2) It is characterized by:

[0016] As a result of investigation, the inventors have found that by satisfying the above-mentioned configuration, it is possible to suppress the deterioration of the photoelectric conversion element during durable use, which is caused by defects in the photoelectric conversion layer. Conventionally, when the resistance of the photoelectric conversion element is increased in order to suppress the deterioration, the movement of the charge generated in the photoelectric conversion layer is hindered, and the initial photoelectric conversion efficiency is deteriorated. In contrast, when the resistance is lowered in order to improve the initial photoelectric conversion efficiency, the effect of suppressing the deterioration is not sufficient.

[0017] Therefore, the inventors have determined that the impedance on the low frequency side is expressed by the following formula (E1): 1.0×10 4 ≦R rec ×S≦1.0×10 7 (E1) When the impedance ratio between the low frequency side and the high frequency side is R rec / R ct It has been found that both the initial photoelectric conversion efficiency and the suppression of deterioration can be achieved if the ratio of the initial photoelectric conversion efficiency to the degradation rate is ≧25. The present inventors speculate that the reason for this is as follows.

[0018] On the other hand, the impedance of the low frequency side, R rec [Ω] means the recombination resistance, which is correlated with the difficulty of recombining electrons and holes generated in the photoelectric conversion layer. If this value is equal to or greater than a certain value, the durability deterioration is suppressed. However, if this value is too large, the initial photoelectric conversion efficiency deteriorates. In order to balance these two, the following formula (E1) is used. 1.0×10 4 ≦R rec ×S≦1.0×10 7 (E1) must be met.

[0019] On the other hand, the impedance of the high frequency side R ct [Ω] means the charge transfer resistance, which correlates with the ease of charge transfer when the photoelectric conversion element performs photoelectric conversion. The smaller this value, the better the initial photoelectric conversion efficiency. Therefore, in order to achieve both the initial photoelectric conversion efficiency and the suppression of deterioration, in addition to the above formula (E1), the following formula (E2) is used: R rec / R ct ≧25 (E2) must be met.

[0020] As described above, by establishing a condition that provides a correlation between impedance characteristic values ​​in different frequency ranges, such as in formula (E2), rather than a range condition for a single impedance characteristic value, such as in formula (E1), or a range condition for each of a plurality of impedance characteristic values, it is possible to essentially solve the conventional difficulty of achieving both high initial photoelectric conversion efficiency and suppression of degradation.

[0021] As explained above, the respective components exert a synergistic effect on each other, thereby making it possible to achieve the effects of the present invention.

[0022] The present invention will be described in detail below with reference to preferred embodiments. The present invention is not limited to the following embodiments, and any modifications or improvements to the following embodiments based on the ordinary knowledge of a person skilled in the art without departing from the spirit of the present invention are also included in the scope of the present invention.

[0023] [Impedance characteristics of the present invention] The photoelectric conversion element of the present invention is a photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, The smaller of the electrode areas of the first electrode and the second electrode is defined as S [cm 2 ]year, A DC voltage component V DC =0[V], root mean square of AC voltage component V rms = 50 [mV] AC voltage with frequency 1.0 × 10 -2 [Hz]~1.0×10 6 When the impedance is measured while changing the frequency between [Hz], In a plot based on the impedance measurement results, the horizontal axis is frequency [Hz] and the vertical axis is phase [deg]. 1.0×10 -2 [Hz] or more 1.0×10 2The phase of the impedance has a maximum value in a low frequency range of less than [Hz], 1.0×10 2 [Hz] or more 1.0×10 6 The phase of the impedance has a maximum value in the high frequency range of Hz or less, In a Nyquist plot based on the impedance measurement results, the horizontal axis is the real part of the impedance Z' [Ω] and the vertical axis is the imaginary part of the impedance Z'' [Ω]. The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the low frequency range with a parallel circuit of a resistor element and a constant phase element is rec [Ω] satisfies the following formula (E1), 1.0×10 4 ≦Rrec×S≦1.0×10 7 (E1) The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the high frequency range with a parallel circuit of a resistor element and a constant phase element is ct [Ω] and the R rec [Ω] satisfies the following formula (E2); R rec / R ct ≧25 (E2) It is characterized by:

[0024] Here, a plot with frequency [Hz] on the horizontal axis and phase [deg] on the vertical axis is a graph that correlates the frequency value of the AC voltage in impedance measurement with the angle on the complex plane formed by the real part Z' and imaginary part Z'' of the impedance obtained when that frequency is applied: arctan(Z'' / Z'), as shown in Figure 1.

[0025] In addition, a Nyquist plot with the horizontal axis being the real part of impedance Z' [Ω] and the vertical axis being the imaginary part of impedance Z'' [Ω] corresponds to a graph in which the real part Z' and imaginary part Z'' of the impedance described above are plotted on a complex plane, as shown in Figure 2.

[0026] However, in the present invention, the positive and negative signs are plotted along the -Z'' axis. Accordingly, in the present invention, the phase [deg] is also plotted along the - (minus) axis. Therefore, the maximum value of the phase in the low frequency range or high frequency range in the present invention refers to the extreme value where the phase increases in the - direction. These issues regarding positive and negative signs depend on the definition of complex impedance Z [Ω] and are not essential issues.

[0027] We will explain what is meant by the arc corresponding to the maximum value of the phase in the low frequency range or the high frequency range. As shown in Figure 3a), if the maximum value in the low frequency range is θlow, this θlow corresponds to the slope of a tangent line passing through the origin to the arc in the low frequency range in the Nyquist plot in Figure 3b. Therefore, the arc corresponding to the maximum value of the phase is exactly the arc with such a tangent line drawn.

[0028] The constant phase element of the present invention will be described. The constant phase element is used in the equivalent circuit when fitting the impedance data shown as an example in FIG. 4, and is indicated by "CPE (1-3)" that appears in the R-CPE parallel circuit in FIG. 4. The constant phase element is an element that is a mathematically modified capacitive element (capacitive element) for fitting. The complex impedance of the capacitive element is expressed by the following formula (E7), while ZC=1 / (i2πfC) (E7) (where i is the imaginary unit, π is the ratio of the circumference of a circle to its diameter, f is frequency [Hz], and C is capacity [F]) The complex impedance of the constant phase element is expressed by the following equation (E8). ZCPE = 1 / [(i2πf)PT] (E8)

[0029] If P=1, then the above formula (E8) coincides with formula (E7) (where T=C), and therefore the constant phase element is indeed a mathematical transformation of a capacitive element. The exponent P of the constant phase element expressed by equation (E8) corresponds to the degree of compression of the arc on the Nyquist plot, and if the arc is a perfect semicircle, P = 1, but if the semicircle sinks into the fourth quadrant on the Nyquist plot, P < 1. The degree of compression of the arc on the Nyquist plot correlates with the variance of the impedance, so the smaller P is than 1, the greater the variance of the impedance.

[0030] In order to enhance the effect of the present invention, R rec ×S [Ω cm 2 ] is expressed by the following formula (E5): 1.0×10 5 <R rec ×S<1.0×10 6 (E5) It is more preferable that:

[0031] Also, R rec / R ct is expressed by the following formula (E6): R rec / R ct ≧50 (E6) It is preferable that:

[0032] In order to suppress deterioration more effectively, the above-mentioned R rec The exponent P of the constant phase element obtained by fitting to obtain [Ω] rec is expressed by the following formula (E3): P rec ≧0.80 (E3) It is preferable to satisfy the formula (E3). When the formula (E3) is satisfied, the variance of the impedance on the low frequency side corresponding to the recombination resistance is sufficiently small. Therefore, the recombination resistance that contributes to concealing defects in the photoelectric conversion layer becomes uniform in the surface direction of the photoelectric conversion layer, and the probability of concealing defects in the photoelectric conversion layer is improved.

[0033] In order to effectively maintain the initial photoelectric conversion efficiency at a high level, ct The exponent P of the constant phase element obtained by fitting to obtain [Ω] ct is expressed by the following formula (E4): Pct ≦0.95 (E4) It is preferable to satisfy the formula (E4). When the formula (E4) is satisfied, the variance of the impedance on the high frequency side corresponding to the charge transfer resistance is sufficiently large. Therefore, since there are sufficient low resistance paths for the transfer of the photocharges generated in the photoelectric conversion layer, a high resistance recombination resistance element that contributes to global defect concealment in the surface direction of the photoelectric conversion layer and a low resistance charge transfer resistance element that contributes to the local charge transfer path of the photoelectric conversion element are further compatible.

[0034] Hereinafter, the photoelectric conversion element of the present invention and the configuration of each layer thereof will be described in detail with reference to preferred embodiments. The following are some examples for obtaining the above-mentioned [impedance characteristics of the present invention]. Therefore, the present invention is not limited to the following embodiments, and the scope of the present invention also includes appropriate modifications and improvements to the following embodiments based on the ordinary knowledge of a person skilled in the art, within the scope of the present invention.

[0035] In this specification, the term "layer" refers not only to a layer having a clear boundary or a flat thin-film layer, but also to a layer having a concentration gradient in which the contained elements change gradually, or to a layer that can form a complex structure together with other layers. Elemental analysis of a layer can be performed, for example, by performing TOF-SIMS / FE-TEM / EDS line analysis measurement of a cross section of a photoelectric conversion element to confirm the element distribution of a specific element. Analysis of each layer may be performed by peeling and removing the layer from a completed photoelectric conversion element, exposing the layer to be analyzed, and measuring it. The volume ratio can also be quantified by using the area ratio of the exposed surface or cross section as the volume ratio of the layer.

[0036] 5 is a cross-sectional view showing a schematic configuration of one embodiment of the photoelectric conversion element of the present invention. A second electrode 3, an electron transport layer 4, a photoelectric conversion layer 5, a charge transport layer 6, and a first electrode 7 are provided on a substrate 2. One of the first electrode 7 and the second electrode 3 is an anode and the other is a cathode, and a current can be extracted by connecting the first electrode 7 and the second electrode 3 to an external circuit.

[0037] The photoelectric conversion layer 5 is excited by light incident through the substrate 2, the second electrode 3, and the electron transport layer 4, or the first electrode 7 and the charge transport layer 6, and generates electrons or holes. That is, the photoelectric conversion layer 5 generates a current between the first electrode 7 and the second electrode 3. The electron transport layer 4 is a layer disposed between the photoelectric conversion layer 5 and the two electrodes 3 and 7, and may not be formed in some cases. A form in which a plurality of electron transport layers 4 and photoelectric conversion layers 5 are laminated may be used. Such a form may also be called a tandem structure. Each member will be described below. In addition, a photoelectric conversion element may be fabricated on the substrate 2 in the order of the first electrode 7, the charge transport layer 6, the photoelectric conversion layer 5, the electron transport layer 4, and the second electrode 3.

[0038] [Photoelectric conversion element] The photoelectric conversion element of the present invention is characterized by having a first electrode, a second electrode, a photoelectric conversion layer containing a crystal of a perovskite structure disposed between the first electrode and the second electrode, and a charge transport layer between the photoelectric conversion layer and the first electrode. In addition, in order to improve the photoelectric conversion efficiency, the photoelectric conversion elements may be stacked in a tandem type. The photoelectric conversion elements to be stacked are not limited to the type of photoelectric conversion element, and may include a perovskite solar cell using a perovskite crystal in the photoelectric conversion layer, a silicon solar cell, a CIGS solar cell, and the like.

[0039] The photoelectric conversion layer of the photoelectric conversion element of the present invention and each layer including the charge transport layer can be formed by coating or vapor deposition. Examples of the coating method include dip coating, spin coating, spray coating, inkjet coating, meniscus coating, screen coating, roll coating, die coating, blade coating, curtain coating, and wire bar coating. The coating method is a method in which the coating liquid for each layer described later is prepared, coated in the desired order, and dried. A desired method can be selected from these film formation methods according to each layer. Each layer will be described below.

[0040] 〔substrate〕 The photoelectric conversion element 1 of the present invention may include a substrate 2, examples of which include a transparent glass substrate such as soda-lime glass or alkali-free glass, a ceramic substrate, a transparent plastic substrate, etc. When light is taken in from the first electrode 7 side, an opaque material can be used for the substrate 2, and when light is taken in from the second electrode 3 side, the substrate 2 is made of a transparent material.

[0041] 〔electrode〕 The photoelectric conversion element of the present invention has a first electrode and a second electrode. The materials of the first electrode 7 and the second electrode 3 are not particularly limited, and conventionally known materials can be used. For example, metals such as gold, silver, titanium, and copper, sodium, sodium-potassium alloy, lithium, magnesium, carbon, carbon nanotubes, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al2O3 mixture, and Al / LiF mixture can be mentioned. Examples of transparent electrode materials include conductive transparent materials such as CuI, ITO (indium tin oxide), SnO2, AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), FTO (fluorine-doped tin oxide), and ATO (antimony-doped tin oxide), conductive transparent polymers, etc. These materials may be used alone, or two or more of them may be used in combination. At least one of the first electrode 7 and the second electrode 3 on the light incident side is a transparent electrode, and the other may be a transparent electrode or may also serve as a reflective layer made of a light-reflective material, or may be a transparent electrode provided with a reflective layer on the side opposite to the light incident side. When the first electrode 7 is on the light incident side, the second electrode 3 may be a transparent electrode and the substrate 2 may be a reflective layer. The electrodes may be patterned electrodes.

[0042] [Photoelectric Conversion Layer] The photoelectric conversion layer 5 has a crystal having a perovskite structure. The crystal having a perovskite structure used in the present invention is preferably represented by the following general formula [1]. ABX3[1] In the above general formula [1], A is a monovalent cation of an organic molecule or a metal atom, B is a divalent metal cation, and X is a monovalent halide anion.

[0043] In the general formula [1], A is preferably represented by, for example, CpNqHr (where p, q, and r are all positive integers) in the case of an organic molecule. Specific examples include methylammonium and formamidium.

[0044] The inorganic atom is not particularly limited, but lithium, cesium, sodium, potassium, and rubidium are preferred. These organic molecules or inorganic atoms may be used alone or in combination of two or more.

[0045] When the constituent A cations are too large to fit within the 3D perovskite crystal, they form 2D perovskite crystals, 2.5D perovskite crystals with both 2D and 3D properties, bilayer crystals of 3D and 2D perovskite structures, or mixed 3D and 2D perovskite crystals, all of which function as photoelectric conversion layers. A bilayer crystal of 3D and 2D perovskite refers to a crystal in which 3D and 2D perovskite crystals are stacked as independent, separate layers, while a mixed 3D and 2D perovskite refers to a crystal with a structure in which both regions or domains of 2D or 2.5D layered and 3D perovskite crystals are mixed.

[0046] The crystals having a two-dimensional perovskite or 2.5-dimensional perovskite structure are preferably represented by the following general formulas [2] to [4], where n is a positive integer. R'2A n-1 B n X 3n+1 [2] R''A n-1 BnX 3n+1 [3] R'''A n BnX 3n+1 [4] In the above general formulas, [2] forms an RP (Ruddlesden-Popper) type perovskite structure, [3] forms a DJ (Dion-Jacobson) type perovskite structure, and [4] forms an ACI (Alternating cations in the interlayer) type perovskite structure.

[0047] R', R'', and R''' in the above general formulas [2] to [4] are organic molecules or metal cations which may have a substituent, and specific examples thereof include ethylammonium, propylammonium, n-butylammonium, n-hexylammonium, n-octylammonium, 1,6-hexadiammonium, iso-butylammonium, 3-(nonafluoro-tert-butyloxy)propylamine, 1,3-propanediammonium, 1,5-pentamethylenediamine, octyldiammonium, 2,2-(ethylenedioxy)bis(ethylammonium), 5-aminovaleric acid, 4-tert-butylammonium, N,N'-dimethylethylene-1,2-diammonium, 2,2,3,3,3-pentafluoropropylammonium, guanidinium, propylammonium, propargylamine, alkylammonium, cyclohexylmethylammonium, 4-(aminomethyl)piperidinium, piperidinium, pyrrolidinium, cyclohexylmethylammonium, 4-(aminomethyl)piperidinium, piperidinium, pyrrolidinium, cyclohexylmethylammonium, 4-aminomethyl)piperidin ... Cylammonium, 4-fluorophenethylammonium, 4-fluorophenethylammonium, trifluoromethylbenzylammonium, pentafluorobenzylammonium, pentafluorophenylethylammonium, 4-methoxyphenethylammonium, imidazolium, pyridinium, 3-thiophenemethylammonium, 2-thiopheneethylammonium, 2-thiopheneformamidium, 2-thiophenemethylammonium, 1-naphthylmethylammonium, 2-naphthylmethylammonium, phenethylammonium, phenylammonium, benzylammonium, 2,5-thiophenedimethylammonium, phenylpropylammonium, 1,4-phenylenedimethanamine, 3-phenyl-2-propene-1-ammonium, phenylbutylammonium, 4-tert-butyl-benzylammonium, 3-(aminomethyl)piperidinium, 4-(aminomethyl)piperidinium are preferred.

[0048] In the above general formulas [1] to [4], B is a metal atom, such as lead, tin, bismuth, zinc, titanium, antimony, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium. Among these, lead, tin, and bismuth are preferred from the viewpoint of electron orbital overlap. These metal atoms may be used alone or in combination of two or more.

[0049] X in the above general formulas [1] to [4] is a halogen atom, such as chlorine, bromine, and iodine. These halogen atoms may be used alone or in combination of two or more. Among them, halogen atoms are preferred because the perovskite crystals are easily soluble in organic solvents by containing halogen in the structure, making it possible to apply the perovskite crystals to inexpensive printing methods. Furthermore, iodine is more preferred because the energy band gap of the perovskite crystals is narrowed.

[0050] Specifically, 3D perovskites, 2D perovskites, and mixed 3D-2D perovskites are MAPbI3, FAPbCl3, FAPbI3, MAPbIαBr3-α, MAPbIαCl3-α, Cs 0.05 (MA 0.17 FA 0.83 ) 0.95 Pb(I 0.83 Br 0.17 )3, {Cs β1 (FA β2 MA 1-β2 ) 1-β1} γ1 Pb(I β3 Br 1-β3 ) γ2 , Cs 0.05 FA 0.88 MA 0.07 PbI 2.56 Br 0.44 , (FAPbI3) 0.95 (MAPbBr3) 0.05 , (FAPbI3) 0.85 (MAPbBr3) 0.15 , CsPbI3, CsPbBr3, Cs<h2 style=";text-align:left;direction:ltr"> β <h2 style=";text-align:left;direction:ltr"> (MA)<h2 style=";text-align:left;direction:ltr"> 1-β <h2 style=";text-align:left;direction:ltr"> PbI3, Cs<h2 style=";text-align:left;direction:ltr"> β <h2 style=";text-align:left;direction:ltr"> (FA)<h2 style=";text-align:left;direction:ltr"> 1-β <h2 style=";text-align:left;direction:ltr"> PbI3, MA<h2 style=";text-align:left;direction:ltr"> β <h2 style=";text-align:left;direction:ltr"> (FA)<h2 style=";text-align:left;direction:ltr"> 1-β <h2 style=";text-align:left;direction:ltr"> PbI3, MA<h2 style=";text-align:left;direction:ltr"> 0.17 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.83 <h2 style=";text-align:left;direction:ltr"> Pb(I<h2 style=";text-align:left;direction:ltr"> 0.83 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.17 <h2 style=";text-align:left;direction:ltr"> 3.Cs<h2 style=";text-align:left;direction:ltr"> 0.15 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.85 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.55 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.45 <h2 style=";text-align:left;direction:ltr"> Cs<h2 style=";text-align:left;direction:ltr"> 0.05 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.88 <h2 style=";text-align:left;direction:ltr"> MA<h2 style=";text-align:left;direction:ltr"> 0.07 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.56 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.44 <h2 style=";text-align:left;direction:ltr"> Cs<h2 style=";text-align:left;direction:ltr"> 0.15 <h2 style=";text-align:left;direction:ltr"> FA<h2 style=";text-align:left;direction:ltr"> 0.85 <h2 style=";text-align:left;direction:ltr"> PbI<h2 style=";text-align:left;direction:ltr"> 2.55 <h2 style=";text-align:left;direction:ltr"> Br<h2 style=";text-align:left;direction:ltr"> 0.45 <h2 style=";text-align:left;direction:ltr"> (PEA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (PTA)2(MA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (PEA)2(MA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (ThMA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (3BBA)2(MA)2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (ThMA)2(FA)4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (4FPEA)2(FA)<h2 style=";text-align:left;direction:ltr"> 0.3 <h2 style=";text-align:left;direction:ltr"> MA<h2 style=";text-align:left;direction:ltr"> 0.7 <h2 style=";text-align:left;direction:ltr"> 4Pb5I)<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (PDMA)FA2Pb3I<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> (3AMPY)(MA)3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (PDMA)MA5Pb6I<h2 style=";text-align:left;direction:ltr"> 19 <h2 style=";text-align:left;direction:ltr"> (PDMA)MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (TTDMA)MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (TTDMA)MA4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (BA<h2 style=";text-align:left;direction:ltr"> 0.9 <h2 style=";text-align:left;direction:ltr"> PEA<h2 style=";text-align:left;direction:ltr"> 0.1 <h2 style=";text-align:left;direction:ltr"> )2MA4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (BA<h2 style=";text-align:left;direction:ltr"> 0.9 <h2 style=";text-align:left;direction:ltr"> PEA<h2 style=";text-align:left;direction:ltr"> 0.1 <h2 style=";text-align:left;direction:ltr"> )2MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (4FPEA)2MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (4FPEA)2MA4Pb5I<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> (BA)2MA2Pb3I10, (BA)2MA3Pb4I<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> (TEA)2MA2Pb3I10 , (BA)2MA4Pb5I 16 , (BA)2MA3Pb4I 13 , CsSnBr3, CsSnI3, FA 0.75 MA 0.25 Sn 0.95 Ge 0.05 I3, FAMASnGeI3, FASnBr3, FASnI3, MA2Sn3I8, MASnBr3, MASnGeI3, and MASnI3 are preferred. Depending on the purpose, the A site, B site, and X site of the above general formula may be adjusted to be under- or over-adjusted, and the combination of β1 to β3 and γ1 to γ2 may be changed depending on the purpose. The combination of β1 to β3 and γ1 to γ2 is shown in Table 1, for example. Particularly preferred ranges are 0.03≦β1≦0.10, 0.80≦β2≦0.96, 0.80≦β3≦0.96, 0.95≦γ1≦1.05, and 2.95≦γ2≦3.05. The ranges of α and β are 0<α<3 and 0<β<1, respectively. MACl may be included as a material for forming a perovskite crystal. [Table 1] In the above specific examples, "MA" stands for methylammonium, "FA" stands for formamidinium, "PEA" stands for phenethylammonium, "PTA" stands for phenyltriethylammonium, "ThMA" stands for 2-thiophenemethylammonium, "3BBA" stands for 3-bromobenzylammonium, "3AMPY" stands for 3-(aminomethyl)pyridine, "PDMA" stands for 1,4-phenylenedimethaneammonium, "TTDMA" stands for thieno[3,2-b]thiophene-2.5-diyldimethaneammonium, "4FPEA" stands for 4-fluorophenethylammonium, "BA" stands for butylammonium, and "TEA" stands for 2-thiophenethylammonium.

[0051] The crystal with the perovskite structure preferably has a cubic structure in which a metal atom B is located at the body center, an organic molecule A at each vertex, and a halogen atom X at the face center. Although the details are not clear, it is presumed that the presence of such a structure makes it easy to change the orientation of the octahedron in the crystal lattice, thereby increasing the mobility of electrons in the crystal with the perovskite structure and improving the photoelectric conversion efficiency of the photoelectric conversion element.

[0052] The organic-inorganic perovskite compound used in the present invention is preferably a crystalline semiconductor. The crystalline semiconductor means a semiconductor in which the scattering peak can be detected by measuring the X-ray scattering intensity distribution. By using the organic-inorganic perovskite compound as a crystalline semiconductor, the mobility of electrons in the organic-inorganic perovskite compound is increased, and the photoelectric conversion efficiency of the photoelectric conversion element is improved.

[0053] The thickness of the photoelectric conversion layer according to the present invention is preferably 5 nm or more and 2000 nm or less. If the thickness is 5 nm or more, light can be sufficiently absorbed, and if the thickness is 2000 nm or less, the generated charge can be transported to each electrode. The more preferred lower limit is 50 nm or more, the more preferred upper limit is 1200 nm, the even more preferred lower limit is 100 nm, and the even more preferred upper limit is 1000 nm.

[0054] [Charge transport layer] In the present invention, the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer preferably contains a charge transport material and an insulating resin on the surface of the photoelectric conversion layer. The charge transport layer is a mixed system of a charge transport material and an insulating resin, which makes it easy to achieve both a local low-resistance charge transfer resistance element that contributes to the initial photoelectric conversion efficiency and a global high-resistance element that contributes to deterioration suppression. From this viewpoint, the insulating resin preferably has a volume resistivity of 108 Ω·cm or more.

[0055] The present inventors speculate that the preferable configuration of the charge transport layer as a means for achieving the above-mentioned configuration of the present invention and the reason for this are as follows.

[0056] On the other hand, the impedance of the low frequency side, R rec [Ω] means the recombination resistance that correlates with the difficulty of recombining electrons and holes generated in the photoelectric conversion layer, and therefore corresponds to the interface resistance between the photoelectric conversion layer and the charge transport layer. In order to set this value to a certain value or more and suppress durability deterioration, defects in the photoelectric conversion element can be sufficiently concealed by the insulating resin of the charge transport layer. However, if this value is too large, charge transfer at the interface is hindered, and the initial photoelectric conversion efficiency deteriorates. In order to balance these two, the following formula (E1) is used as described above. 1.0×10 4 <R rec ×S<1.0×10 7 (E1) had to be fulfilled.

[0057] On the other hand, the impedance of the high frequency side R ct [Ω] means the charge transfer resistance, which correlates with the ease of charge transfer when the photoelectric conversion element performs photoelectric conversion, and corresponds to the bulk resistance of the charge transport layer. In order to reduce this value to smooth the charge transfer of the photoelectric conversion element and improve the initial photoelectric conversion efficiency, the charge transport material of the charge transport layer is effective.

[0058] From the above, the charge transport layer is R rec The insulating resin contributes to increasing R ct By forming a mixture of charge transport materials that contribute to reducing the charge transport amount, the following formula (E2) of the present invention can be obtained. R rec / R ct ≧25 (E2) It becomes easier to obtain a photoelectric conversion element that satisfies the above requirements and achieves both initial photoelectric conversion efficiency and suppression of deterioration.

[0059] In the present invention, it is preferable that the charge transport material is a charge transport particle. When the charge transport material is a particle, the dispersion of the impedance on the high frequency side corresponding to the bulk resistance becomes large, The following formula (E4) P ct ≦0.95 (E4) is easily satisfied. As described above, by satisfying the above formula (E4), the variance of the impedance on the high frequency side corresponding to the charge transfer resistance becomes sufficiently large, and a sufficient number of low resistance paths for the transfer of the photocharges generated in the photoelectric conversion layer are present in the charge transport layer. As a result, it becomes easier to achieve both a high resistance recombination resistance element that contributes to global defect concealment in the surface direction of the photoelectric conversion layer and a low resistance charge transfer resistance element that contributes to a local charge transfer path of the photoelectric conversion element.

[0060] Furthermore, it is more preferable that the charge transport material is a pigment having a particle size of 10 nm to 500 nm. If the particle size is within the above range, it is easy to form a charge distribution that can suppress migration. Specific examples of the pigment include phthalocyanine pigments, azo pigments, lake pigments, quinacridone pigments, dioxazine pigments, perylene pigments, and isoindolinone pigments.

[0061] The volume ratio of the charge transport material to the insulating resin is preferably 5 times or more and 30 times or less. The following formula (E3) P rec ≧0.80 (E3) As described above, when the above formula (E3) is satisfied, the variance of the impedance on the low frequency side corresponding to the recombination resistance becomes sufficiently small, and the recombination resistance that contributes to concealing defects in the photoelectric conversion layer becomes uniform in the plane direction of the photoelectric conversion layer, so that the probability of concealing defects in the photoelectric conversion layer improves, making it easier to achieve both initial photoelectric conversion efficiency and suppression of deterioration. The ratio of the volume of the insulating resin to the volume of the charge transport material can be measured, for example, from the area ratio of the cross section obtained by FETEM / EDS as described above.

[0062] The charge transport material is more preferably a phthalocyanine compound, and more preferably has a structure represented by the following formula (Pc-2): This charge transport material tends to increase the dispersion of impedance on the high frequency side corresponding to the bulk resistance, and makes it easy to achieve both initial photoelectric conversion efficiency and degradation suppression. [ka] In the above formula (Pc-2), M represents H2 or a metal atom which may have a ligand. In the present invention, the structure of a chemical substance can be determined by nuclear magnetic resonance (NMR) spectroscopy. In particular, when M in the above formula (Pc-2) is H2, the above formula (Pc-2) is represented by the following formula (Pc-1). [ka]

[0063] Specific examples of insulating resins include polyacetal resins, acrylic resins, polyarylate resins, polycarbonate resins, polyvinyl acetate resins, polyester resins, polyamide resins, polyurethane resins, and polystyrene resins.

[0064] It is more preferable that the glass transition temperature of the insulating resin is 95° C. or lower. If the glass transition temperature is within this range, the insulating resin is likely to come into close contact with the charge transport material, and it is possible to more effectively achieve both a local low resistance element that contributes to the initial photoelectric conversion efficiency and a global high resistance element that contributes to the suppression of deterioration, and it is easy to obtain the impedance parameters of the present invention. The glass transition temperature can be determined by a differential scanning calorimeter (DSC).

[0065] It is more preferable that the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin, since such an insulating resin is likely to come into intimate contact with the charge transport material, and the impedance parameter of the present invention can be obtained more effectively.

[0066] It is more preferable that the charge transport layer contains an aromatic ring compound having a hydroxyl group different from the charge transport material and the insulating resin. By containing the aromatic ring compound having a hydroxyl group, the charge transport material and the insulating resin can be more easily contacted with each other, and the impedance parameter of the present invention can be more effectively obtained.

[0067] The photoelectric conversion element may have a second charge transport layer between the first electrode and the charge transport layer. By having the second charge transport layer, the transfer of carriers to the electrode may be facilitated.

[0068] The thickness of the charge transport layer is preferably from 1 nm to 1000 nm, more preferably from 5 nm to 500 nm, and particularly preferably from 10 nm to 200 nm.

[0069] The charge transport layer can be formed by preparing a coating solution for the charge transport layer containing the above-mentioned materials and solvent, forming this coating film on the photoelectric conversion layer, and drying it. Examples of the solvent used in the coating solution include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, and aromatic hydrocarbon-based solvents. Among these solvents, alcohol-based solvents or aromatic hydrocarbon-based solvents are preferred.

[0070] [Second Charge Transport Layer] In the present invention, from the viewpoint of film compatibility of the charge transport layer 6, a second charge transport layer may be further provided between the charge transport layer 6 and the first electrode .

[0071] The material of the second charge transport layer is not particularly limited, and examples thereof include spirofluorene compounds, triphenylamine compounds, chrysene compounds, pyrene compounds, phthalocyanine compounds, carbazole compounds, fluorene compounds, phenylcyclohexane compounds, benzidine compounds, phenoxazine compounds, phenylenediamine compounds, thiocyanate compounds, and thiophene compounds. In particular, from the viewpoint of compatibility with the film interface, it is preferable that the compound has an aromatic ring, and Spiro-OMeTAD, PTAA, and phthalocyanine compounds are preferable. The second charge transport layer may have a dopant as an additive to improve the charge transport ability. Examples of materials that can be used as a dopant include lithium compounds such as bis(trifluoromethanesulfonyl)imide lithium, cobalt compounds such as [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(3)tris(bis(trifluoromethylsulfonyl)imide)], boron compounds such as tetrakis(pentafluorophenyl)borate, molybdenum compounds such as tris[1-(methoxycarbonyl)-2-(trifluoromethyl)-ethane-1,2-dithiolene]molybdenum, organic compounds having a tetracyanoquinodimethane skeleton such as 2,3,4,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, and organic compounds having a pyridine skeleton such as 4-tert-butylpyridine.

[0072] [Control of particle size of charge transport particles] The particle size of the charge transporting particles can be changed by dispersing the coating liquid for the charge transport layer with a paint shaker, and the particle size can be reduced by extending the dispersion time, and the particle size can be further reduced by centrifuging the coating liquid for the charge transport layer. [Electron transport layer] In the photoelectric conversion element of the present invention, an electron transport layer 4 may be disposed between the second electrode 3 and the photoelectric conversion layer 5, as shown in FIG.

[0073] The material of the electron transport layer 4 is not particularly limited, and examples thereof include N-type conductive polymers, N-type low-molecular organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surfactants, etc. Specific examples thereof include cyano group-containing polyphenylene vinylene, boron-containing polymers, bathocuproine, bathophenanthrene, hydroxyquinolinatoaluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic acid compounds, fullerene compounds, perylene derivatives, phosphine oxide compounds, phosphine sulfide compounds, fluoro group-containing phthalocyanines, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, etc. In particular, tin oxide may be obtained by reacting tin chloride (2), tin chloride (4), tin chloride (2) dihydrate, or tin chloride (4) pentahydrate.

[0074] The thickness of the electron transport layer 4 is preferably 1 nm at the lower limit and 2000 nm at the upper limit. If the thickness is 1 nm or more, holes can be blocked sufficiently, and if the thickness is 2000 nm or less, the layer is unlikely to become a resistance during electron transport, and the photoelectric conversion efficiency is increased. The more preferable lower limit of the thickness is 3 nm, the more preferable upper limit is 1000 nm, the even more preferable lower limit is 5 nm, and the even more preferable upper limit is 500 nm.

[0075] [Photoelectric conversion device] A photoelectric conversion device can be constructed by using a plurality of photoelectric conversion elements of the present invention. When a plurality of photoelectric conversion elements are connected, such a photoelectric conversion device can also be called a photoelectric conversion cell or a photoelectric conversion module. The photoelectric conversion element may be a stack of elements with different absorption wavelengths in order to increase the output voltage. The photoelectric conversion device may have the photoelectric conversion element of the present invention and an inverter. The inverter may be a converter that converts direct current to alternating current. The photoelectric conversion device may have a storage unit connected to the photoelectric conversion element. The storage unit is not limited as long as it can store electricity. For example, a secondary battery using lithium ions or the like, an all-solid-state battery, an electric double layer capacitor, etc. may be mentioned. In order to impart a function such as maintaining or increasing the amount of incident light, a surface layer that is resistant to water and dirt, or a function of collecting or guiding light may be added.

[0076] [Mobile object] FIG. 6 is a perspective view showing a schematic diagram of an embodiment of a moving body equipped with a photoelectric conversion element of the present invention. The moving body 30 has a photoelectric conversion element 31 of the present invention and a vehicle 32 equipped with the photoelectric conversion element 31. The photoelectric conversion element 31 is disposed at a position on the vehicle 32 where it can receive external light. If the moving body 30 is an automobile, it may be disposed on the roof. The electric energy obtained by the photoelectric conversion element 31 may be used as the power source for the moving body 30 or for other electric devices. The electric energy generated from the power source for the moving body 30 may be used to power the photoelectric conversion element 31. If the moving body 30 is an automobile, the frictional energy generated by the brakes may be converted into electric energy and used to control the photoelectric conversion element 31.

[0077] The moving body 30 may be, for example, an automobile, a motorcycle, a railroad vehicle, a ship, an artificial satellite, an airplane, or a flying object including a drone. The configuration of the body 32 of the moving body 30 is not particularly limited, but it is preferable that the body 32 be made of a high-strength material.

[0078] [Building materials] 7 is a perspective view showing an embodiment of a building material including a photoelectric conversion element of the present invention. The building material 40 may be the roof of a building. The building material 40 of this embodiment has a photoelectric conversion element 41 of the present invention, a protective member 42 that protects the photoelectric conversion element 41, a heat dissipation member 43, and exteriors 44a and 44b.

[0079] The building material 40 of the present invention may have a heat dissipation member 43 having a higher thermal conductivity than the photoelectric conversion element 41. When used on a roof or the like, the temperature of the photoelectric conversion element 41 may increase due to sunlight, and the photoelectric conversion efficiency may decrease. The use of the heat dissipation member 43 can reduce the decrease in photoelectric conversion efficiency. Examples of the heat dissipation member 43 include metal, alloy, liquid metal, and liquid resin.

[0080] Furthermore, the building material 40 of the present invention may have exteriors 44a and 44b. The exteriors 44a and 44b may emit different colors or may be the same. 44a and 44b may be made of the same material or different materials. Paint or a transparent substrate may be used as the exterior. A material with low light absorption and high heat insulation is preferable.

[0081] In addition to the above application examples, the following application examples can be mentioned. Portable devices include, for example, calculators, sensors, and small solar panels. Wearable devices include, for example, eyeglass-type terminals, wristwatch-type terminals, and portable medical equipment. Sheet structures supported by multiple frames include, for example, tents, vinyl greenhouses, and truck beds. Fixed structures include, for example, road panels, floating panels, building materials that take advantage of the flexibility of the substrate, wall-type building materials, glass-type building materials, and mega solar panels.

[0082] [About the manufacturing method of photoelectric conversion element] A method for producing a photoelectric conversion element of the present invention includes the steps of forming a first electrode, forming a second electrode, and forming a photoelectric conversion layer containing crystals with a perovskite structure between the first electrode and the second electrode. Each step of the manufacturing method will be described below.

[0083] [Step of forming a first electrode and step of forming a second electrode] The method for manufacturing a photoelectric conversion element of the present invention includes a step of forming a first electrode and a step of forming a second electrode. In the step of forming the first electrode and the step of forming the second electrode, an appropriate method can be selected according to the material of the first electrode and the material of the second electrode, respectively. Examples of such methods include, but are not limited to, sputtering vacuum deposition, CVD (vapor phase deposition), and SPD (spray pyrolysis deposition). The materials of the first electrode and the second electrode are as described above. When either or both of the first electrode and the second electrode are transparent electrodes, the thickness of the transparent electrode is preferably 0.03 μm or more and 3 μm or less. When manufacturing a solar cell, cutting may be performed between each process to form a circuit. Examples of cutting include mechanical patterning and laser patterning.

[0084] [Modularization process] The element having the electrodes formed thereon may be sealed. Examples of the sealing method include sealing with a resin or sealing with a film. Examples of the material used for sealing include silazane, silicone rubber, a resin having a siloxane skeleton, and glass. In addition, from the viewpoint of preventing adhesion between elements that occurs when the elements are wound in a roll-to-roll system, the surfaces of the encapsulated elements may be subjected to a hairline treatment.

[0085] [Step of forming photoelectric conversion layer] The step of forming the photoelectric conversion layer may include a step of applying a liquid containing the material of the photoelectric conversion layer described above. Examples of the application method include spin coating, blade coating, slit die coating, screen printing, bar coater, casting, printing transfer, immersion and pulling, inkjet, spraying, and vacuum deposition. Among these, a method is appropriately selected according to the characteristics of the photoelectric conversion layer to be produced, such as thickness control and orientation control. In order to remove the solvent or dispersion medium from the liquid containing the applied photoelectric conversion layer material, annealing may be performed under reduced pressure or in an inert atmosphere (nitrogen or argon atmosphere). The temperature of the annealing is preferably 40° C. or higher and 300° C. or lower, and more preferably 50° C. or higher and 150° C. or lower. Note that annealing is preferable because it may increase the contact area at the interface between the stacked layers by allowing the materials constituting each layer to penetrate into each other, thereby increasing the short-circuit current.

[0086] [Step of forming charge transport layer] The method for producing the photoelectric conversion element of the present invention may include a step of forming a charge transport layer between the photoelectric conversion layer and the first electrode. The step of forming the charge transport layer is preferably a method of applying a resin solution in which an insulating resin is dissolved, so that when there are gaps between perovskite crystal grains, the insulating resin can easily and preferentially penetrate therein. Examples of the step of forming the charge transport layer include the following: A method of disposing charge transport particles on the surface of the photoelectric conversion layer and then applying a resin solution in which an insulating resin is dissolved. Alternatively, a method of applying a resin solution in which an insulating resin is dissolved on the surface of the photoelectric conversion layer and then disposing charge transport particles. Alternatively, a method of applying a solution in which charge transport particles are dispersed in a resin solution in which an insulating resin is dissolved on the surface of the photoelectric conversion layer.

[0087] [Impedance measurement and analysis] The impedance is measured by connecting the first and second electrodes of the photoelectric conversion element to an impedance analyzer through an appropriate probe, and applying a DC voltage component V DC =0[V], root mean square of AC voltage component V rms = 50 [mV] AC voltage with frequency 1.0 × 10 -2 [Hz]~1.0×10 6 This is done by applying a voltage that is varied between [Hz].

[0088] For the measurement, various impedance analyzers can be used, such as ModuLab XM MTS (manufactured by Solartron Corp.). Alternatively, SI1287 electrochemical interface (manufactured by Toyo Technica Corp.) can be used as the power supply, DIELECTRIC INTERFA CE solartron 1296 (manufactured by Toyo Technica Corp.) as the current amplifier, IMPEDA NCE / GAINPHASE ANALYZER solartron SI1260 (manufactured by Toyo Technica Corp.) as the ammeter, and Solartron Material Research and Test software Ver.3.0.1 (manufactured by Solartron Analytical Corp.) can be used as the measurement software.

[0089] The obtained data can be analyzed using various analytical software, for example, the analytical software Zview Ver. 4 (manufactured by Scribner Associates).

[0090] In the present invention, a plot based on the impedance measurement results with the horizontal axis being frequency [Hz] and the vertical axis being phase [deg] (phase graph of a Bode diagram), a Nyquist plot with the horizontal axis being the impedance real part Z' [Ω] and the vertical axis being the impedance imaginary part Z'' [Ω], and the like are analyzed. Specifically, in particular, for the analysis of a Nyquist plot, a two-axis graph consisting of the real component Z' and imaginary component Z'' of impedance Z is created, and when it is expressed in coordinates (Z', Z''), this is fitted using an appropriate equivalent circuit. In this case, in the low frequency range (1.0×10 -2 [Hz] or more 1.0×10 2 [Hz]) and high frequency range (1.0×10 2 [Hz] or more 1.0×10 6[Hz] (below), to obtain the indices of the respective resistors (R) and constant phase elements (CPE), it is easy to analyze using an equivalent circuit in which at least two "resistor element - constant phase element parallel circuits (RCPE parallel circuits)" are connected in series. For example, an equivalent circuit in which one series resistor (R1), one series inductor (L1), and three "resistor element - constant phase element parallel circuits" ("R4 - CPE3", "R2 - CPE1", "R3 - CPE2") are connected in series, as shown in FIG. 4, can be cited. FIG. 2 shows, in a Nyquist plot, the result of fitting the photoelectric conversion element 4 according to the present invention to the equivalent circuit of FIG. 4, which was carried out in Example 4 of the present invention. However, the impedance analysis of the present invention is not limited to the use of such an equivalent circuit. Also, another analysis method without using an equivalent circuit, for example, extracting only the necessary arcs on the Nyquist plot and fitting with one resistor element - constant phase element parallel circuit to obtain the impedance parameters of the present invention may be used.

[0091] In the present invention, ModuLab XM MTS (manufactured by Solartron) was used for impedance measurement. The measurement conditions are as follows. <Measurement Conditions of ModuLab XM MTS> Experiment type:Sample&Reference Instrument configuration:Mat+Femto Ammeter Ground:Internal DC:0V AC:0.05V rms Frequency: 1 MHz to 0.01 Hz Number of measurement points: 6 point / decade

Example

[0092] Hereinafter, the present invention will be described in more detail using examples and comparative examples. The present invention is not limited in any way by the following examples as long as it does not exceed the gist thereof. In the description of the following examples, "parts" means mass basis unless otherwise specified.

[0093] Preparation of particle 1 Process (1) In a nitrogen flow atmosphere, 5.46 parts of orthophthalonitrile and 45 parts of α-chloronaphthalene were put into a reaction vessel, and then heated to a temperature of 30°C and maintained at this temperature. Next, 3.75 parts of gallium trichloride were put in at this temperature (30°C). The water concentration of the mixed liquid at the time of putting in was 150 ppm. Then, the temperature was raised to 200°C. Next, under a nitrogen flow atmosphere, the reaction was carried out at a temperature of 200°C for 4.5 hours, and then cooled. When the temperature reached 150°C, the product was filtered. The obtained filtrate was dispersed and washed using N,N-dimethylformamide at a temperature of 140°C for 2 hours, and then filtered. The obtained filtrate was washed with methanol and then dried to obtain chlorogallium phthalocyanine particles with a yield of 71%.

[0094] Process (2) 4.65 parts of the chlorogallium phthalocyanine particles were dissolved in 139.5 parts of concentrated sulfuric acid at a temperature of 10° C., dropped into 620 parts of ice water under stirring to reprecipitate, and filtered under reduced pressure using a filter press. At this time, No. 5C (manufactured by Advantec Co., Ltd.) was used as the filter. The obtained wet cake (filtrate) was dispersed and washed with 2% ammonia water for 30 minutes, and then filtered using a filter press. Next, the obtained wet cake (filtrate) was dispersed and washed with ion-exchanged water, and then filtration using a filter press was repeated three times. Finally, freeze-drying was performed to obtain hydroxygallium phthalocyanine particles (hydrated hydroxygallium phthalocyanine particles) with a solid content of 23% by mass at a yield of 71%. The hydroxygallium phthalocyanine particles were dried in a Hyper Dry dryer (product name: HD-06R, frequency (oscillation frequency): 2455 MHz ± 15 MHz, manufactured by Japan Biocon) to obtain hydroxygallium phthalocyanine (HOGaPc) particles (crystals) with a moisture content of 1.0 mass% or less.

[0095] Process (3) Five parts of the hydroxygallium phthalocyanine particles were mixed with 5 parts of N-methylformamide solvent, and the mixture was dispersed for 6 hours using a sand mill (TSG-1 / 4G-4U, manufactured by Igarashi Machinery Manufacturing (now Imex), disk diameter 70 mm, number of disks 5) containing 5 parts of glass beads, filtered, and dried to obtain Particle 1 (specific gravity 1.6).

[0096] Preparation of resin solution 1 1.0 g of polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd., specific gravity 1.6) was dissolved in 19 g of 2-propanol with stirring for 24 hours to obtain resin solution 1.

[0097] (Fabrication of photoelectric conversion element) (Fabrication of photoelectric conversion element 1) [Formation of Electron Transport Layer] A glass substrate with ITO was cleaned, and a 5-fold diluted tin oxide (2) colloidal solution (15% water dispersion, manufactured by Alfa Aesar) was spin-coated onto it, and then heated at 150°C for 30 minutes to form a thin-film electron transport layer with a thickness of 16 nm.

[0098] [Formation of photoelectric conversion layer] 0.487 g of lead bromide, 1.034 g of formamidium iodide, 2.903 g of lead iodide, and 0.139 g of methylammonium bromide were dissolved in 4.25 g of N,N-dimethylformamide and 1.216 g of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 1). Furthermore, 0.100 g of cesium iodide was dissolved in 0.285 g of dimethyl sulfoxide, and the mixture was stirred for 1 hour (solution 2). The dissolved cesium iodide solution (solution 2) was then added to solution 1 to prepare a coating solution for the photoelectric conversion layer. This coating solution was spin-coated on the electron transport layer to produce Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 A photoelectric conversion layer having a thickness of 600 nm was formed from the photoelectric conversion layer 3.

[0099] [Formation of Charge Transport Layer] 0.1g of the particles 1 and 0.01g of a calixarene compound (JP Patent Publication 2003-207913) were mixed with 10.6g of 2-propanol, and 11g of beads (zirconia beads, Treceram (registered trademark) zirconia beads, 0.3mm) were encapsulated in this mixture, and dispersion was performed for 3 hours using a paint shaker (manufactured by Toyo Seiki Co., Ltd.). Then, 0.2g of resin solution 1 was added, and dispersion was performed again for 4 hours using a paint shaker to prepare a coating liquid for a charge transport layer. This coating liquid for a charge transport layer was spin-coated on the photoelectric conversion layer to form a charge transport layer having a thickness of 180nm.

[0100] [Introduction of a second charge transport layer] 0.15 g of Spiro-OMeTAD as a material for the second charge transport layer was dissolved in 2.2 g of chlorobenzene. 36 μL of an acetonitrile solution obtained by dissolving 0.2 g of lithium bis(trifluoromethanesulfonyl)imide in 0.3 g of acetonitrile and 60 μL of 4-tert-butylpyridine (TBP) were added to this chlorobenzene solution and mixed. Furthermore, 58 μL of an acetonitrile solution obtained by dissolving 0.11 g of [tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)cobalt(3) tris(bis(trifluoromethylsulfonyl)imide)] in 0.3 g of acetonitrile was mixed to prepare a coating solution for the second charge transport layer. This was applied by spin coating on the charge transport layer to form a second charge transport layer with a thickness of 100 nm.

[0101] [Formation of the first electrode] On the second charge transport layer, a layer having a thickness of 80 nm and an area of ​​0.09 cm 2 The gold electrodes were formed by vacuum deposition to obtain a photoelectric conversion element 1. In the example according to the present invention, the first electrode was a small electrode.

[0102] [Analysis of compound amounts] The electrode surface of the photoelectric conversion element was peeled off to expose the charge transport layer surface. This charge transport layer surface was wiped with a cotton swab or the like soaked in a solvent, dissolved in heavy water sulfuric acid, and 1H-NMR measurement (apparatus: AVANCE3-500, manufactured by BRUKER) was performed. In addition, the peeled off charge transport layer components were subjected to mass and structure analysis by elemental analysis such as GPC, MALDI-TOF-MS, IR, gas chromatography, XPS, and EDX to confirm the presence of compounds. The film thickness was confirmed by cutting the photoelectric conversion element, fixing it to an inclined sample stage, and then observing the cross-section with a SEM (apparatus: Carl Zeiss, SmartSEM).

[0103] [Analysis of particle size of charge transport material] The particle size of the charge transport material is the number average particle size in the particle size distribution. In the present invention, the particle size of the charge transport material is derived by an image imaging method using a TEM. Specifically, first, the obtained TEM image of the cross section of the charge transport layer is used to extract N particles (N is 1000 or more) using image processing software Photoshop (Adobe). Next, the area S of each particle is calculated, and the diameter of a circle with the same area (=2×(S / π)1 / 2) is taken as the particle size, and the average value of the median 80% of the N particles is taken. The element configuration of the photoelectric conversion element 1 is shown in Table 2.

[0104] (Preparation of photoelectric conversion elements 2 to 7 and 21) Photoelectric conversion elements 2 to 7 and 21 are obtained in the same manner as in photoelectric conversion element 1, except that the volume ratio of the charge transport material to the insulating resin is changed to the value shown in Table 2.

[0105] (Fabrication of photoelectric conversion element 8) In forming the charge transport layer, the coating liquid for the charge transport layer obtained by paint shaker dispersion is further centrifuged (at 15,000 rpm for 6 minutes) to reduce the particle size in the dispersion liquid, and then the volume ratio of the charge transport material to the insulating resin is adjusted to be 10 times, and photoelectric conversion element 8 is obtained in the same manner as photoelectric conversion element 1.

[0106] (Fabrication of photoelectric conversion element 9) Photoelectric conversion element 9 is obtained in the same manner as photoelectric conversion element 1, except that the polyvinyl butyral (product name: BM-2, manufactured by Sekisui Chemical Co., Ltd.) is replaced with polyvinyl butyral (product name: BX-1, manufactured by Sekisui Chemical Co., Ltd.).

[0107] (Fabrication of photoelectric conversion element 10) Photoelectric conversion element 10 is obtained in the same manner as photoelectric conversion element 1, except that the calixarene compound is changed to 2-naphthol.

[0108] (Fabrication of photoelectric conversion element 11) Photoelectric conversion element 11 is obtained in the same manner as photoelectric conversion element 1, except that the particles 1 are nickel phthalocyanine particles.

[0109] (Fabrication of photoelectric conversion element 12) Photoelectric conversion element 12 is obtained in the same manner as photoelectric conversion element 1, except that the second charge transport layer is not provided.

[0110] (Fabrication of photoelectric conversion element 13) Photoelectric conversion element 13 is obtained in the same manner as photoelectric conversion element 1, except that the calixarene compound is not used.

[0111] (Fabrication of photoelectric conversion element 14) Photoelectric conversion element 14 is obtained in the same manner as photoelectric conversion element 1, except that polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich, glass transition temperature 70° C.) is used instead of the polyvinyl butyral.

[0112] (Fabrication of photoelectric conversion element 15) Photoelectric conversion element 15 is obtained in the same manner as photoelectric conversion element 1, except that the polyvinyl butyral is replaced with polymethyl methacrylate (PMMA, manufactured by Sigma-Aldrich Corporation, glass transition temperature 100° C.).

[0113] (Fabrication of photoelectric conversion element 16) A photoelectric conversion element 16 is obtained in the same manner as in the photoelectric conversion element 1, except that the particles 1 are particles having a compound represented by (Pc-3). [ka]

[0114] (Fabrication of photoelectric conversion element 17) Photoelectric conversion element 17 is obtained in the same manner as photoelectric conversion element 1, except that the particles 1 are quinacridone particles.

[0115] (Fabrication of photoelectric conversion element 18) A photoelectric conversion element 18 was obtained in the same manner as in Example 1, except that the composition of the photoelectric conversion layer was changed to MAPbI3.

[0116] (Fabrication of photoelectric conversion element 19) Photoelectric conversion element 19 is obtained in the same manner as photoelectric conversion element 1, except that a layer similar to the second charge transport layer formed in photoelectric conversion element 1 is formed as the charge transport layer of photoelectric conversion element 19, and a second charge transport layer is not provided on the charge transport layer.

[0117] (Fabrication of photoelectric conversion element 20) Photoelectric conversion element 20 is obtained in the same manner as photoelectric conversion element 1, except that the particles 1 are not used.

[0118] (Fabrication of photoelectric conversion element 22) Photoelectric conversion element 22 is obtained in the same manner as photoelectric conversion element 15, except that the particle 1 is Spiro-OMeTAD, the volume ratio of the charge transport material to the insulating resin is 1, the thickness of the charge transport layer is 100 nm, no calixarene compound is used, and no second charge transport layer is provided on the charge transport layer.

[0119] (Fabrication of photoelectric conversion element 23) A photoelectric conversion element 23 is obtained in the same manner as the photoelectric conversion element 22, except that the thickness of the charge transport layer is set to 180 nm.

[0120] (Fabrication of photoelectric conversion element 24) A photoelectric conversion element 24 is obtained in the same manner as the photoelectric conversion element 22, except that the thickness of the charge transport layer is set to 300 nm.

[0121] (Fabrication of photoelectric conversion element 25) Photoelectric conversion element 25 is obtained in the same manner as photoelectric conversion element 15, except that the particles 1 are Spiro-OMeTAD, the thickness of the charge transport layer is 180 nm, and a second charge transport layer is not provided on the charge transport layer.

[0122] (Fabrication of photoelectric conversion element 26) A photoelectric conversion element 26 is obtained in the same manner as in photoelectric conversion element 1, except that the particles 1 are changed to nickel (II) phthalocyanine-tetrasulfonic acid tetrasodium salt particles and the insulating resin is changed to PEDOT:PSS.

[0123] (Fabrication of photoelectric conversion element 27) Photoelectric conversion element 27 is obtained in the same manner as photoelectric conversion element 1, except that the particles 1 are particles having a compound represented by the following formula (Pc-4) and further the insulating resin is P3HT. [ka]

[0124] Example 1 [evaluation] The impedance of the photoelectric conversion element 1 produced in (Production of photoelectric conversion element) was measured. A ModuLab XM MTS (manufactured by Solartron) was used for the measurement. The obtained impedance data was fitted using the equivalent circuit shown in FIG. 4 as shown in FIG. 2 (FIG. 2 is an example of photoelectric conversion element 4), and R rec ×S [Ω cm 2 ], R rec / R ct , P rec , P ct The results are shown in Table 3.

[0125] Next, a power supply (KEITHLEY, Model 236) was connected between the electrodes of the photoelectric conversion element 1, and the intensity was set to 110 mW / cm 2The initial photoelectric conversion efficiency was measured by irradiating a constant amount of light using a solar simulator (manufactured by Yamashita Denso Co., Ltd.) and measuring the generated current and voltage. Measurements were also performed at 10 electrodes for each element, and the average value was used as the representative value for that element. The results are shown in Table 3. After that, 10,000 Lx of light was continuously irradiated from a white LED, and the photoelectric conversion efficiency after 50 days was measured. The maintenance rate of the photoelectric conversion efficiency after 50 days relative to the initial photoelectric conversion efficiency obtained was then evaluated. The results are shown in Table 3. In Table 3, the photoelectric conversion efficiency in Example 1 is taken as 100%, and the ratio relative to this is shown as the conversion efficiency of each element.

[0126] For Examples 2 to 18 and Comparative Examples 1 to 9, the initial photoelectric conversion efficiency and the maintenance rate of the photoelectric conversion efficiency were evaluated in the same manner as in Example 1. The results are shown in Table 3. In Comparative Example 2, the initial photoelectric conversion was not measured, and the maintenance rate of photoelectric conversion could not be evaluated.

[0127] [Table 2]

[0128] [Table 3]

[0129] The disclosure of this embodiment includes the following configuration. [Configuration 1] A photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, The smaller of the electrode areas of the first electrode and the second electrode is defined as S [cm 2 ]year, A DC voltage component V DC =0[V], root mean square of AC voltage component V rms = 50 [mV] AC voltage with frequency 1.0 × 10 -2 [Hz]~1.0×10 6When the impedance is measured while changing the frequency between [Hz], Based on the impedance measurement results, the horizontal axis is frequency [Hz] and the vertical axis is phase [deg]. 1.0×10 -2 [Hz] or more 1.0×10 2 The phase of the impedance has a maximum value in a low frequency range of less than [Hz], 1.0×10 2 [Hz] or more 1.0×10 6 The phase of the impedance has a maximum value in the high frequency range of Hz or less, In a Nyquist plot based on the impedance measurement results, the horizontal axis is the real part of the impedance Z' [Ω] and the vertical axis is the imaginary part of the impedance Z'' [Ω]. The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the low frequency range with a parallel circuit of a resistor element and a constant phase element is rec [Ω] satisfies the following formula (E1), 1.0×10 4 <R rec ×S<1.0×10 7 (E1) The maximum resistance value R obtained by fitting the arc corresponding to the maximum phase value in the high frequency range with a parallel circuit of a resistor element and a constant phase element is ct [Ω] and the R rec [Ω] satisfies the following formula (E2); R rec / R ct ≧25 (E2) A photoelectric conversion element comprising: [Configuration 2] R rec The exponent P of the constant phase element obtained by fitting to obtain [Ω] rec The photoelectric conversion element according to configuration 1, which satisfies the following formula (E3): P rec ≧0.80 (E3) [Configuration 3] R ct The exponent P of the constant phase element obtained by fitting to obtain [Ω] ctThe photoelectric conversion element according to configuration 1 or 2, which satisfies the following formula (E4): P ct ≦0.95 (E4) [Configuration 4] R rec The photoelectric conversion element according to any one of configurations 1 to 3, wherein [Ω] satisfies the following formula (E5): 1.0×10 5 <R rec ×S<1.0×10 6 (E5) [Configuration 5] R ct [Ω] and the above R rec 5. The photoelectric conversion element according to any one of configurations 1 to 4, wherein [Ω] satisfies the following formula (E6): R rec / R ct ≧50 (E6) [Configuration 6] The photoelectric conversion element according to any one of configurations 1 to 5, wherein the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, and the charge transport layer contains a charge transport material and an insulating resin on a surface of the photoelectric conversion layer. [Configuration 7] 7. The photoelectric conversion element according to configuration 6, wherein the charge transport material is a charge transport particle. [Configuration 8] 8. The photoelectric conversion element according to configuration 7, wherein the charge transporting particles have an average particle size of 10 nm to 500 nm. [Configuration 9] 7. The photoelectric conversion element according to configuration 6, wherein a volume ratio of the charge transport material to the insulating resin is 5 to 30 times. [Configuration 10] 7. The photoelectric conversion element according to configuration 6, wherein the charge transport material is a phthalocyanine compound. [Configuration 11] 11. The photoelectric conversion element according to configuration 10, wherein the phthalocyanine compound has a structure represented by the following formula (Pc-2): [ka] (In the above formula (Pc-2), M represents H2 or a metal atom which may have a ligand.) [Configuration 12] 7. The photoelectric conversion element according to configuration 6, wherein the insulating resin has a glass transition temperature of 95° C. or lower. [Configuration 13] 7. The photoelectric conversion element according to configuration 6, wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin. [Configuration 14] 7. The photoelectric conversion element according to configuration 6, wherein the charge transport layer contains an aromatic ring compound having a hydroxyl group different from the charge transport material and the insulating resin. [Configuration 15] The photoelectric conversion element according to configuration 6, further comprising a second charge transport layer between the first electrode and the charge transport layer. [Configuration 16] 16. A photoelectric conversion device comprising the photoelectric conversion element according to any one of configurations 1 to 15. [Explanation of symbols]

[0130] 1 Photoelectric conversion element 2. Board 3 Second electrode 4 Electron transport layer 5 Photoelectric conversion layer 6 Charge transport layer 7 First electrode 30 Mobile 31, 41 Photoelectric conversion element 32 Aircraft 40 Building materials 42 Protective materials 43 Heat dissipation materials 44a, 44b Exterior

Claims

1. A photoelectric conversion element having a first electrode, a second electrode, and a photoelectric conversion layer including a crystal having a perovskite structure and disposed between the first electrode and the second electrode, The smaller of the electrode area of ​​the first electrode and the electrode area of ​​the second electrode is defined as S [cm ２ ]year, A DC voltage component V ＤＣ = 0 [V], the root mean square of the AC voltage component V ｒｍｓ = 50 [mV] AC voltage with frequency 1.0 x 10 －２ [Hz] ~1.0×10 ６ When the impedance is measured while changing the frequency between [Hz], In a plot based on the impedance measurement results, the horizontal axis is frequency [Hz] and the vertical axis is phase [deg]. 1.0 x 10 －２ [Hz] or more 1.0×10 ２ The phase of the impedance has a maximum value in a low frequency range of less than [Hz], 1.0 x 10 ２ [Hz] or more 1.0×10 ６ The phase of the impedance has a maximum value in a high frequency range of 100 Hz or less, In a Nyquist plot based on the impedance measurement results, the horizontal axis is the real impedance part Z' [Ω] and the vertical axis is the imaginary impedance part Z'' [Ω], The maximum resistance value R among the resistance values ​​obtained by fitting the arc corresponding to the maximum phase value in the low frequency range with a parallel circuit of a resistor element and a constant phase element is ｒｅｃ [Ω] satisfies the following formula (E1), 1.0×10 ４ ≦R ｒｅｃ ×S≦1.0×10 ７ (E1) The maximum resistance value R among the resistance values ​​obtained by fitting the arc corresponding to the maximum phase value in the high frequency range with a parallel circuit of a resistor element and a constant phase element is ｃｔ [Ω] and the R ｒｅｃ [Ω] satisfies the following formula (E2), R ｒｅｃ / R ｃｔ ≧25 (E2) A photoelectric conversion element comprising:

2. The R ｒｅｃ The exponent P of the constant phase element obtained by fitting to obtain [Ω] ｒｅｃ The photoelectric conversion element according to claim 1 , which satisfies the following formula (E3): P ｒｅｃ ≧0.80 (E3)

3. The R ｃｔ The exponent P of the constant phase element obtained by fitting to obtain [Ω] ｃｔ The photoelectric conversion element according to claim 1 , which satisfies the following formula (E4): P ｃｔ ≦0.95 (E4)

4. The R ｒｅｃ The photoelectric conversion element according to claim 1 , wherein [Ω] satisfies the following formula (E5): 1.0×10 ５ <R ｒｅｃ ×<<1.0×10 ６ (E5)

5. The R ｃｔ [Ω] and the R ｒｅｃ The photoelectric conversion element according to claim 1 , wherein [Ω] satisfies the following formula (E6): R ｒｅｃ / R ｃｔ ≧50 (E6)

6. The photoelectric conversion element according to claim 1 , wherein the photoelectric conversion element has a charge transport layer between the photoelectric conversion layer and the first electrode, the charge transport layer containing a charge transport material and an insulating resin on a surface of the photoelectric conversion layer.

7. The photoelectric conversion element according to claim 6 , wherein the charge transport material is a charge transport particle.

8. 8. The photoelectric conversion element according to claim 7, wherein the charge transporting particles have an average particle size of 10 nm or more and 500 nm or less.

9. 7. The photoelectric conversion element according to claim 6, wherein a volume ratio of the charge transport material to the insulating resin is 5 times or more and 30 times or less.

10. The photoelectric conversion element according to claim 6 , wherein the charge transport material is a phthalocyanine compound.

11. The photoelectric conversion element according to claim 10, wherein the phthalocyanine compound has a structure represented by the following formula (Pc-2): 【Chemistry 1】 (In the above formula (Pc-2), M represents H2 or a metal atom which may have a ligand.)

12. The photoelectric conversion element according to claim 6 , wherein the insulating resin has a glass transition temperature of 95° C. or lower.

13. The photoelectric conversion element according to claim 6 , wherein the insulating resin is a polyvinyl acetal resin or a polyvinyl butyral resin.

14. The photoelectric conversion element according to claim 6 , wherein the charge transport layer contains an aromatic ring compound having a hydroxyl group different from the charge transport material and the insulating resin.

15. The photoelectric conversion element according to claim 6 , further comprising a second charge transport layer between the first electrode and the charge transport layer.

16. A photoelectric conversion device comprising the photoelectric conversion element according to any one of claims 1 to 15.

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