JP2018030730A - Film, optical device, electronic device, photoelectric conversion apparatus, and film production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrically and optically available film with low toxicity.SOLUTION: The film contains a crystal CL having a composition represented by general formula ABX. A is one or more selected from the group consisting of Ag, Cu, In, Na, K and NH. B is one or more selected from the group consisting of Bi, Sb and La. X is one or more selected from the group consisting of F, Cl, Br, I, CN and SCN. Here, (n+3 m)×0.8≤z≤(n+3m)×1.2 is satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a film, an optical device, an electronic device, a photoelectric conversion apparatus, and a film manufacturing method.

  In recent years, development of new materials used for photoelectric conversion devices and the like has been advanced. Such materials are required to be stable and have low toxicity.

Non-Patent Document 1 describes the crystal structures of AgBiI ₄ and Ag ₃ BiI ₆ . Non-cited document 2 shows a phase diagram including AgBiI ₄ and describes that AgBiI ₄ is black and AgBiBr ₄ is yellow.

Thorsten Oldag and four others, “Solvothermale Synthese und Bestimmung der Kristallstrukturen von AgBiI4 und Ag3BiI6”, Zeitschrift fur (u is U Umlaut) anorganische Chemund allme, Germany February 21, 2005, volume 631, p. 677-682 К. Дзеранова, "Physicochemical analysis of binary and ternary systems of bismuth (III) halides and metals (I, II) halides (" Физико-химический анализ двойных и тройных систади металлов (I, II) ",)", Doctoral Dissertation, (Russia), 2004, p. 67-69

On the other hand, in order to use a new material for a device or the like, it is necessary to use the material as a film. Further, in Non-Patent Document 1 and Non-cited Document 2, the characteristics and functions of AgBiI ₄ and Ag ₃ BiI ₆ have not been sufficiently investigated.

  The present invention provides a film that has low toxicity and can be used electrically and optically.

According to the present invention,
Includes a crystal having a composition represented by the general formula _A n _B m _{X z,}
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds,
The crystal is
Including a first ion of an element or group of elements contained in X,
There is provided a film having a structure in which a plurality of octahedral units each consisting of six first ions are connected by sharing two first ions on a ridge.

According to the present invention,
An optical device comprising the above film is provided.

According to the present invention,
An electronic device comprising the above film is provided.

According to the present invention,
A first electrode;
A second electrode;
A photoelectric conversion layer located between the first electrode and the second electrode,
The photoelectric conversion layer is provided with a photoelectric conversion device including the above film.

According to the present invention,
A method for producing a film containing crystals,
Forming a precursor film each containing one or more elements or element groups A, B, and X, and a solvent;
Drying the precursor film at a first temperature;
Heat-treating the precursor film at a second temperature higher than the first temperature,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
It said crystal has a composition represented by the general formula _A n _B m _{X z,}
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds,
The crystal is
Including a first ion of an element or group of elements contained in X,
There is provided a film manufacturing method in which a plurality of octahedral units each including six first ions have a structure in which two first ions on a ridge are shared and connected to each other.

According to the present invention,
Includes a crystal having a composition represented by the general formula _A n _B m _{X z,}
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
A film in which (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 and n / m ≧ 0.8 is provided.

According to the present invention,
A first electrode;
A second electrode;
A photoelectric conversion layer located between the first electrode and the second electrode,
The photoelectric conversion layer is provided with a photoelectric conversion device having the above film.

According to the present invention,
A method for producing a film containing crystals,
Forming a precursor film each containing one or more elements or element groups A, B, and X, and a solvent;
Drying the precursor film at a first temperature;
Heat-treating the precursor film at a second temperature higher than the first temperature,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
It said crystal has a composition represented by the general formula _A n _B m _{X z,}
A method for producing a film in which (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 and n / m ≧ 0.8 is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the film | membrane which has low toxicity and can be utilized electrically and optically can be provided.

It is a figure which illustrates the structure of crystal | crystallization CL contained in the film | membrane concerning 1st Embodiment. It is a figure which shows the structure of an octahedron unit. It is a figure which shows the laminated structure of a plate-shaped unit. (A) is a diagram showing an ultraviolet-visible (UV-Vis) Tauc plot of the UV-Vis spectra obtained by measuring the _Ag 3 BiI ₆ film in spectroscopy, (b), the ultraviolet-visible (UV-Vis FIG. 4 is a diagram showing a Tauc plot of a UV-Vis spectrum obtained by measuring an In ₃ BiI ₆ film by spectroscopy. It is a diagram showing the photoluminescence spectrum of the Ag ₃ BiI ₆ film. Ag ₃ is a diagram illustrating the attenuation profile of the photoluminescence BiI ₆ film. It is sectional drawing which illustrates the structure of the photoelectric conversion apparatus which concerns on 2nd Embodiment. The cross-section of a photoelectric conversion device comprising a Ag ₃ BiI ₆ film is a diagram showing a result of observation with an electron microscope. _{m-TiO 2, Ag 3 BiI} 6, and is a diagram showing the relationship between the energy level of PTAA. (A) ~ (d) _are views showing a distribution of characteristics of the photoelectric conversion device provided with a Ag 3 BiI ₆ film as a photoelectric conversion layer. It is sectional drawing which illustrates the structure of an electronic device. (A) is a diagram showing an X-ray diffraction pattern of the analysis of the photoelectric conversion layer of Example 1, (b) is an X-ray diffraction pattern reported for Ag ₃ BiI _6.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

(First embodiment)
FIG. 1 is a diagram illustrating the structure of the crystal CL included in the film according to the first embodiment. Film according to the present embodiment includes a crystal CL having a composition represented by the general formula _A n _B m _{X z.} A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ . B is one or more selected from the group consisting of Bi, Sb, and La. X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN. Here, (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds. This will be described in detail below.

  The crystal CL includes first ions 140 of elements or element groups included in X. The crystal CL has, for example, a structure in which a plurality of octahedral units 120 each consisting of six first ions 140 share two first ions 140 on the ridge and share each other.

In the following, a crystal having a composition represented by the general formula A _n B _m X _z is referred to as a crystal CL. A film including the crystal CL according to the present embodiment is referred to as a film FL.

  The film FL according to the present embodiment is a crystalline film, for example, a polycrystalline film. Further, the film FL according to the present embodiment may include an amorphous phase.

In the general formula A _n B _m X _z , (n, m) is (1, 1), (3, 1), (1, 3), (2, 1), (7, 1), (9, 1 ), (5, 1), (1, 2), (5, 3), and the like. However, for n and m, an error caused by a defect or a different phase included in the crystal CL is allowed. That is, (n _i , m _i ) is changed to (1,1), (3,1), (1,3), (2,1), (7,1), (9,1), (5,1 ), (1,2) and (5,3), in the general formula A _n B _{m Xz} , n _i / m _i × 0.8 ≦ n / m ≦ n _i / m _i × 1 .2 is preferable, and more preferably n _i / m _i × 0.9 ≦ n / m ≦ n _i / m _i × 1.1. For example, the case where 0.8 ≦ n / m ≦ 1.2 is satisfied corresponds to the case where (n, m) is approximately (1, 1). The case where 2.4 ≦ n / m ≦ 3.6 is satisfied corresponds to the case where (n, m) is approximately (3,1). In the general formula A _n B _m X _z , n / m ≧ 0.8 is preferable, and n / m ≧ 0.9 is more preferable.

  An example of the crystal structure of the crystal CL will be described below. However, the crystal CL is not limited to the crystal structure described below. Further, the film FL according to the present embodiment may include not only the crystal CL but also a crystal having another crystal structure. The crystal CL may contain impurities, defects, and the like. The composition and structure of the crystal CL can be confirmed using an X-ray diffraction method or the like.

The crystal CL includes a first ion of an element or element group included in X, a second ion of an element or element group included in A, and a third ion of an element included in B. That is, the crystal CL is an ionic crystal. The element contained in X represents F, Cl, Br, and I, and the element group contained in X represents CN and SCN. Moreover, the element contained in A shows each of Ag, Cu, In, Na, and K, and the element group contained in A shows NH ₄ . And the element contained in B has shown each of Bi, Sb, and La. The first ion is a monovalent anion, the second ion is a monovalent cation, and the third ion is a trivalent cation.

Thus, in the general formula _A n _B m _{X z,} in theory electrical neutrality is obtained when the n + 3m = z holds. However, compositional deviation due to inclusion of impurities, defects, etc. may occur. That is, in the general formula A _n B _m X _z , (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds, and (n + 3m) × 0.9 ≦ z ≦ (n + 3m) × 1.1 It is more preferable to hold.

  FIG. 2 is a diagram illustrating the structure of the octahedral unit 120. This figure shows an example in which the cation 142 is located at the center. The cation 142 is a second ion or a third ion. In the octahedral unit 120, the six first ions 140 are located at the apexes of the regular octahedron. The first ions 140 included in one octahedral unit 120 may be included in another octahedral unit 120 at the same time.

  FIG. 3 is a diagram showing a laminated structure of plate-like units. The crystal CL includes a plurality of octahedral units 120. As described above, the plurality of octahedral units 120 have a structure in which the two first ions 140 on the edge are shared and connected to each other. In this structure, the octahedral unit 120 is coupled to another adjacent octahedral unit 120. Specifically, one octahedral unit 120b shares two first ions 140 on the edge with another adjacent octahedral unit a. In other words, the first ridge of the octahedral unit 120a and the first ridge of the octahedral unit 120b coincide. Here, the octahedral unit 120 a and the octahedral unit 120 b do not share three or more first ions 140. That is, the octahedral unit 120a and the octahedral unit 120b do not coincide with each other. However, the crystal CL may partially include a plurality of octahedral units 120 that share only one vertex or a plurality of octahedral units 120 that share a plane with each other due to defects or the like. good.

  Further, the octahedral unit 120b shares two first ions 140 on the ridge with another adjacent octahedral unit 120c. The octahedral unit 120c is an octahedral unit 120 different from the octahedral unit 120a, but the octahedral unit 120b and the octahedral unit 120c are also adjacent to each other. And the 1st edge of octahedron unit 120c and the 2nd edge of octahedron unit 120b correspond. The second ridge of the octahedral unit 120b is a ridge different from the first ridge of the octahedral unit 120b. Further, the octahedral unit 120 c and the octahedral unit 120 b do not share three or more first ions 140. As described above, the octahedral unit 120 is connected to the plurality of adjacent octahedral units 120 while sharing only the two first ions 140 on the ridges. One octahedral unit 120 can be combined with a maximum of 12 other octahedral units 120.

  The crystal CL includes a plate-like unit 100 in which a plurality of octahedral units 120 are connected by sharing the two first ions 140 on the edge as described above. Specifically, the crystal CL includes a structure in which a plurality of plate-like units 100 are stacked. In each plate-like unit 100, one octahedral unit 120 is bonded and shared with six first octahedral units 120 adjacent to each other in the plane and two first ions 140 on the respective edges. However, the octahedral unit 120 located at the end of the plate-like unit 100 may be bonded only to five or less octahedral units 120.

  In the plurality of octahedral units 120 included in the plate unit 100, one of the eight surfaces constituting the octahedron corresponds to the first surface of the plate unit 100. Of the eight surfaces, the other surface parallel to the one surface coincides with the second surface of the plate unit 100. That is, the thickness of the plate unit 100 corresponds to the distance between two parallel surfaces of the octahedral unit 120. Further, the plurality of octahedral units 120 constituting the plate unit 100 are arranged in the same direction.

  The crystal CL includes a first octahedral unit 120 in which no ions are present at the center, a second octahedral unit 120 in which a second ion of an element or element group included in A is positioned at the center, and an element included in B. And a third octahedral unit 120 centered on the third ion. Each plate-like unit 100 may have a structure in which only one of the first octahedral unit 120, the second octahedral unit 120, and the third octahedral unit 120 is connected. Of these, two types of octahedral units 120 may be connected to each other, or three types of octahedral units 120 may be connected to each other.

  FIG. 3 shows a case where the crystal CL includes a plurality of types of plate-like units. Specifically, in the example of the figure, the plurality of stacked plate-like units 100 include a first plate-like unit 101 and a second plate-like unit 102. The crystal CL includes a structure in which the first plate-like units 101 and the second plate-like units 102 are alternately stacked. In the first plate unit 101, the ratio of the first octahedral unit 120 is v ′, the ratio of the second octahedral unit 120 is a ′, and the ratio of the third octahedral unit 120 is b ′. Here, v ′, a ′, and b ′ are ratios to the total number of octahedron units 120 constituting the first plate-like unit 101, respectively. Further, in the second plate-like unit 102, the ratio of the first octahedral unit 120 is v ″, the ratio of the second octahedral unit 120 is a ″, and the ratio of the third octahedral unit 120 is b. ''. Here, v ″, a ″, and b ″ are ratios to the total number of octahedron units 120 constituting the second plate unit 102, respectively. That is, a ′ + b ′ + v ′ = 1 and a ″ + b ″ + v ″ = 1. Further, a ′ + a ″ +3 (b ′ + b ″) = 2 holds because the charge neutrality is satisfied. Here, 2 on the right side is that the number of the first ions 140 that are monovalent anions existing in the first plate unit 101 and the second plate unit 102 is the same as the octahedral unit 120. Derived from. The ratio represented by a ′: b ′: v ′ and the ratio represented by a ″: b ″: v ″ are different from each other. That is, a ′: b ′: v ′ = a ″: b ″: v ″ does not hold.

  In the plurality of first plate-like units 101, the arrangement of the first octahedral unit 120, the second octahedral unit 120, and the third octahedral unit 120 may be different from each other. Further, in the plurality of second plate units 102, the arrangement of the first octahedral unit 120, the second octahedral unit 120, and the third octahedral unit 120 may be different from each other. The stacking order of the first plate unit 101 and the second plate unit 102 is not particularly limited.

  (N, m), (a ′, b ′, v ′), (a ″, b ″, v ″) for each type of crystal CL, the content of A in the crystal CL (at%), and Table 1 shows an example of the relationship of the B content (at%) in the crystal CL. In addition, the content rate (at%) of A and the content rate (at%) of B are content rates with respect to the sum total of the substance amount of A and B, respectively.

  Note that (n, m), (a ′, b ′, v ′), and (a ″, b ″, v ″) are not limited to the examples shown in Table 1. In addition, (n, m), (a ′, b ′, v ′) and (a ″, b ″, v ″) shown in Table 1 are theoretical values, and defects included in the crystal Errors due to out-of-phase etc. are allowed. Then, (a ′, b ′, v ′) and (a ″, b ″, v ″) may be opposite to each other.

  In Table 1, in types 1 and 2, at least one of v ′ and v ″ is 0.1 or less. In Type 4, at least one of a ′ and a ″ is 0.1 or less. In types 1, 2, 3, and 5, at least one of b ′ and b ″ is 0.1 or less. Each type will be specifically described below. However, in the following, the first plate unit 101 and the second plate unit 102 are determined so that a ′ <a ″ is satisfied or a ′ = a ″ and b ′ <b ″ are satisfied. And

In Type 1, 2.4 ≦ n / m ≦ 3.6 is established. Further, b ′ ≦ 0.1 and v ″ ≦ 0.1 are established. Further, 0.4 ≦ a ′ / v ′ ≦ 0.6 and 1.6 ≦ a ″ / b ″ ≦ 2.4 hold. For this type, the composition represented by the general formula _A n _B m _{X z,} for example, _Ag 3 BiI _6, and _{an In} 3 BiI ₆ and the like.

In type 2, 1.6 ≦ n / m ≦ 2.4 holds. Further, b ′ ≦ 0.1 and v ″ ≦ 0.1 are established. Further, 0.2 ≦ a ′ / v ′ ≦ 0.3 and 1.2 ≦ a ″ / b ″ ≦ 1.8 hold. For this type, the composition represented by the general formula _A n _B m _{X z,} for example include _Ag 2 BiI ₅ and _Cu 2 BiI _5.

  In Type 3, 1.2 ≦ n / m ≦ 1.8 is established. Further, b ′ ≦ 0.1 holds. Further, 0.4 ≦ a ′ / v ′ ≦ 0.6, 0.6 ≦ a ″ / b ″ ≦ 0.9, and 1.6 ≦ b ″ / v ″ ≦ 2.4. It holds.

In Type 4, 0.8 ≦ n / m ≦ 1.2 is established. Further, a ′ ≦ 0.1 holds. Furthermore, 0.3 ≦ b ′ / v ′ ≦ 0.4, 1.6 ≦ a ″ / b ″ ≦ 2.4, and 0.8 ≦ b ″ / v ″ ≦ 1.2. It holds. For this type, the composition represented by the general formula _A n _B m _{X z,} for example AgBiI ₄ and CuBiI ₄ and the like.

In type 5, 0.4 ≦ n / m ≦ 0.6 holds. Further, b ′ ≦ 0.1 holds. Further, 0.1 ≦ a ′ / v ′ ≦ 0.2, 0.2 ≦ a ″ / b ″ ≦ 0.3, and 1.6 ≦ b ″ / v ″ ≦ 2.4. It holds. For this type, the composition represented by the general formula _A n _B m _{X z,} for example AgBi ₂ I ₇ and the like.

  A specific example is given about the diffraction peak obtained when the film | membrane FL is measured by X-ray diffraction. First, as a first example, when A is Ag, B is Bi, X is I, and 2.4 ≦ n / m ≦ 3.6, the maximum diffraction peak is 25 ° ≦ 2θ ≦. It preferably appears in the range of 35 °.

  As a second example, when A is Cu, B is Bi, X is I, and 0.8 ≦ n / m ≦ 1.2, the maximum diffraction peak is 25 ° ≦ 2θ ≦ 35 °. It preferably appears in the range of

For the X-ray diffraction measurement of the film FL, for example, an X-ray diffractometer (manufactured by Rigaku Corporation, RIGAKU Rad B-system) can be used, and the measurement conditions can be as follows.
(Measurement condition)
X-ray source: Cu Kα
X-ray wavelength: 1.5405 mm, 1.5443 mm
Reading width: 0.02 °
Scanning speed: 5 deg / min
Measurement range: 2θ = 10 to 70 °
Measurement temperature: room temperature

An example of a manufacturing method of the film FL including the crystal CL will be described below. This manufacturing method includes a step of forming a precursor film, a step of drying, and a step of heat treatment. In the step of forming the precursor film, a precursor film including one or more elements or element groups A, B, and X and a solvent is formed. In the drying step, the precursor film is dried at the first temperature. In the heat treatment step, the precursor film is heat treated at a second temperature higher than the first temperature. As described above, A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ . B is one or more selected from the group consisting of Bi, Sb, and La. X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN. Crystal CL included in the film FL obtained by the present method has a composition represented by the general formula _A n _B m _{X z,} holds the (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2. This will be described in detail below.

  The crystal CL of the film obtained by this method includes, for example, the first ions of the element or element group contained in X as described above, and each of the octahedron units each consisting of six first ions has two on the edge. The first ions are shared and connected to each other.

  In this method, the step of forming the precursor film and the step of drying may be performed in this order, or the step of forming the precursor film and at least a part of the step of drying may be performed simultaneously. The heat treatment step is performed after the drying step.

In the step of forming the precursor film, for example, a solution containing A, B, X, and a solvent is applied onto the substrate. Examples of the method for applying the solution on the substrate include wet methods such as a spin coating method, an ink jet method, and a spray coating method. In this case, the step of forming the precursor film and the step of drying may be performed at the same time. That is, part of the solvent may be volatilized during the process of forming the precursor film. In the case of using these methods, specifically, a solution is prepared by dissolving or dispersing a material containing at least one of A, B, and X in a solvent. Then, the solution is applied to the substrate. A, B, and materials containing at least one of X is a compound e.g. represented by the general formula AX and BX _3. The solution can be obtained by dissolving or dispersing a plurality of materials in a solvent.

  The solution may be heated so that the material is sufficiently dissolved. Further, the substrate may be warmed before applying the solution onto the substrate. By doing so, it is possible to prevent a precipitate from being generated in the solution before it spreads wet on the substrate. Moreover, you may perform application | coating of the solution on a base material, heating a base material at temperature lower than 2nd temperature. By doing so, volatilization of the solvent can be promoted.

  The solvent may be one or more selected from a first solvent such as dimethyl sulfoxide (DMSO), dimethylformamide (DMF), γ-butyrolactone (GBL), 1-N-methyl-2-pyrrolidone (NMP). preferable. In addition, the solvent has additives such as hydrogen iodide and 1,8-diiodooctane for the purpose of improving the solubility of the precursor and suppressing the crystallization and obtaining a crystal thin film having a uniform and flat surface. Can be introduced.

  In addition, in order to obtain a crystal thin film having a uniform, flat and large crystal grain size, the first solvent is used during the step of forming the precursor film using the solution of the first solvent or the step of drying. You may process to substitute with a 2nd solvent. The treatment for replacing the first solvent with the second solvent is, for example, a method in which the second solvent which is a poor solvent for the crystal CL is dropped on the undried thin film, or the undried thin film is used as the second solvent. This can be done by dipping. As the second solvent, alcohols such as ethanol, isopropyl alcohol, methoxypropylene, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, esters such as ethyl acetate and propylene glycol monomethyl ether acetate, ketones such as methyl ethyl ketone, isobutyl methyl ketone and acetone , Ethers such as diethyl ether and diproprene ether, aromatic solvents such as toluene, xylene and chlorobenzene, heterocyclic aromatic solvents such as tetrahydrofuran, and the like.

  Moreover, it is also possible to use it as a 1st solvent by adding the additive which improves the solubility of crystal | crystallization CL, such as hydrogen iodide and 1,8- diiodooctane, to a 2nd solvent.

  In the step of forming the precursor film, when the amount of A contained in the precursor film is p, the amount of B is q, and the amount of X is r, (p + 3q) × 0.8 ≦ r ≦ ( It is preferable to form the precursor film so that p + 3q) × 1.2 is satisfied, and it is more preferable to form the precursor film so that (p + 3q) × 0.9 ≦ r ≦ (p + 3q) × 1.1 is satisfied. preferable. By doing so, the film FL containing the crystal CL can be obtained efficiently. The relationship between the substance amounts of A, B, and X contained in the precursor film can be adjusted according to, for example, the charging ratio of the material when preparing the above solution.

  As described above, the drying step is performed at the first temperature. The first temperature is, for example, room temperature, specifically 15 ° C. or higher and 30 ° C. When performing the process to dry, heating, 1st temperature is 50 degreeC or more and less than 100 degreeC, for example. Although the time required for the drying step is not particularly limited, for example, it can be performed by allowing the substrate on which the precursor film is formed to stand for 1 to 60 minutes. In the drying step, drying is preferably performed until the content of the solvent in the precursor film is 50% by weight or less, and more preferably 45% by weight or less.

  After the drying step, a step of heat-treating the precursor film is performed to obtain the film FL. As described above, the heat treatment step is performed at the second temperature. Although it will not specifically limit if 2nd temperature is higher than 1st temperature, For example, it is 100 degreeC or more and less than 200 degreeC. Note that the drying step need not be performed at a constant temperature, that is, the first temperature may vary. In that case, the maximum temperature of the drying step is set lower than the second temperature. Further, the heat treatment may be performed in multiple stages at a plurality of temperatures. Although the time which heats a precursor film | membrane is not specifically limited, For example, it is 1 minute or more and 60 minutes or less.

  In the method according to this embodiment, the color of the precursor film before the heat treatment step is different from the color of the film FL obtained after the heat treatment step. Here, it can be visually confirmed whether or not the colors of the films are different. It can also be said that the films having wavelengths different from each other by 100 nm or more that take the maximum peak of the absorption spectrum of light have different colors.

  The step of forming the precursor film may be performed, for example, by immersing a film containing one of B and A and X in a solution containing the other of A and B and X. A film containing one of B and A and X can be formed on the substrate by, for example, the wet method or the vapor deposition method described above. For the solution containing the other of A and B and X, for example, the same solvent as described above can be used.

  Further, the manufacturing method of the film FL is not limited to the above, and the precursor material obtained by removing the solvent from the solution containing A, B, X, and the solvent as described above is vaporized. It can also be formed by a vapor deposition method for forming a film on a substrate.

FIG. 4A is a diagram showing a Tauc plot of a UV-Vis spectrum obtained by measuring an Ag ₃ BiI ₆ film by ultraviolet-visible (UV-Vis) spectroscopy. FIG. 4B is a diagram showing a Tauc plot of a UV-Vis spectrum obtained by measuring an In ₃ BiI ₆ film by ultraviolet-visible (UV-Vis) spectroscopy. The evaluated Ag ₃ BiI ₆ film is a polycrystalline film containing crystals having a composition of Ag ₃ BiI ₆ , and is a film containing crystals CL corresponding to the type 1 described above. The In ₃ BiI ₆ film is a polycrystalline film containing a crystal having a composition of In ₃ BiI ₆ and a film containing a crystal CL corresponding to the type 1 described above.

The Ag ₃ BiI ₆ film is formed by performing a step of forming a precursor film by applying a solution in which AgI and BiI ₃ are dissolved in a solvent onto a substrate, further drying, and performing a heat treatment. Obtained. The In ₃ BiI ₆ film is formed by performing a step of forming a precursor film by applying a solution in which InI and BiI ₃ are dissolved in a solvent onto a substrate, and further performing a drying step and a heat treatment step. Obtained.

From the results shown in FIGS. 4A and 4B, the energy band gap (Eg) of Ag ₃ BiI ₆ is 1.83 eV, and the energy band gap of In ₃ BiI ₆ is 1.75 eV. I understand. That is, it can be seen that both the Ag ₃ BiI ₆ film and the In ₃ BiI ₆ film have semiconductor characteristics.

FIG. 5 is a diagram showing a photoluminescence (PL) spectrum of an Ag ₃ BiI ₆ film. The spectrum shown in this figure was obtained with an excitation wavelength of 532 nm. As shown in the figure, the Ag ₃ BiI ₆ film emits fluorescence. The peak wavelength of about 720 nm in the spectrum is considered to correspond to the band gap energy.

FIG. 6 is a diagram showing the attenuation profile of the photoluminescence of the Ag ₃ BiI ₆ film. The attenuation profile in this figure was obtained with an excitation wavelength of 532 nm and an emission wavelength of 712 nm. From the results shown in this figure, it was found that the Ag ₃ BiI ₆ film emits light in two modes having different decay times. The decay times for the two modes were τ ₁ = 10.3 ns and τ ₂ = 203.8 ns, respectively. Thus, the light emission of the Ag ₃ BiI ₆ film included a mode with a long decay time of 203.8 ns. Therefore, it can be seen that the Ag ₃ BiI ₆ film can be suitably used as a photoelectric conversion material.

  Next, the operation and effect of this embodiment will be described. According to the present embodiment, since the lead or the like is not included, the toxicity is low, and a film that can be used electrically and optically can be obtained.

(Second Embodiment)
FIG. 7 is a cross-sectional view illustrating the structure of the photoelectric conversion device 20 according to the second embodiment. The photoelectric conversion device 20 includes a first electrode 210, a second electrode 220, and a photoelectric conversion layer 230. The photoelectric conversion layer 230 is located between the first electrode 210 and the second electrode 220. The photoelectric conversion layer 230 includes the film FL according to the first embodiment. That is, the photoelectric conversion layer 230 has a film FL including crystals CL having a composition represented by the general formula _A n _B m _{X z.} Here, A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ . B is one or more selected from the group consisting of Bi, Sb, and La. X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN. Further, (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds. This will be described in detail below.

  The crystal CL includes, for example, first ions of elements or element groups included in X, and has a structure in which a plurality of octahedral units are connected to each other by sharing two first ions on the ridge. Each of a plurality of octahedral units is composed of six first ions.

  Examples of the substrate 200 include transparent members such as glass and plastic. In particular, the substrate 200 is more preferably a flexible translucent resin substrate. Thereby, the apparatus manufacture by a roll to roll system is realizable.

  Examples of organic materials for forming a flexible translucent resin substrate include acrylic ester, methacrylic ester, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate, polychlorinated. Mention may be made of vinyl (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), nylon (Ny), aromatic polyamide, polyetheretherketone, polysulfone, polyethersulfone, polyimide, and polyetherimide. it can. As the light-transmitting resin substrate, a substrate formed of these organic materials can be used as a single layer or by stacking two or more layers. The translucent resin substrate may be an unstretched film or a stretched film. Although the thickness of the base material 200 is not specifically limited, It is preferable that they are 0.1 mm or more and 5.0 mm or less.

  The first electrode 210 is, for example, a transparent conductive oxide. Examples of the transparent conductive oxide include fluorine-doped tin oxide (FTO), indium tin oxide (ITO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), and niobium-doped titanium oxide ( One or more of TNO), indium zinc oxide (IZO), and the like can be used. Moreover, you may use what laminated | stacked aluminum dope zinc oxide (AZO) and Ag alternately (AZO / Ag / AZO). Thereby, light can be introduced into the photoelectric conversion layer 230 and power can be efficiently extracted from the photoelectric conversion layer 230. The first electrode 210 can be formed by, for example, a sputtering method. A commercially available substrate with the first electrode 210 may be used as the base material 200 and the first electrode 210.

  The thickness of the first electrode 210 is preferably 0.01 μm or more and 10.0 μm or less, and more preferably 0.05 μm or more and 1.0 μm or less. By doing so, since the sheet resistance can be reduced while maintaining the high light transmittance of the first electrode 210, a high fill factor can be obtained.

  Examples of the second electrode 220 include carbon, gold, platinum, palladium, rhodium, tungsten, molybdenum, tantalum, titanium, niobium, indium tin oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, and gallium-doped zinc oxide. One or more selected from the group consisting of can be used. The second electrode 220 may be an alloy including any of gold, platinum, palladium, rhodium, tungsten, molybdenum, tantalum, titanium, and niobium, for example. The thickness of the second electrode 220 is not particularly limited, but is preferably 0.01 μm or more and 2.0 μm or less. The second electrode 220 can be formed by, for example, a vacuum deposition method, a sputtering method, or the like.

  The photoelectric conversion layer 230 includes the film FL described in the first embodiment. The photoelectric conversion layer 230 may be a single layer or may be composed of a plurality of layers. The thickness of the photoelectric conversion layer 230 is preferably 10 nm to 10,000 nm, more preferably 20 nm to 900 nm, and still more preferably 100 nm to 800 nm. By doing so, it is possible to prevent performance deterioration due to defects and peeling, and to obtain high photoelectric conversion efficiency.

The photoelectric conversion device 20 may further include an electron transport layer between the photoelectric conversion layer 230 and the first electrode 210. In the example of this figure, the photoelectric conversion device 20 further includes a dense electron transport layer 231 between the photoelectric conversion layer 230 and the first electrode 210. The dense electron transport layer 231 includes, for example, titanium oxide (TiO ₂ or the like), tungsten oxide (WO ₂ , WO ₃ , W ₂ O ₃ or the like), zinc oxide (ZnO), strontium titanate (SrTiO ₃ or the like), aluminum oxide ( One or more metal oxides such as Al ₂ O ₃ ) can be used. The dense electron transport layer 231 preferably has a light-transmitting property. The thickness of the dense electron transport layer 231 is not particularly limited, but is preferably 5 nm to 100 nm, more preferably 5 nm to 50 nm, and still more preferably 10 nm to 40 nm. By doing so, leakage can be suppressed. The dense electron transport layer 231 can be formed using, for example, an atomic layer deposition (ALD) method.

  In the example of this figure, the photoelectric conversion device 20 further includes a porous electron transport layer 232 between the dense electron transport layer 231 and the photoelectric conversion layer 230. The porous electron transport layer 232 has a porous structure. Although it does not necessarily restrict | limit with a porous structure, It is preferable that a granular material, a linear body, etc. aggregate and have a porous property as a whole. Here, examples of the shape of the linear body include a needle shape, a tube shape, and a column shape. The pore size of the porous structure is preferably nanoscale. A substance similar to that constituting the photoelectric conversion layer 230 may enter the pores of the porous electron transport layer 232. In that case, it can be said that the mixed layer of the porous electron transport material constituting the porous electron transport layer and the photoelectric conversion material constituting the photoelectric conversion layer is a layer serving as both the porous electron transport layer and the photoelectric conversion layer. When the porous electron transport layer 232 has a porous structure, the active surface area of the photoelectric conversion layer 230 can be increased, the photoelectric conversion efficiency can be improved, and the electron collection efficiency can be improved. When the photoelectric conversion device 20 includes the above mixed layer, the thickness including the mixed layer can be regarded as the thickness of the photoelectric conversion layer 230.

Examples of the porous electron transport layer 232 include titanium oxide (TiO _{2 and the} like), tungsten oxide (WO ₂ , WO ₃ , W ₂ O _{3 and the} like), zinc oxide (ZnO), niobium oxide (Nb ₂ O _{5 and the} like), One or more of tantalum oxide (Ta ₂ O ₅ etc.), yttrium oxide (Y ₂ O ₃ etc.), strontium titanate (SrTiO ₃ etc.), etc. can be used. In addition, when using a semiconductor, the donor may be doped. When the porous electron transport layer 232 is titanium oxide (TiO ₂ or the like), the crystal form of titanium oxide is preferably anatase type. The porous electron transport layer 232 preferably has translucency. The thickness of the porous electron transport layer 232 is preferably 10 nm or more and 2000 nm or less, and more preferably 20 nm or more and 1500 nm or less. If it does so, the electron collection efficiency from the photoelectric converting layer 230 can be improved. The porous electron transport layer 232 can be formed, for example, by a non-vacuum process such as a spin coating method or a screen printing method and a firing process as necessary. Note that the photoelectric conversion device 20 may include only one of the dense electron transport layer 231 and the porous electron transport layer 232 as the electron transport layer.

In the example of this figure, the photoelectric conversion device 20 further includes a hole transport layer 233 between the photoelectric conversion layer 230 and the second electrode 220. The hole transport layer 233 includes selenium, iodide such as copper iodide (CuI), cobalt complex such as layered cobalt oxide, CuSCN, molybdenum oxide (MoO ₃ etc.), nickel oxide (NiO etc.), 4CuBr · 3S (C ₄ H ₉ ), organic hole transport material, and the like. Examples of the organic hole transport material include polythiophene derivatives such as poly-3-hexylthiophene (P3HT) and polyethylenedioxythiophene (PEDOT), 2,2 ′, 7,7′-tetrakis- (N, N-di-), and the like. fluorene derivatives such as p-methoxyphenylamine) -9,9′-spirobifluorene (spiro-MeO-TAD), carbazole derivatives such as polyvinylcarbazole, poly [bis (4-phenyl) (2,4,6-tri Phenylphenyl) amine] (PTAA) and the like, diphenylamine derivatives, polysilane derivatives, polyaniline derivatives and the like. The thickness of the hole transport layer 233 is not particularly limited, but is preferably 0.01 μm or more and 10 μm or less.

  The hole transport layer 233 is preferably formed by a non-vacuum process such as an evaporation method, a spray method, a dip method, or a spin coating method. Specifically, the dip method can be performed by repeating the operation of dropping the solution of the material for forming the hole transport layer 233 and leveling the surface. In the specific vacuum process, an organic solvent such as n-propyl sulfide or chlorobenzene can be used as the solvent.

  Note that the structure of the photoelectric conversion device 20 is not limited to the structure shown in FIG. For example, the photoelectric conversion device 20 may not include at least one of the dense electron transport layer 231, the porous electron transport layer 232, and the hole transport layer 233.

  Moreover, the photoelectric conversion apparatus 20 may be sealed with a sealing material (not shown). By doing so, the durability of the photoelectric conversion device 20 can be improved and the lifetime can be increased. Examples of the sealing material include glass and resin.

  The photoelectric conversion device 20 can be manufactured, for example, by the method described below. First, the first electrode 210 is formed on one surface of the substrate 200 and patterned by photolithography or the like as necessary. Then, the porous electron transport layer 232, the dense electron transport layer 231, the photoelectric conversion layer 230, and the hole transport layer 233 are formed in this order on the first electrode 210, and the second electrode 220 is further formed. The second electrode 220 can be formed in a predetermined pattern using a mask or the like.

  The energy conversion efficiency of the photoelectric conversion device 20 according to the present embodiment is not particularly limited, but may be, for example, 0.1% or more, and more preferably 3% or more.

  The photoelectric conversion device 20 may further include a circuit for extracting power from the photoelectric conversion layer 230, a control unit, and the like.

FIG. 8 is a diagram illustrating a result of observing a cross section of a photoelectric conversion device including the Ag ₃ BiI ₆ film with an electron microscope. In the photoelectric conversion device shown in this figure, FTO, porous TiO ₂ (m-TiO ₂ ), Ag ₃ BiI ₆ , PTAA, and Au are laminated on a glass substrate. The Ag ₃ BiI ₆ film was formed by the same method as the Ag ₃ BiI ₆ film described in the first embodiment. From this _figure, it Ag 3 BiI ₆ is formed in a film shape, and it can be seen _Ag 3 BiI ₆ film is a polycrystalline film.

FIG. 9 is a diagram showing the relationship between the energy levels of m-TiO ₂ , Ag ₃ BiI ₆ , and PTAA. From the result of separately evaluating the Ag ₃ BiI ₆ film by UPS, the energy level at the upper end of the valence band of Ag ₃ BiI ₆ is −1.25 eV. Moreover, since the band gap of Ag ₃ BiI ₆ is 1.83 eV from the result shown in FIG. 4, the energy level at the lower end of the conduction band of Ag ₃ BiI ₆ is 0.58 eV. On the other hand, the energy level of the lower end of the conduction band of m-TiO ₂ is 0.5 eV, and the energy level of HOMO (maximum occupied orbit) of PTAA is −0.55 eV. Therefore, electrons generated by photoexcitation in Ag ₃ BiI ₆ are extracted to the m-TiO ₂ side, and holes are extracted to the PTAA side. That is, the Ag ₃ BiI ₆ film is a photoelectric conversion layer, m-TiO ₂ is an electron transport layer, and PTAA. Functions well as a hole transport layer.

FIGS. 10A to 10D are diagrams illustrating the distribution of characteristics of a photoelectric conversion device including an Ag ₃ BiI ₆ film as a photoelectric conversion layer. 10A to 10D are histograms showing results obtained by producing and evaluating a plurality of photoelectric conversion devices as shown in FIG. Specifically, FIG. 10A shows a short circuit current density J _sc [mA / cm ² ], FIG. 10B shows an open circuit voltage V _oc [V], FIG. 10C shows a fill factor (FF), and FIG. 10 (d) shows the distribution of energy conversion efficiency PCE [%]. From this figure, it can be seen that good photoelectric conversion characteristics can be obtained in a photoelectric conversion device including an Ag ₃ BiI ₆ film as a photoelectric conversion layer.

  The film FL can be used for various optical devices and electronic devices. Examples of the optical device including the film FL include a wavelength conversion element, an optical sensor, and a light emitting element in addition to the photoelectric conversion device. An example of the electronic device including the film FL is a field transistor such as a field effect transistor. The film FL may be doped with impurities.

  FIG. 11 is a cross-sectional view illustrating the configuration of the electronic device 30. In the figure, an example of a field transistor is shown. The electronic device 30 includes a substrate 300, a channel layer 310, a source 320, a drain 330, an insulating layer 340, and a gate 350. The channel layer 310 includes the film FL. The base material 300 is, for example, a metal or a semiconductor substrate such as silicon. The insulating layer 340 is silicon oxide or the like. The gate 350 is a metal electrode.

  The channel layer 310 is formed on the substrate 300, and the insulating layer 340 is formed on the channel layer 310 by patterning using a sputtering method or the like. Further, the source 320 and the drain 330 are formed in the channel layer 310 by performing impurity doping using, for example, a sputtering method. Then, the gate 350 is formed on the insulating layer 340 by a vacuum deposition method using a mask or the like, and the electronic device 30 is obtained.

  Hereinafter, the present embodiment will be described in detail with reference to examples. In addition, this embodiment is not limited to description of these Examples at all.

(Production of photoelectric conversion device)
<Example 1>
In Example 1, a mixed layer (120 nm) of FTO (1 μm), TiO ₂ (20 nm), m-TiO ₂ and Ag ₃ BiI ₆ on a 2 cm square glass (1.7 mm) as follows. , Ag ₃ BiI ₆ (650 nm), PTAA (50 nm),
A solar cell element (photoelectric conversion device) having a cell structure in which Au (50 nm) was formed in this order was produced in the atmosphere.

  Specifically, first, the surface of a glass substrate with a fluorine-doped tin oxide (FTO) film (Asahi Glass Co., Ltd.) was subjected to UV ozone treatment for 10 minutes. Here, glass corresponds to the base material described in the embodiment, and FTO corresponds to the first electrode.

Then, using titanium tetraisopropoxide (TTIP) (manufactured by Japan Advanced Chemicals Inc.) as a raw material, a dense electron transport layer made of TiO ₂ is repeated 330 cycles deposition reaction at 120 ° C. by a plasma ALD method (film thickness 20 nm). The plasma ALD method was performed using a plasma generator (Model OZONE manufactured by For all) under the condition of an output of 80 W.

Subsequently, after the surface of the obtained dense electron transport layer was subjected to UV ozone treatment for 10 minutes, 3 g of α-terpinol and 9 g of ethanol were added to 3 g of a TiO ₂ nanoparticle solution (18NRT manufactured by JGC Catalysts & Chemicals Co., Ltd.). Solution A was applied by spin coating. The spin coating method was performed at 5000 rpm for 30 seconds so that the dry film thickness was 120 nm. After application of the solution A, baking was performed at 500 ° C. for 2 hours to form mesoporous TiO ₂ (m-TiO ₂ ) (corresponding to a porous electron transport layer).

Then, warm the substrate m-TiO ₂ was formed on 110 ° C., it was attached to the room temperature spin coater. The solution was then dissolved AgI and BiI ₃ in a solvent B1 a (0.5 mL) over a porous electron transport layer was coated by spin coating (6000 rpm, 120 seconds). The concentration of AgI in the solution B1 was 3 molar, and the concentration of BiI ₃ was 1 molar. That is, r ₁ = p ₁ + 3q ₁ was established, where the amount of Ag contained in the resulting precursor film was p ₁ , the amount of Bi was q ₁ , and the amount of I was r ₁ . Further, dimethyl sulfoxide (DMSO) was used as a solvent in the solution B1.

  In the process of spin coating, the temperature of the substrate was lowered to about room temperature at the stage where the solution B1 was applied to the substrate and rotated to spread the solution B1 on the substrate. Thereafter, the solvent was volatilized while the substrate was continuously rotated to form a precursor film. As the substrate continued to rotate, the solvent evaporated. Thus, the step of forming the precursor film and the step of drying were performed. That is, in this example, the drying process was performed at room temperature.

The obtained precursor film was orange. In the step of drying, AgI, seems BiI ₃ and DMSO interacted. In the drying step, drying was performed until the content of the solvent in the precursor film was 45% by weight or less. When the substrate on which the precursor film was formed was heated using a hot plate at 110 ° C. for 10 minutes, the color of the sample changed to black. Further, heat treatment was performed at 130 ° C. for 10 minutes to obtain a photoelectric conversion layer. Note that the same material as that constituting the photoelectric conversion layer entered the pores of the porous electron transport layer to form a mixed layer. And the thickness of the mixed layer which served as the porous electron carrying layer and the photoelectric converting layer was 120 nm, and the film thickness from the upper surface of the porous electron carrying layer among the photoelectric converting layers was 650 nm. That is, the total film thickness of the photoelectric conversion layer was 770 nm.

  Next, a hole transport layer solution in which 30 mg of poly [bis (4-phenyl) (2,4,6-triphenylmethyl) amine] (PTAA) as a hole transport material was dissolved in chlorobenzene (2 mL) was prepared. . This hole transport layer solution was applied onto the photoelectric conversion layer by a spin coating method (2000 rpm, 20 seconds) to form a hole transport layer (film thickness 50 nm).

  Subsequently, Au was formed into a film by a vapor deposition method on the positive hole transport layer, and the 2nd electrode (film thickness of 50 nm) was formed, and the photoelectric conversion apparatus was obtained.

  In addition, the film thickness of each formed film was measured by observing the cross section of a photoelectric conversion apparatus with an electron microscope.

<Example 2>
In Example 2, in place of the solution B1, except that the CuI and BiI ₃ using a solution B2 was dissolved in a solvent, on the Glass (1.7 mm) of 2cm square in the same manner as in Example 1, FTO A cell structure in which (1 μm), TiO ₂ (20 nm), a mixed layer of m-TiO ₂ and CuBiI ₄ (120 nm), CuBiI ₄ (650 nm), PTAA (50 nm), and Au (50 nm) are formed in this order. The photoelectric conversion device was prepared under the atmosphere.

Concentration of CuI in the solution B2 was 1 molar concentration of BiI ₃ was 1 molar. That is, r ₂ = p ₂ + 3q ₂ is established when the amount of Cu contained in the resulting precursor film is p ₂ , the amount of Bi is q ₂ , and the amount of I is r ₂ . Further, DMSO was used as a solvent in the solution B2. Also in this example, as in Example 1, a change in the color of the sample due to the heat treatment was observed.

<Comparative Example 1>
In Comparative Example 1, except for the points described below, FTO (1 μm), TiO ₂ (20 nm), m-TiO ₂ and MaPbI are formed on 2 cm square glass (1.7 mm) in the same manner as in Example 1. _A photoelectric conversion device having a cell structure in which a mixed layer (120 nm) with No. ₃ (120 nm), MaPbI ₃ (650 nm), PTAA (50 nm), and Au (50 nm) were formed in this order was manufactured in the atmosphere. That is, in Comparative Example 1, in place of the solution B1, using a solution B3 was dissolved MaI and PbI ₂ in a solvent. Further, the substrate before spin coating with the solution B3 was heated to 70 ° C., and the heat treatment was performed at 70 ° C. for 10 minutes and further at 80 ° C. for 10 minutes. Ma represents CH ₃ NH ₃ .

The concentration of MaI in solution B3 was 2 molar, and the concentration of PbI ₂ was 1 molar. Further, DMSO was used as a solvent in the solution B3.

<Comparative example 2>
In Comparative Example 2, in place of the solution B3, except that a solution B4 was dissolved MaI and SnI ₂ in a solvent, on the Glass (1.7 mm) of 2cm square in the same manner as in Comparative Example 1, FTO (1 μm), TiO ₂ (20 nm), a mixed layer of m-TiO ₂ and MaSnI ₃ (120 nm), MaSnI ₃ (650 nm), PTAA (50 nm), and Au (50 nm) are formed in this order. The photoelectric conversion device was prepared under the atmosphere.

The concentration of MaI in solution B4 was 1 molar, and the concentration of SnI ₂ was 1 molar. Further, DMSO was used as a solvent in the solution B4.

  The photoelectric conversion devices and photoelectric conversion layers of each Example and Comparative Example were evaluated as follows. The evaluation results are summarized in Table 2.

(Evaluation of crystal composition and crystal structure)
The composition and structure of crystals contained in the photoelectric conversion layer were evaluated. The evaluation was performed using an X-ray diffraction method on the exposed surface of the photoelectric conversion layer after the photoelectric conversion layer was formed and before the hole transport layer solution was applied. For the evaluation, an X-ray diffraction apparatus (RIGAKU Rad B-system, manufactured by Rigaku Corporation) was used, and the measurement conditions were as follows.
(Measurement condition)
X-ray source: Cu Kα
X-ray wavelength: 1.5405 mm, 1.5443 mm
Reading width: 0.02 °
Scanning speed: 5 deg / min
Measurement range: 2θ = 10 to 70 °
Measurement temperature: room temperature

12A is a diagram showing an X-ray diffraction pattern obtained by analyzing the photoelectric conversion layer of Example 1. FIG. FIG. 12B is an X-ray diffraction pattern reported for Ag ₃ BiI ₆ . Incidentally, FIG. 12 (b) is a pattern that has been reported in Non-Patent Document 1, a data obtained for powdery _Ag 3 BiI _6. In both patterns of FIG. 12A and FIG. 12B, there is a maximum peak in the vicinity of 2θ = 39 °. Further, in the pattern of FIG. 12A and the pattern of FIG. 12B, many peak positions such as 2θ = 13 °, 24 °, 42 °, 43 °, and the like coincide. Thus, the crystals contained in the photoelectric conversion layer of Example 1, was found to have a composition represented by Ag ₃ BiI _6. In addition, the photoelectric conversion layer of Example 1 has a structure in which a plurality of octahedral units composed of six I (iodine) ions (corresponding to first ions) share two I ions on the ridge and share each other. It was found to have a film containing a type 1 crystal CL as described in the embodiment.

Similarly, the crystals contained in the photoelectric conversion layer of Example 2 was found to have a composition represented by CuBiI _4. In addition, the photoelectric conversion layer of Example 2 is also a film having a structure in which a plurality of octahedral units composed of six anions (equivalent to iodine ions and first ions) are connected by sharing two anions on the ridge with each other. In addition, it was found to have a film including the type 4 crystal CL as described in the embodiment. The maximum diffraction peak in the X-ray diffraction pattern obtained by analyzing the photoelectric conversion layer of Example 2 appeared in the range of 25 ° ≦ 2θ ≦ 35 °.

  Moreover, the photoelectric conversion layer of Example 1 and Example 2 was a polycrystalline film.

On the other hand, it was found that the crystals contained in the photoelectric conversion layers of Comparative Examples 1 and 2 had a perovskite structure. That is, although octahedron units composed of six anions are included, the octahedron units are linked by sharing only one anion at the top. The composition of crystals contained in the photoelectric conversion layer of Comparative Example 1 was MaPbI ₃ , and the composition of crystals contained in the photoelectric conversion layer of Comparative Example 2 was MaSnI ₃ .

  While the photoelectric conversion layer of Comparative Example 1 contains lead, the photoelectric conversion layers of Example 1 and Example 2 do not contain lead and can be said to have low toxicity.

(Evaluation of conversion efficiency)
After the photoelectric conversion device was left in the atmosphere for 2 hours, the current-voltage characteristics (IV characteristics) of the photoelectric conversion device were measured. From the obtained current-voltage characteristics, the energy conversion efficiency (PCE) of the photoelectric conversion device was determined. As a result, as shown in Table 2, high energy conversion efficiency could be realized in the photoelectric conversion devices of Example 1 and Example 2.

(Evaluation of atmospheric stability)
The difference between the color of the surface of the photoelectric conversion device immediately after the evaluation of the conversion efficiency and the color of the surface of the photoelectric conversion device after being left in the atmosphere for 2 days was visually observed. As a result, the case where a change from black to yellow (yellowing fading, yellowing deterioration) was observed was evaluated as x, and the case where it was not observed was evaluated as ◯. As a result, as shown in Table 2, Example 1 and Example 2 had high atmospheric stability, and Comparative Example 1 and Comparative Example 2 had low atmospheric stability.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

Hereinafter, examples of the reference form will be added.
1-1. Includes a crystal having a composition represented by the general formula _A n _B m _{X z,}
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
A film that satisfies (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2.
1-2. 1-1. In the membrane described in
A film satisfying n / m ≧ 0.8.
1-3. 1-1. Or 1-2. In the membrane described in
The crystal is
Including a first ion of an element or group of elements contained in X,
A film having a structure in which a plurality of octahedral units each consisting of six first ions are connected to each other by sharing two first ions on a ridge.
1-4. 1-3. In the membrane described in
The crystal is
A first octahedral unit having no ions in the center;
A second octahedral unit centered on a second ion of an element or group of elements contained in A;
And a third octahedral unit in which a third ion of an element contained in B is located at the center.
1-5. 1-4. In the membrane described in
The crystal is a film in which the plurality of octahedral units include a plate-like unit in which two first ions on a ridge are shared and connected to each other.
1-6. 1-5. In the membrane described in
The crystal is a film including a structure in which a plurality of the plate-like units are stacked.
1-7. 1-6. In the membrane described in
The plurality of plate units include the first plate unit and the second plate unit,
In the first plate unit, the ratio of the first octahedron unit to the total number of octahedron units constituting the first plate unit is v ′, and the ratio of the second octahedron unit is a. ', The ratio of the third octahedral unit is b',
The ratio of the first octahedral unit to the total number of octahedral units constituting the second plate unit in the second plate unit is v ″, and the ratio of the second octahedral unit is a ″, when the ratio of the third octahedral unit is b ″,
The ratio represented by a ′: b ′: v ′ and the ratio represented by a ″: b ″: v ″ are different from each other,
The crystal is a film including a structure in which the first plate unit and the second plate unit are alternately stacked.
1-8. 1-7. In the membrane described in
A membrane in which at least one of v ′ and v ″ is 0.1 or less.
1-9. 1-7. Or 1-8. In the membrane described in
A film in which at least one of a ′ and a ″ is 0.1 or less.
1-10. 1-1. To 1-9. In the membrane according to any one of
A film that satisfies 0.8 ≦ n / m ≦ 1.2 or 2.4 ≦ n / m ≦ 3.6.
1-11. 1-1. To 1-10. In the membrane according to any one of
A is Ag, B is Bi, X is I,
2.4 ≦ n / m ≦ 3.6,
A film in which the maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when measured by X-ray diffraction.
1-12. 1-1. To 1-10. In the membrane according to any one of
A is Cu, B is Bi, X is I,
0.8 ≦ n / m ≦ 1.2,
A film in which the maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when measured by X-ray diffraction.
1-13. 1-1. To 1-12. In the membrane according to any one of
A film that is a polycrystalline film.
1-14. 1-1. To 1-13. An optical device comprising the film according to any one of the above.
1-15. 1-1. To 1-13. An electronic device comprising the film according to any one of the above.
2-1. A first electrode;
A second electrode;
A photoelectric conversion layer located between the first electrode and the second electrode,
The photoelectric conversion layer has a film containing a crystal having a composition represented by the general formula _An B _m x _z ,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
A photoelectric conversion device that satisfies (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2.
2-2. 2-1. In the photoelectric conversion device described in
A photoelectric conversion device that satisfies n / m ≧ 0.8.
2-3. 2-1. Or 2-2. In the photoelectric conversion device described in
The crystal is
Including a first ion of an element or group of elements contained in X,
A photoelectric conversion device having a structure in which a plurality of octahedral units each including six first ions are connected to each other by sharing two first ions on a ridge.
2-4. 2-3. In the photoelectric conversion device described in
The crystal is
A first octahedral unit in which no ion is located in the center;
A second octahedral unit centered on a second ion of an element or group of elements contained in A;
And a third octahedral unit in which a third ion of an element contained in B is located at the center.
2-5. 2-4. In the photoelectric conversion device described in
The photoelectric conversion device, wherein the crystal includes a plate-like unit in which the plurality of octahedral units are connected to each other by sharing the two first ions on the ridge.
2-6. 2-5. In the photoelectric conversion device described in
The crystal is a photoelectric conversion device including a structure in which a plurality of the plate-like units are stacked.
2-7. 2-6. In the photoelectric conversion device described in
The plurality of plate units include the first plate unit and the second plate unit,
In the first plate unit, the ratio of the first octahedron unit to the total number of octahedron units constituting the first plate unit is v ′, and the ratio of the second octahedron unit is a. ', The ratio of the third octahedral unit is b',
The ratio of the first octahedral unit to the total number of octahedral units constituting the second plate unit in the second plate unit is v ″, and the ratio of the second octahedral unit is a ″, when the ratio of the third octahedral unit is b ″,
The ratio represented by a ′: b ′: v ′ and the ratio represented by a ″: b ″: v ″ are different from each other,
The crystal is a photoelectric conversion device including a structure in which the first plate unit and the second plate unit are alternately stacked.
2-8. 2-7. In the photoelectric conversion device described in
A photoelectric conversion device in which at least one of v ′ and v ″ is 0.1 or less.
2-9. 2-7. Or 2-8. In the photoelectric conversion device described in
A photoelectric conversion device in which at least one of a ′ and a ″ is 0.1 or less.
2-10. 2-1. To 2-9. In the photoelectric conversion device according to any one of
A photoelectric conversion device that satisfies 0.8 ≦ n / m ≦ 1.2 or 2.4 ≦ n / m ≦ 3.6.
2-11. 2-1. To 2-10. In the photoelectric conversion device according to any one of
A is Ag, B is Bi, X is I,
2.4 ≦ n / m ≦ 3.6,
A photoelectric conversion device in which a maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when the film is measured by X-ray diffraction.
2-12. 2-1. To 2-10. In the photoelectric conversion device according to any one of
A is Cu, B is Bi, X is I,
0.8 ≦ n / m ≦ 1.2,
A photoelectric conversion device in which a maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when the film is measured by X-ray diffraction.
2-13. 2-1. To 2-12. In the photoelectric conversion device according to any one of
A photoelectric conversion device, wherein the film is a polycrystalline film.
2-14. 2-1. To 2-13. In the photoelectric conversion device according to any one of
A photoelectric conversion device having an energy conversion efficiency of 0.1% or more.
3-1. A method for producing a film containing crystals,
Forming a precursor film each containing one or more elements or element groups A, B, and X, and a solvent;
Drying the precursor film at a first temperature;
Heat-treating the precursor film at a second temperature higher than the first temperature,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
It said crystal has a composition represented by the general formula _A n _B m _{X z,}
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 A method for producing a film.
3-2. 3-1. In the method for producing a film according to claim 1,
A method for producing a film satisfying n / m ≧ 0.8.
3-3. 3-1. Or 3-2. In the method for producing a film according to claim 1,
The crystal is
Including a first ion of an element or group of elements contained in X,
A method of manufacturing a film having a structure in which a plurality of octahedral units each composed of six first ions are connected by sharing two first ions on a ridge.
3-4. 3-3. In the method for producing a film according to claim 1,
The crystal is
A first octahedral unit in which no ion is located in the center;
A second octahedral unit centered on a second ion of an element or group of elements contained in A;
A method for producing a film including the third octahedral unit in which a third ion of an element contained in B is located at the center.
3-5. 3-4. In the method for producing a film according to claim 1,
The method for producing a film, wherein the crystal includes a plate-like unit in which the plurality of octahedral units are connected by sharing two first ions on a ridge.
3-6. 3-5. In the method for producing a film according to claim 1,
The crystal is a method of manufacturing a film including a structure in which a plurality of the plate-like units are stacked.
3-7. 3-6. In the method for producing a film according to claim 1,
The plurality of plate units include the first plate unit and the second plate unit,
In the first plate unit, the ratio of the first octahedron unit to the total number of octahedron units constituting the first plate unit is v ′, and the ratio of the second octahedron unit is a. ', The ratio of the third octahedral unit is b',
The ratio of the first octahedral unit to the total number of octahedral units constituting the second plate unit in the second plate unit is v ″, and the ratio of the second octahedral unit is a ″, when the ratio of the third octahedral unit is b ″,
The ratio represented by a ′: b ′: v ′ and the ratio represented by a ″: b ″: v ″ are different from each other,
The method for producing a film, wherein the crystal includes a structure in which the first plate unit and the second plate unit are alternately stacked.
3-8. 3-7. In the method for producing a film according to claim 1,
A method for producing a film, wherein at least one of v ′ and v ″ is 0.1 or less.
3-9. 3-7. Or 3-8. In the method for producing a film according to claim 1,
A method for producing a film, wherein at least one of a ′ and a ″ is 0.1 or less.
3-10. 3-1. To 3-9. In the method for producing a film according to any one of
A method for producing a film in which 0.8 ≦ n / m ≦ 1.2 or 2.4 ≦ n / m ≦ 3.6.
3-11. 3-1. To 3-10. In the method for producing a film according to any one of
A is Ag, B is Bi, X is I,
2.4 ≦ n / m ≦ 3.6,
A method for producing a film, wherein the maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when the film is measured by X-ray diffraction.
3-12. 3-1. To 3-10. In the method for producing a film according to any one of
A is Cu, B is Bi, X is I,
0.8 ≦ n / m ≦ 1.2,
A method for producing a film, wherein the maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when the film is measured by X-ray diffraction.
3-13. 3-1. To 3-12. In the method for producing a film according to any one of
A method for producing a film, wherein the film is a polycrystalline film.
3-14. 3-1. To 3-13. In the method for producing a film according to any one of
When the amount of A contained in the precursor film is p, the amount of B is q, and the amount of X is r,
(P + 3q) × 0.8 ≦ r ≦ (p + 3q) × 1.2 A method for manufacturing a film.
3-15. 3-1. To 3-14. In the method for producing a film according to any one of
The method for producing a membrane, wherein the solvent is one or more selected from the group consisting of dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, and 1-N-methyl-2-pyrrolidone.
3-16. 3-1. To 3-15. In the method for producing a film according to any one of
In the step of forming the precursor film, a film manufacturing method in which a solution containing A, B, X, and the solvent is applied onto a substrate.
3-17. 3-1. To 3-16. In the method for producing a film according to any one of
The method for producing a film, wherein the first temperature is room temperature.
3-18. 3-1. To 3-16. In the method for producing a film according to any one of
The manufacturing method of a film | membrane whose said 1st temperature is 50 degreeC or more and less than 100 degreeC.
3-19. 3-1. To 3-18. In the method for producing a film according to any one of
The method for producing a film, wherein the second temperature is 100 ° C. or higher and lower than 200 ° C.
3-20. 3-1. To 3-19. In the method for producing a film according to any one of
In the drying step, the film is dried until the content of the solvent in the precursor film is 50% by weight or less.
3-21. 3-1. To 3-20. In the method for producing a film according to any one of
The method for producing a film, wherein the color of the precursor film before the heat treatment step is different from the color of the film obtained after the heat treatment step.

20 photoelectric conversion device 30 electronic device 100 plate unit 101 first plate unit 102 second plate unit 120 octahedron unit 140 first ion 142 cation 200 base material 210 first electrode 220 second electrode 230 photoelectric conversion layer 231 Dense electron transport layer 232 Porous electron transport layer 233 Hole transport layer 300 Base material 310 Channel layer 320 Source 330 Drain 340 Insulating layer 350 Gate

Claims (16)

Includes a crystal having a composition represented by the general formula _A n _B m _{X z,}
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds,
The crystal is
Including a first ion of an element or group of elements contained in X,
A film having a structure in which a plurality of octahedral units each consisting of six first ions are connected to each other by sharing two first ions on a ridge. The membrane of claim 1, wherein
The crystal is
A first octahedral unit having no ions in the center;
A second octahedral unit centered on a second ion of an element or group of elements contained in A;
And a third octahedral unit in which a third ion of an element contained in B is located at the center. The membrane of claim 2,
The crystal includes a plate-like unit in which the plurality of octahedral units are connected by sharing the two first ions on the edge with each other,
The crystal is a film including a structure in which a plurality of the plate-like units are stacked. The membrane according to any one of claims 1 to 3,
A film that satisfies 0.8 ≦ n / m ≦ 1.2 or 2.4 ≦ n / m ≦ 3.6. The membrane according to any one of claims 1 to 4,
A is Ag, B is Bi, X is I,
2.4 ≦ n / m ≦ 3.6,
A film in which the maximum diffraction peak appears in a range of 25 ° ≦ 2θ ≦ 35 ° when measured by X-ray diffraction.   An optical device comprising the film according to claim 1.   An electronic device comprising the film according to claim 1. A first electrode;
A second electrode;
A photoelectric conversion layer located between the first electrode and the second electrode,
The photoelectric conversion layer is a photoelectric conversion device including the film according to any one of claims 1 to 5. A method for producing a film containing crystals,
Forming a precursor film each containing one or more elements or element groups A, B, and X, and a solvent;
Drying the precursor film at a first temperature;
Heat-treating the precursor film at a second temperature higher than the first temperature,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
It said crystal has a composition represented by the general formula _A n _B m _{X z,}
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 holds,
The crystal is
Including a first ion of an element or group of elements contained in X,
A method for producing a film, wherein a plurality of octahedral units each consisting of six first ions each have a structure in which two first ions on a ridge are shared and connected to each other. In the manufacturing method of the film | membrane of Claim 9,
A method for producing a film, wherein 0.8 ≦ n / m ≦ 1.2 or 2.4 ≦ n / m ≦ 3.6. In the manufacturing method of the film | membrane of Claim 9 or 10,
The method for producing a membrane, wherein the solvent is one or more selected from the group consisting of dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, and 1-N-methyl-2-pyrrolidone. In the manufacturing method of the film according to any one of claims 9 to 11,
In the step of forming the precursor film, a film manufacturing method in which a solution containing A, B, X, and the solvent is applied onto a substrate. In the manufacturing method of the film according to any one of claims 9 to 12,
In the drying step, the film is dried until the content of the solvent in the precursor film is 50% by weight or less. Includes a crystal having a composition represented by the general formula _A n _B m _{X z,}
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
A film satisfying (n + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 and n / m ≧ 0.8. A first electrode;
A second electrode;
A photoelectric conversion layer located between the first electrode and the second electrode,
The photoelectric conversion layer is a photoelectric conversion device having the film according to claim 14. A method for producing a film containing crystals,
Forming a precursor film each containing one or more elements or element groups A, B, and X, and a solvent;
Drying the precursor film at a first temperature;
Heat-treating the precursor film at a second temperature higher than the first temperature,
A is one or more selected from the group consisting of Ag, Cu, In, Na, K, and NH ₄ ;
B is one or more selected from the group consisting of Bi, Sb, and La,
X is one or more selected from the group consisting of F, Cl, Br, I, CN, and SCN,
It said crystal has a composition represented by the general formula _A n _B m _{X z,}
(N + 3m) × 0.8 ≦ z ≦ (n + 3m) × 1.2 and n / m ≧ 0.8.