JP2017107836A - Transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film which can be produced at a low temperature and can be easily patterned.SOLUTION: A transparent conductive film has cations and anions, 20 mol% or more and 90 mol% or less of the cations are cations of 13-15 group elements, and 40 mol% or more and 100 mol% or less of the anions are anions of group 17 elements.SELECTED DRAWING: None

Description

  The present invention relates to a transparent conductive film.

  At present, transparent conductive films are used for various applications such as electrical appliances, and thus are a material that greatly contributes to improving the standard of living from a technical viewpoint in modern society. Conventionally, indium tin oxide, fluorine-doped tin oxide, and the like mainly using metal oxides such as tin oxide and zinc oxide are known as transparent conductive films.

  For example, as described in Patent Document 1, tin oxide as a transparent conductive film is coated on a substrate with a soluble tin compound as a precursor of tin oxide, and is usually subjected to a heat treatment at 500 ° C. or higher. It can be manufactured by decomposing the body. Furthermore, in order to dissolve and remove tin oxide by etching or the like, it is known to use a strong acid or a reducing agent.

JP 63-275187 A

  In the conventional metal oxide as described in Patent Document 1, since a high temperature is required for production, the substrate to be deposited is limited to one having high heat resistance, and a glass plate is mainly used. . However, since the glass plate is heavy and cannot be said to be easy to process, there are problems such as a low degree of freedom from the viewpoint of the selectivity of its shape. On the other hand, if a material such as plastic can be used as the substrate, it is possible not only to reduce the weight but also to increase the degree of freedom from the viewpoint of shape selectivity. Therefore, a transparent conductive member that does not require a high-temperature atmosphere in the manufacturing process is required so that plastic or the like can be used as a substrate.

  In addition, metal oxides typified by tin oxide require strong acids and reducing agents for etching for patterning, etc., but it is safe to remove and dissolve them using a less reactive solvent. And from the viewpoint of simplicity of work.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a transparent conductive film that can be manufactured at a low temperature and can be easily patterned.

  As a result of diligent research and experiments to solve the above-described problems of the prior art, the present inventors have found that the above-described problems can be solved by using a transparent conductive film having a specific composition. It has come.

That is, the present invention is as follows.
(1) A cation and an anion are included, and 20 mol% or more and 90 mol% or less of the cation is a cation of a group 13 to 15 element, and 40 mol% or more and 100 mol% or less of the anion is a group 17 element. A transparent conductive film which is an anion.
(2) The transparent conductive film according to (1), wherein 25 mol% or more and 80 mol% or less of the cation is a cation of a group 13 to 15 element.
(3) The transparent conductive film according to (1) or (2), wherein the cation of the Group 13 to 15 element includes a cation of an element selected from the group consisting of Group 15 elements.
(4) The transparent conductive film according to any one of (1) to (3), wherein the cation of the Group 13 to 15 element is a bismuth cation.
(5) The transparent conductive film according to any one of (1) to (4), wherein the cation of the Group 13 to 15 element includes a cation having an electron configuration of s ² d ¹⁰ p ⁰ .
(6) The transparent conductive film according to any one of (1) to (5), wherein 60 mol% or more of the anion is an anion of a Group 17 element.
(7) The transparent conductive film according to any one of (1) to (6), wherein the Group 17 element is any one selected from the group consisting of Cl, Br, and I.
(8) The transparent conductive film according to any one of (1) to (7), wherein 60 mol% or more and 100 mol% or less of the anion is a chlorine anion.
(9) The transparent conductive material according to any one of (1) to (8), wherein a counter cation of the cation of the Group 13 to 15 element is 10 mol% to 80 mol% of the cation. film.
(10) The transparent conductive film according to (9), wherein the counter cation includes a single element cation.
(11) The transparent conductive film according to (10), wherein the single element cation includes a cation of an element selected from the group consisting of Group 1 elements to Group 3 elements.
(12) The transparent conductive film according to (10) or (11), wherein the single element cation contains an element selected from the group consisting of Cs, Rb, K and Na.
(13) The main material of the transparent conductive film is Cs ₃ Bi ₂ X ₉ , where X is I, Br, or Cl, according to any one of (10) to (12) Transparent conductive film.
(14) The transparent conductive film according to any one of (9) to (12), wherein the counter cation includes a molecular cation.
(15) The transparent conductive film according to (14), wherein the molecular cation includes an organic molecule.
(16) The transparent conductive film according to (15), wherein the organic molecule has 1 to 20 carbon atoms.
(17) The transparent conductive film according to any one of (14) to (16), wherein the molecular cation includes an ammonium group.
(18) The transparent conductive film according to any one of (15) to (17), wherein the organic molecular cation includes a methyl group.
(19) The transparent conductive film according to any one of (15) to (18), wherein the molecular cation includes a methylammonium cation.
(20) The transparent conductive film according to (19), wherein a main material of the transparent conductive film is (CH ₃ NH ₃ ) ₃ Bi ₂ X ₉ , where X is I, Br or Cl.
(21) The transparent conductive film according to any one of (15) to (18), wherein the molecular cation includes a dimethylammonium cation.
(22) The transparent material according to (21), wherein a main material of the transparent conductive film is ((CH ₃ ) ₂ NH ₂ ) ₃ Bi ₂ X ₉ , where X is I, Br or Cl. Conductive film.
(23) The transparent conductive film according to any one of (15) to (17), wherein the molecular cation includes a guanidinium cation.
(24) The transparent conductive film according to (23), wherein a main material of the transparent conductive film is (CH ₆ N ₃ ) ₃ Bi ₂ X ₉ , where X is I, Br or Cl.
(25) The transparent conductive film according to any one of (15) to (18), wherein the organic molecular cation includes a cyclic carbon chain.
(26) The transparent conductive film according to (25), wherein the cyclic carbon chain includes a polycyclic structure.
(27) The transparent conductive film according to (25), wherein the cyclic carbon chain includes an intramolecular crosslinked structure.
(28) The transparent conductive film according to (27), wherein the crosslinked structure of the intramolecular crosslinked structure contains methylene.
(29) The transparent conductive film according to any one of (25) to (28), wherein the cyclic carbon chain is adamantane.
(30) A main material of the transparent conductive film is (C ₁₀ H ₁₅ NH ₃ ) ₃ Bi ₂ X ₉ , wherein X is I, Br or Cl, (25) to (29) The transparent conductive film as described in any one.
(31) The transparent conductive film according to any one of (1) to (30), including a structure in which the anion is coordinated to a cation of the Group 13 to 15 element.
(32) The transparent conductive film according to any one of (1) to (31), wherein at least a part of the anion has a structure coordinated with a plurality of the Group 13 to 15 elements.
(33) The transparent conductive film according to any one of (1) to (32), including a structure in which the Group 13 to 15 element is 6-coordinated to the anion.
(34) The transparent conductive film according to any one of (1) to (33), which has a thickness of 1 nm to 10 cm.
(35) The transparent conductive film according to any one of (1) to (34), which is in contact with the substrate.
(36) The transparent conductive film according to (35), wherein the substrate includes glass.
(37) The transparent conductive film according to (35), wherein the base material includes plastic.
(38) A method for producing the transparent conductive film according to any one of (1) to (37),
A step of dissolving a substance containing a cation and an anion in an aprotic organic solvent to obtain a solution, a step of removing the solvent from the solution to obtain a transparent conductive film precursor, and the transparent conductive film precursor, And maintaining the temperature at 0 ° C. or higher and 400 ° C. or lower to obtain the transparent conductive film.
(39) The transparent conductive film according to any one of (1) to (37), including a step of applying a pressure of 0.1 MPa to 100 MPa to the transparent conductive film after the step of obtaining the transparent conductive film. A method for producing a membrane.
(40) The method for producing a transparent conductive film according to (39), wherein the temperature in the step of applying the pressure is 0 ° C. or higher and 200 ° C. or lower.

  The transparent conductive film according to the present invention can be produced at a low temperature and can be easily patterned.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with various modifications within the scope of the gist.

(Transparent conductive film)
The transparent conductive film of this embodiment contains a cation and an anion, and 20 mol% or more and 90 mol% or less of the cation is a cation of a group 13 to 15 element, and 40 mol% or more and 100 mol% or less of the anion. Is an anion of a Group 17 element. Since it is configured in this manner, the transparent conductive film according to the present embodiment can be manufactured at a low temperature and can be easily patterned.

  The transparent conductive film of this embodiment can be made into a transparent conductive film by including a cation and an anion as constituents as described above, can be manufactured at a low temperature, can be easily patterned, and has a small effective mass. It is advantageous to do. In the present embodiment, “transparent” means that the absorbance at all wavelengths from 650 nm to 900 nm is 40% or less. When the absorbance at any wavelength in the wavelength range from 650 nm to 900 nm exceeds 40%, the darkness is particularly strong due to the darkness of the black color, and it is not transparent. From the viewpoint of less color and transparency, the wavelength at which the absorbance is 40% or less is preferably all wavelengths from 550 nm to 900 nm, more preferably all wavelengths from 450 nm to 900 nm, and 400 nm. More preferably, all wavelengths from 1 to 900 nm. The transparency can be confirmed by measuring the absorbance from the transmission spectrum of the transparent conductive film.

  From the viewpoint of further advantageous for transparency, the light absorption edge of the transparent conductive film of the present embodiment is preferably shorter than 650 nm, more preferably shorter than 550 nm, and shorter than 400 nm. More preferably, it is a wavelength. In the present embodiment, the “light absorption edge” means a band gap absorption edge or an exciton absorption edge of a semiconductor material, and the transmission edge of the transparent conductive film is extrapolated from the background. It can be evaluated by doing. From the viewpoint of being advantageous for transparency, the transparent conductive film of the present embodiment preferably has a large band gap. Specifically, the band gap is preferably 2.0 eV or more, more preferably 2.5 eV or more, and further preferably 3.2 eV or more.

The cations constituting the transparent conductive film of the present embodiment include cations of the 13th to 15th group elements. By including these cations, the effective mass can be reduced. From the viewpoint of reducing the effective mass, a cation having an electronic configuration of s ² d ¹⁰ p ⁰ is particularly preferable. The element selected from the group consisting of Group 14 or Group 15 elements from the viewpoint of being stable against oxidation from the oxidation state in which the electron configuration is s ² d ¹⁰ p ⁰ as the cation electronegativity is smaller And cations of elements selected from the group consisting of Group 15 elements are more preferable. Specific examples of the cation include Ga, In, Tl, Ge, Sn, Pb, Sb, and Bi cations. From the viewpoint of less harmful to the human body, Ga, In, Ge, Sn, and Bi Cations are preferred, and Bi, that is, a bismuth cation, is particularly preferred from the viewpoint of being advantageous in stability against oxidation from an oxidation state in which the electron configuration is s ² d ¹⁰ p ⁰ . The cation of the group 13-15 element is used singly or in combination of two or more.

It is important that the transparent conductive film has a small effective mass of electrons and / or holes. The effective mass of electrons and holes is the mass of electrons and holes when acting in a member, and the effective mass of electrons and holes is required to be small in order to increase the conductivity of the film. . From the viewpoint of setting the electron configuration to s ² d ¹⁰ p ⁰ and reducing the effective mass, among the cations constituting the transparent conductive film, the cation of the group 13-15 element is 20 mol% or more and 90 mol%. It is important that: From the viewpoint, among the cations constituting the transparent conductive film, the cation of the group 13-15 element is preferably 25 mol% or more, and more preferably 30 mol% or more. From the viewpoint that the arrangement of the group 13-15 element cations can be controlled by including a counter cation other than the group 13-15 element cations, among the cations constituting the transparent conductive film, the group 13-15 element cations. Is preferably 80% or less, more preferably 75% or less, and even more preferably 70% or less.

  The cations of the group 13-15 elements in the present embodiment indicate cations corresponding to elements included in the group consisting of groups 13-15 in the periodic table of the new IUPAC included in the transparent conductive film, and these cations The molar ratio is calculated from the sum of the amounts of the respective Group 13 to 15 elements contained in the transparent conductive film.

  The viewpoint that the transparent conductive film of the present embodiment includes a cation other than the cation of the group 13-15 element (hereinafter referred to as counter cation) can control the arrangement of the cation of the group 13-15 element. From the viewpoint of adjusting the carrier density of the material, it is preferable. By controlling the arrangement of the cations of the group 13-15 elements, the effective mass can be reduced and / or the carrier tends to move. The carrier in this embodiment means an electron or a hole. The counter cation can be an organic cation or an inorganic cation. From the viewpoint of thermal stability, inorganic cations are preferred. Further, from the viewpoint of enabling crystallization at a lower temperature, reducing the light absorption in the visible light range, and providing flexibility, a cation containing an organic substance is preferable. Furthermore, the counter cation can be composed of one or more elements or molecules. The counter cation preferably contains any element from Group 1 to Group 12 elements of the new IUPAC. A counter cation is used individually by 1 type or in combination of 2 or more types.

  From the viewpoint of adjusting the carrier density of the transparent conductive film that can control the arrangement of the Group 13 to 15 elements with less hybridization of the counter cation element to the valence band and the conduction band, Of the cations contained in the conductive film, 10 mol% or more is preferable, 25% or more is more preferable, and 35% or more is more preferable. The counter cation is included in the transparent conductive film from the viewpoint that by increasing the content of the group 13-15 element, the density of states due to the group 13-15 element to the valence band and the conduction band can be increased. Of the cations obtained, 80 mol% or less is preferable, and 70 mol% or less is more preferable.

  In this embodiment, it is preferable that an inorganic cation is contained in the counter cation which comprises a transparent conductive film from a viewpoint that thermal stability and manufacture of a raw material are comparatively easy. In addition, from the viewpoint of thermal stability and easy production of raw materials, a cation composed of a single element (hereinafter also referred to as “single element cation”) is included in the counter cation constituting the transparent conductive film. Is preferred. From the above viewpoint, the single element cation contained in the counter cation is preferably contained in an amount of 10 mol% or more, more preferably 20 mol%, further preferably 30 mol%, among the cations constituting the transparent conductive film. Mole% or more is more preferable.

  From the viewpoint that the electronegativity is small and the cationic property is strong and / or the ionic radius is advantageous for the formation of the crystal structure, the transparent conductive film of the present embodiment is from the group consisting of Group 1 elements to Group 3 elements. It preferably includes a single element counter cation of choice. Further, the counter cation of a single element selected from the group consisting of Group 1 elements to Group 3 elements is preferably contained in the cation constituting the transparent conductive film in an amount of 10 mol% or more, more preferably 20 mol%. Preferably, 30 mol% is more preferable, and 40 mol% or more is still more preferable. From the viewpoint that the more the Group 13 to 15 elements, the more advantageous the carrier movement, the cation of a single element selected from the group consisting of Group 1 to Group 3 elements is preferably 80 mol% or less. 70 mol% or less is more preferable, and 65 mol% or less is more preferable.

When the counter cation is a cation consisting of a single element, the s ⁰ electron configuration reduces the mixing of the counter cation element into the valence band and conduction band, and controls the arrangement of group 13-15 element cations. From the standpoint of possible, the single element is preferably any element selected from the group consisting of Group 1 elements to Group 3 elements. In addition, from the viewpoint of delocalizing the electronic state of the arranged group 13-15 element cations by increasing the ionic radius when the electron configuration of s ⁰ is obtained, the single element described above is Any element selected from the group consisting of group elements and group 2 elements is more preferable, and any element selected from the group consisting of group 1 elements is more preferable. Specifically, lithium, potassium, sodium, rubidium, cesium, magnesium, calcium, strontium, barium, scandium, lanthanum, cerium, scandium and the like are preferable, lithium, potassium, sodium, rubidium, cesium, magnesium, calcium, strontium, And barium are more preferable, and an element selected from the group consisting of sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs) is more preferable.

  The counter cation preferably includes a molecular cation. When the counter cation is a molecular cation, the molecular cation is preferably a cation containing an organic substance such as a metal cluster or an organic molecule. It is preferable that the molecular cation contains an ammonium group or an amine group from the viewpoint that the constituent nitrogen element is abundant and is a relatively small cation, and from the same viewpoint, an ammonium group is more preferable. One or a plurality of the ammonium groups and amine groups can be contained in one molecule. Further, from the viewpoint of being able to crystallize at a lower temperature, from the viewpoint of reducing light absorption, and from the viewpoint of being advantageous for the flexibility of the transparent conductive film, the molecular cation is preferably a cation containing an organic substance such as an organic molecule. In the present specification, “a cation containing an organic substance such as an organic molecule” means a molecular cation containing carbon as a constituent element (hereinafter referred to as “organic molecular cation”). Although it does not specifically limit as carbon number of the organic molecule in the said organic molecule cation, From the viewpoint of strengthening the continuity of a Group 13-15 element cation, a viewpoint advantageous to crystallization, a viewpoint advantageous to a softness | flexibility, and transparency From the viewpoint of advantageous properties, it is preferably 1 or more and 20 or less. From the viewpoint of further enhancing the continuity of the group 13-15 element cations, the organic molecule cation preferably has 10 or less carbon atoms. Further, from the viewpoint of being advantageous for flexibility and the viewpoint of being advantageous for transparency, the number of carbon atoms of the organic molecular cation is more preferably 2 or more, and further preferably 7 or more. In addition, the organic molecular cation preferably contains a methyl group from the viewpoint of increasing the dipole moment, which is advantageous for diffusion of the organic molecular cation. From the viewpoint of being particularly advantageous for flexibility, the organic molecular cation preferably has a cyclic carbon chain, and the cyclic carbon chain preferably includes a polycyclic structure and / or has an intramolecular crosslinking structure. The cross-linked structure of the intramolecular cross-linked structure preferably contains a methylene group, and specifically has a norbornene structure and / or an adamantane structure (that is, the cyclic carbon chain is adamantane). More specific examples of such organic molecular cations include norbornene ammonium, adamantane ammonium, and nuclidine.

  A molecular cation is used individually by 1 type or in combination of 2 or more types. Specific examples of the molecular cation include, but are not limited to, ammonium cation, methyl ammonium cation, ethyl ammonium cation, propyl ammonium cation, butyl ammonium cation, pentyl ammonium cation, hexyl ammonium cation, heptyl ammonium cation, octyl ammonium cation, nonane. Ammonium cation, decan ammonium ammonium cation, dimethyl ammonium cation, diethyl ammonium cation, trimethyl ammonium cation, triethyl ammonium cation, aniline cation, formamidium cation, acetamidium cation, guanidinium cation, norbornene ammonium cation, norbornene methyl ammonium cation, Adamantane Nmo cation, adamantanemethyl ammonium cations and isomers thereof, and the like. From the viewpoint of being advantageous for charge transfer, the size of the molecular cation is preferably small. Specifically, ammonium cations, methylammonium cations, formamidine cations, ethylammonium cations, guanidinium cations, and dimethylammonium are more preferable as molecular cations. Furthermore, the weaker the cation conjugation, the smaller the contribution of carbon and / or nitrogen to the valence band and / or the conduction band, and from the viewpoint that the effective mass can be further reduced, the molecular cation includes ammonium cation and methylammonium cation. And dimethylammonium cation is more preferred. In addition, as a molecular cation, the dipole moment of the organic molecular cation is increased, and from the viewpoint of being advantageous for diffusion of the organic molecular cation during crystallization, the methylammonium cation is more preferable, and the dipole moment of the organic molecular cation is relatively high. The dimethylammonium cation is more preferable from the viewpoints of increasing the molecular weight, which is advantageous for diffusion of the organic molecular cation during crystallization, and that the boiling point of the organic molecular cation becomes high and the transparent conductive film becomes stable. Furthermore, from the viewpoint of being advantageous for flexibility and the viewpoint of transparency, norbornene ammonium cation, norbornene methyl ammonium cation, adamantane ammonium ammonium cation, and adamantane methyl ammonium cation are preferable as molecular cations. Moreover, a guanidinium cation is preferable from the viewpoint of being particularly advantageous for transparency.

The anion which comprises the transparent conductive film of this embodiment contains 40 mol% or more and 100 mol% or less of the 17th group element anion with respect to the total amount (100 mol%) of the contained anion. Including 40 mol% or more from the viewpoint that the ionic bondability of the transparent conductive film is increased by containing more Group 17 element anions, which is advantageous for crystal formation, and from the point that impurity levels are not formed between bands. This is very important. From the viewpoint of increasing the ionic bondability of the transparent conductive film, the anion constituting the transparent conductive film preferably contains 60% by mole or more of the Group 17 element, and more preferably 75% or more. Specific group 17 elements are not particularly limited, and examples include iodine (I), bromine (Br), chlorine (Cl), and fluorine (F). From the viewpoint of increasing the band gap and reducing the amount of absorption in the visible light region when the ion binding property is increased, any one selected from the group consisting of bromine, chlorine and fluorine is preferred. On the other hand, when the covalent bond is increased, the electronic state of the cation is more delocalized, and from the viewpoint of being advantageous for carrier transfer, any one of the group 17 elements selected from the group consisting of iodine, bromine, and chlorine One is preferred. In particular, from the viewpoints of increasing the ionic bondability of the transparent conductive film, reducing the amount of absorption in the visible light region, and favoring the movement of carriers, 60 mol% or more and 100 mol% of the anion constituting the transparent conductive film. More preferably, the following is a chlorine anion. The transparent conductive film of the present embodiment may contain a plurality of Group 17 element anions, and the molar ratio of the Group 17 element anions in this case is the amount of Group 17 element contained in the transparent conductive film. Is the sum of Moreover, a molecular anion can also be included as an anion which comprises a transparent conductive film. Here, as the molecular anion, specifically, cyanide anions, thiocyanate anions, thiocyanate anions, selenocyanate anion, BF ₄ ^- anion, PF ₆ ^- anion, CF ₃ COO ^-, etc. anions. A molecular anion is used individually by 1 type or in combination of 2 or more types.

The transparent conductive film of the present embodiment can include crystals. By including crystals, the mobility of electrons and holes can be high, and it is advantageous for operational stability by suppressing large changes in form and physical properties due to crystallization from amorphous, Since the manufacturing method in which crystallization proceeds can be applied, it is preferable that the transparent conductive film includes crystals from the viewpoint of selecting a manufacturing method more suitable for the substrate and the like. From the above viewpoint, it is more preferable that 50 mol% or more of the composition of the transparent conductive film is a crystal, and more preferably 90 mol% or more is a crystal. The crystal contained in the transparent conductive film and the molar ratio of the crystal can be evaluated by various known methods, for example, measurement by X-ray diffraction or the like. The crystal structure of the crystal is preferably a structure in which the electronic state of the group 13-15 element cation is more delocalized from the viewpoint of being advantageous for the movement of electrons, holes, and ions. The delocalized structure is not limited to the following, for example, a structure in which the anion is coordinated to the group 13-15 element cation, and an anion coordinated to the group 13-15 element cation. Is a structure in which at least a part is shared. From the viewpoint of being advantageous for movement of electrons, holes and ions, it is more preferable that the number shared is larger. That is, it is preferable that at least a part of the anion has a structure coordinated with a plurality of the 13th to 15th group element cations. In addition, the coordination number of the group 13-15 element cation to the anion is preferably 5 or more and 8 or less. For example, (CH ₃ NH ₃ ) ₃ Bi ₂ Cl ₉ is preferable because Bi ³⁺ is 6-coordinated to Cl ⁻ and a part of Cl ⁻ has a bond with a plurality of Bi ³⁺ . That is, it is preferable that the group 13-15 element cation includes a structure that is six-coordinated to the anion. The counter cation is preferably present in a crystal site different from Bi in the crystal structure.

The band gap of the main material constituting the transparent conductive film of this embodiment is preferably larger than 1.6 eV from the viewpoint that the smaller the amount of absorption in the visible light region, the more advantageous the transparency. In view of transparency, 1.8 eV or more is more preferable, and 2.0 eV or more is more preferable. In addition, the main material in this specification is a material excluding the dopant. In addition, about the solid solution by a some material, let the material with the largest solid solution ratio be a main material, and when there are two or more materials with the largest solid solution ratio, let the said some material be a main material. For example, (CH ₃ NH ₃ ) ₃ Bi ₂ I ₉ and (CH ₃ NH ₃ ) ₃ Bi ₂ Br ₉ in a 2: 1 solid solution (CH ₃ NH ₃ ) ₃ Bi ₂ (Br ₃ I ₆ ) The main material is assumed to be (CH ₃ NH ₃ ) ₃ Bi ₂ I ₉ .

It is preferable that the transparent conductive film of this embodiment contains a dopant. For example, when the compound is a crystal, the dopant is a cation or a cation contained in the site of the compound, which is different from the cation or anion present at each site constituting the crystal structure. It is an anion. From the viewpoint of improving the carrier density of the transparent conductive film, the valence of the dopant is preferably a cation or anion having a different valence with respect to the cation or anion present at each site constituting the crystal structure of the main material. . More specifically, from the viewpoint of increasing the electron density, the valence of the cation dopant is preferably larger than the cation existing at the site constituting the main material, and the valence of the anion dopant is It is preferable that it is smaller than the anion present at the site constituting the main material. From the viewpoint of increasing the hole density, the valence of the cation dopant is preferably smaller than the cation present at the site constituting the main material, and the valence of the anion dopant is preferably the main material. It is preferable that it is larger than the anion which exists in this site which comprises. The ionic radius of the dopant is preferably a value close to the ionic radius of the cation or anion existing at each crystal structure site of the main material. Here, the dopant having a value close to the ionic radius is, for example, a dopant having an ionic radius of 0.7 to 1.3 times the ionic radius of the cation or anion existing in each crystal structure site of the main material. In view of facilitating doping to a predetermined site, the ionic radius of the dopant is 0.8 times or more the ionic radius of the cation or anion existing at each crystal structure site of the main material. It is preferably less than or equal to twice, more preferably between 0.9 and 1.1 times. Hereinafter, examples in which the main material is A ₃ Bi ₂ X ₉ (A is a monovalent cation, Bi has a valence of 3 and X is a halogen anion) will be given. From the viewpoint that it is advantageous to improve the electron density, dopants of the Bi (III) site are Sn (IV), Ce (IV), Hf (IV), Po (IV), Pr (IV), Tb (IV ), Te (IV), Th (IV), or Zn (IV). In addition, when the cation at the A site is, for example, a group 1 element cation, the dopant at the A site is preferably a group 2 element cation from the viewpoint that it is advantageous for improving the electron density, and the cation at the A site is one. In the case of a valent molecular cation, the dopant is preferably a multivalent molecular cation. More specifically, when the cation at the A site of the main material is a Cs cation, this dopant is preferably a Ba cation, and when the main material A is a monoammonium cation, a diammonium cation, quinuclidine, or the like is preferable. From the standpoint of improving the hole density, the Bi (III) site dopants are Pb (II) cation, Ag (II) cation, Ca (II) cation, Cd (II) cation, Dy (II). ) Cations, Eu (II) cations, Hg (II) cations, Mn (II) cations, Na (I) cations, Pd (II) cations, Sm (II) cations are preferred and are relatively harmless to the human body. In view of being a stable valence cation, Ag (II) cation, Ca (II) cation, Dy (II) cation, Eu (II) cation, Mn (II) cation, Na (I) cation, Pd (II) cation and Sm (II) cation are more preferable. From the viewpoint of improving the hole density, the X site dopant is preferably a group 16 element cation, and specifically, an oxygen anion, a sulfur anion, a selenium anion, a tellurium anion, and the like are preferable.

In the present embodiment, from the viewpoint of excellent heat resistance and physical strength, the main material of the transparent conductive film is preferably Cs ₃ Bi ₂ X ₉ (where X is I, Br or Cl). . From the viewpoint of flexibility and easy crystallization, the main material of the transparent conductive film is (CH ₃ NH ₃ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl), and ((CH ₃ ) ₂ NH ₂ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl) is preferred. Among these, from the viewpoint of increasing the dipole moment of the organic molecular cation and favoring the diffusion of the organic molecular cation during crystallization, (CH ₃ NH ₃ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl) is preferable, the dipole moment of the organic molecular cation becomes relatively large, which is advantageous for diffusion of the organic molecular cation during crystallization, and the boiling point of the organic molecular cation becomes high, so that the transparent conductive film becomes From the viewpoint of stability, ((CH ₃ ) ₂ NH ₂ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl) is preferred. From the viewpoint of flexibility and relatively favorable heat resistance, the main material of the transparent conductive film is (CH ₆ N ₃ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl). It is preferable. From the viewpoint of being particularly advantageous for flexibility and transparency, the main material of the transparent conductive film is (C ₁₀ H ₁₅ NH ₃ ) ₃ Bi ₂ X ₉ (where X is I, Br or Cl, C ₁₀ H ₁₅ is preferably an adamantane structure).

  The interband transition in the main material of the transparent conductive film of this embodiment is preferably an indirect transition or a direct transition. Indirect transition is preferred from the viewpoint of reducing the effective mass by reducing the density of states at the upper end of the valence band and / or the lower end of the conduction band, and from the viewpoint of reducing the extinction coefficient.

  The transparent conductive film of this embodiment can have a single crystal phase or a plurality of crystal phases. From the viewpoint of reducing grain boundaries that can become a resistance in the transparent conductive film, a single crystal phase is preferable. Moreover, it is preferable to have a some crystal phase from a viewpoint which can add a function to a transparent conductive film by including the crystal phase from which a characteristic differs.

  The thickness of the transparent conductive film of the present embodiment is preferably 1 nm or more, more preferably 10 nm or more, and even more preferably 100 nm or more from the viewpoint that the thicker the film is, the more advantageous the conductivity is. On the other hand, 10 cm or less is preferable, 100 micrometers or less is more preferable, and 20 micrometers or less is further more preferable from a viewpoint which can suppress the light absorption amount, so that a film thickness is thin.

(Method for producing transparent conductive film)
Although it does not specifically limit as a manufacturing method of the transparent conductive film of this embodiment, For example, it can pass through a predetermined | prescribed process using the raw material mentioned later. As a raw material of the transparent conductive film of this embodiment, the substance containing the cation element which comprises this transparent conductive film, and the substance containing the anion element which comprises are preferable. In particular, it is preferable to include a step of obtaining a solution by dissolving a substance containing a predetermined cation and an anion in an aprotic organic solvent, and a step of removing the solvent from the solution.

  Specifically, as the raw material of the transparent conductive film of the present embodiment, it is preferable to use the following metals and compounds. Specifically, it is preferable to use metals of Group 13 elements to Group 15 elements and Group 1 elements to Group 3 elements as the metal. More specifically, the metal is gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, lithium, potassium, sodium, rubidium, cesium, magnesium, calcium, strontium, barium, scandium, lanthanum, cerium, And scandium are preferable, and tin, bismuth, potassium, sodium, rubidium, cesium, and the like are more preferable.

  For the above compounds, specifically, it is preferable to use a metal halide, an ammonia compound, a salt of a base and a hydrogen halide as a raw material, from the viewpoint of thermal stability of the raw material and relatively easy production. More preferably, a metal halide is used. Further, from the viewpoint of being advantageous for crystallization of the transparent conductive film, it is preferable to use an ammonia compound or a salt of a base and a hydrogen halide as a raw material of the above compound. The halogen species constituting the metal halide is preferably a group 17 element in the periodic table of the new IPAC, and specifically, fluorine, chlorine, bromine, iodine and the like are preferable. From the viewpoint of increasing the band gap and decreasing the amount of absorption in the visible light region as the ion binding property increases, bromine, chlorine, and fluorine are preferable as the halogen species. On the other hand, iodine, bromine, and chlorine are preferable as the halogen species from the viewpoint of increasing the covalent bond and delocalizing the electronic state of the cation, which is advantageous for carrier movement.

  The metal halide is preferably a group 13-15 metal halide or a halide of an element selected from the group consisting of group 1 elements to group 3 elements.

Among the halides of elements selected from the group consisting of Group 13 to 15 elements, the smaller the cation electronegativity, the more stable is the oxidation from the oxidation state in which the electron configuration is s ² d ¹⁰ p ^0. From a certain viewpoint, a halide containing a Group 14 or Group 15 element is preferable, and a halide containing a Group 15 element is more preferable. Further, from the viewpoint of reducing the effective mass, a halide corresponding to a cation having an electron configuration of s ² d ¹⁰ p ⁰ is preferable. Such halides, specifically, but are not limited to, GaF, GaCl, GaBr, GaI , InF, InCl, InBr, TlF, TlCl, TlBr, TlI, GeF 2, GeCl 2, GeBr 2, GeI ₂ , SnF ₂ , SnCl ₂ , SnBr ₂ , SnI ₂ , PbF ₂ , PbCl ₂ , PbBr ₂ , PbI ₂ , SbF ₃ , SbCl ₃ , SbBr ₃ , SbI ₃ , BiF ₃ , BiCl ₃ , BiBr ₃ , BiBr ₃ From the viewpoint of less harmful to the human body, GaF, GaCl, GaBr, GaI, InF, InCl, InBr, GeF ₂ , GeCl ₂ , GeBr ₂ , GeI ₂ , SnF ₂ , SnCl ₂ , SnBr ₂ , SnI ₂ , BiF ₃ , BiCl ₃ , BiBr ₃ , and BiI ₃ are preferred, and the electron configuration is s ² d ¹⁰ p ^0. BiF ₃ , BiCl ₃ , BiBr ₃ , and BiI ₃ are more preferable from the viewpoint of being advantageous in stability against oxidation from the oxidized state.

Among the halides of elements selected from the group consisting of Group 1 elements to Group 3 elements, the ionic radius when the electron configuration of s ⁰ is increased increases the group 13-15 cation arrangement. From the viewpoint of delocalizing the electronic state, an element selected from the group consisting of Group 1 elements and Group 2 elements is more preferable, and an element selected from the group consisting of Group 1 elements is more preferable. Specifically, lithium iodide, lithium bromide, lithium chloride, sodium iodide, sodium bromide, sodium chloride, potassium iodide, potassium bromide, potassium chloride, rubidium iodide, rubidium bromide, rubidium chloride, iodine Cesium chloride, cesium bromide, cesium chloride and the like.

  Specific examples of the salt of base and hydrogen halide include, but are not limited to, methylamine / hydroiodide, methylamine / hydrobromide, methylamine / hydrochloride, ethylamine / hydroiodide , Ethylamine / hydrobromide, ethylamine / hydrochloride, propylamine / hydroiodide, propylamine / hydrobromide, propylamine / hydrochloride, butylamine / hydroiodide, butylamine / hydrobromide , Butylamine / hydrochloride, pentaamine / hydrogen iodide, pentaamine / hydrobromide, pentaamine / hydrochloride, hexaamine / hydrogen iodide, hexaamine / hydrobromide, hexaamine / hydrochloride, ammonia / iodine Hydrohalide, ammonia / hydrobromide, ammonia / hydrochloride, aniline / hydroiodide, aniline / odor Hydrogen salt, aniline / hydrochloride, dimethylamine / hydrogen iodide, dimethylamine / hydrobromide, dimethylamine / hydrochloride, diethylamine / hydroiodide, diethylamine / hydrobromide, diethylamine / hydrogen chloride Salt, dipropylamine / hydrogen iodide, dipropylamine / hydrobromide, dipropylamine / hydrochloride, trimethylamine / hydrogen iodide, trimethylamine / hydrobromide, trimethylamine / hydrochloride, triethylamine / Hydrogen iodide, triethylamine / hydrobromide, triethylamine / hydrochloride, formamidine / hydrochloride, formamidine / hydroiodide, formamidine / hydrobromide, acetamidine / hydrochloride, acetamidine・ Hydrogen iodide, acetamidine, hydrobromide, guanidine, salt Hydrogen salt, guanidine / hydrogen iodide, guanidine / hydrobromide, imidazole / hydrochloride, imidazole / hydrogen iodide, imidazole / hydrobromide, norborneneamine / hydrogen iodide, norborneneamine / bromide Hydrogen salt, norborneneamine / hydrochloride, norbornenemethylamine / hydroiodide, norbornenemethylamine / hydrobromide, norbornenemethylamine / hydrochloride, adamantaneamine / hydroiodide, adamantaneamine / hydrogen bromide Salts, adamantaneamine / hydrochloride, adamantanemethylamine / hydroiodide, adamantanemethylamine / hydrobromide, and adamantanemethylamine / hydrochloride.

  The transparent conductive film of this embodiment can also be produced by a method that does not use a solvent or a method that uses a solvent. Examples of the method that does not use a solvent include, but are not limited to, a vapor deposition method, a sputtering method, and a solid phase method. From the viewpoint of producing a transparent conductive film having a uniform composition, the transparent conductive film of the present embodiment is a method using a solvent, that is, a method of crystallizing by removing the solvent from a solution in which the raw material is dissolved in the solvent. It is preferable to manufacture a transparent conductive film. That is, the method for producing a transparent conductive film in the present embodiment includes a step of dissolving a substance containing a cation and an anion in an aprotic organic solvent to obtain a solution, and removing the solvent from the solution to obtain a transparent conductive film precursor. A step of obtaining a body (hereinafter, also simply referred to as “precursor”), a step of fixing the precursor as necessary, and then heating at a temperature of 0 ° C. to 400 ° C. to obtain a transparent conductive film; It is preferable to contain. The solvent is preferably an aprotic organic solvent from the viewpoint of being advantageous for dissolving the Group 13-15 metal halide as a raw material. Specifically, dimethylformamide (hereinafter referred to as DMF), dimethyl sulfoxide (hereinafter referred to as DMSO), γ-butyrolactone, and the like are preferable. From the viewpoint of excellent dissolution of the Group 13-15 metal halide, DMF, DMSO is more preferred. From the viewpoint of removing excess solvent and promoting nucleation, it is preferable to form crystals using a poor solvent. Examples of the poor solvent include dimethyl ether, diethyl ether, chlorobenzene, toluene and the like.

  Examples of the method for immobilizing a precursor for producing a transparent conductive film include, but are not limited to, spin coating, spraying, and liquid phase reaction using a solution. The spin coating method is preferred from the viewpoint that the risk of ignition of the raw material solution is small and / or the preparation method is easy to adjust.

  The temperature at which the transparent conductive film is produced from the precursor is preferably 0 ° C. or higher and 400 ° C. or lower from the viewpoint that it can be manufactured with relatively low energy. In addition, the temperature at which the transparent conductive film is produced is 50 ° C. or higher from the viewpoint of advantageous for removing the solvent in the production method using the solvent and advantageous for improving the crystallinity of the transparent conductive film. Is more preferable, and 70 ° C. or higher is even more preferable. On the other hand, from the viewpoint of reducing the heat resistance of the substrate and preventing the decomposition of the material, the temperature at the production of the transparent conductive film is more preferably 350 ° C. or less, further preferably 200 ° C. or less, and plastic. From the viewpoint that it can be used for the substrate, 100 ° C. or lower is particularly preferable.

  The atmosphere for producing the transparent conductive film may be the air or an inert atmosphere. From the viewpoint of easier preparation, it is preferable to produce a transparent conductive film in the air. Moreover, it is preferable to manufacture a transparent conductive film in inert atmosphere from a viewpoint which suppresses formation of a hydrate, an oxide, etc., and a viewpoint which suppresses adsorption | suction of a hydroxyl group.

  The manufacturing method of the transparent conductive film applies a pressure of 0.01 MPa or more and 100 MPa or less to the transparent conductive film after the step of obtaining the transparent conductive film from the viewpoint of improving transparency and / or conductivity. It is preferable to include a process (hereinafter also referred to as a “pressing process”). From the viewpoint of improving transparency and / or conductivity, the pressure applied in this step is more preferably 0.05 MPa or more, further preferably 0.1 MPa or more, and 0.3 MPa or more. Most preferably. Further, from the viewpoint of requiring the resistance of the substrate, the applied pressure is more preferably 50 MPa or less, and further preferably 10 MPa or less. The temperature in the pressing step is preferably 0 ° C. or higher and 350 ° C. or lower, and particularly preferably 50 ° C. or higher and 100 ° C. or lower, from the viewpoint of improving transparency and / or conductivity.

(Use)
The transparent conductive film in this embodiment can be a transparent conductive film for liquid crystal displays, transparent touch panels, electroluminescence, and solar cells. In particular, in the case of use as the above-mentioned portable application, since a substrate advantageous in lightness can be used, a particularly useful transparent conductive film can be obtained. Moreover, the transparent conductive film containing the organic molecular cation in the present embodiment is particularly useful for applications using a flexible base material such as plastic from the viewpoint of improving flexibility and being advantageous in bending resistance.

(Constitution)
It is preferable that the transparent conductive film of this embodiment is contacting the base material from a viewpoint of the intensity | strength improvement of this transparent conductive film. The shape of the substrate is not limited, but a plate shape is preferable from the viewpoint of being advantageous for deposition of the transparent conductive film and being easy to carry. Examples of materials in the substrate include glass such as quartz glass and soda glass, plastics, metals, and compounds. Plastics are preferred from the viewpoint of lighter weight, thermal expansion coefficient is smaller than plastics, heat resistance Glass is preferable from the viewpoint of superiority. In addition, since the material does not need to use a vacuum apparatus and can be deposited even under conditions where crystallization proceeds, there is no need to use sputtering, and the viewpoint that it can be deposited on a compound material with low spatter damage and low heat resistance. Therefore, it is preferable to use a compound as a base material. Examples of the compound include organic compounds and inorganic compounds, and more specifically, metal compounds. Further, from the viewpoint that the physical properties are relatively sensitive to surface defects, the compound is preferably an organic compound or a metal semiconductor. More specifically, the compounds include organic semiconductors, metal oxides, metal sulfides, metal selenides, metal tellurides, metal nitrides, metal phosphides, metal arsenides, and more specifically, Examples include aluminum oxide, silicon oxide, titanium oxide, zinc oxide, gallium nitride, aluminum nitride, copper indium sulfide, copper indium selenide, gallium arsenide, and gallium phosphide.

  Hereinafter, the present embodiment will be described more specifically with specific examples and comparative examples. However, the present embodiment is not limited to these examples and comparative examples unless they exceed the gist thereof. Absent. The physical properties, production conditions, and identification in Examples and Comparative Examples described later were measured and set by the methods shown below.

(Transparent conductive film main material)
X-ray diffraction was performed on the transparent conductive film produced in each example, and the crystal structure was identified from the obtained X-ray diffraction pattern, thereby specifying the main material of the transparent conductive film.
The X-ray diffraction pattern was measured using an X-ray diffractometer (D8 ADVANCE: manufactured by Bruker) under conditions of an X-ray output of 40 kV and 40 mA.

(Interband transition)
The interband transition was obtained from the electronic structure calculation result calculated in CASTEP of Material Studio for each crystal structure. Note each crystal _{structure, Cs 3 Bi 2 I 9 (} ISCD No.:1448),(CH 6 N 3) 3 Bi 2 I 9 (ISCD No.:162078),Cs 3 Bi 2 Br 9 (ISCD No .: 1142), using a _{Cs 3 Bi 2 Cl 9 (ISCD} No.:2067),(CH 3 NH 3) 3 Bi 2 I 9 (ISCD No.:109710), (CH 3 NH 3) 3 Bi 2 I 9 is , Cs ₃ Bi ₂ I ₉ (ISCD No .: 1448) was substituted with (CH ₃ NH ₃ ) ⁺ for Cs ^+, and a crystal structure subjected to structure optimization was used.

(Effective mass ratio of electrons)
The effective mass ratio of electrons was calculated from the following formula for each main material.
(Effective mass ratio of electrons) = (Effective mass of electrons of the transparent conductive film main material) / (Static mass of electrons)
(Effective mass of electrons of transparent conductive film main material) = (converted Planck constant) ² / (curvature of conduction band bottom band)
The curvature of the conduction band lower end band was calculated using the lower end of the conduction band of the electronic structure calculation result calculated by Material Studio CASTEP under the above conditions.

(Deposition temperature)
The heating temperature required for forming a transparent conductive film using solutions 1 to 5 described later was defined as the film formation temperature.

(Etching property)
The etching property was evaluated as “good” when the transparent conductive film was rubbed with a cotton swab dipped in DMF, and “x” when it could not be peeled off.

(Film thickness)
The film thickness was measured using a stylus-type film thickness meter (P-6 type, manufactured by Tencor), and an average film thickness of 0.5 mm between the portion where the transparent conductive film was deposited on the substrate and the portion where the transparent conductive film was not deposited. It was calculated from the difference.

(transparency)
For transparency, the transparent conductive film deposited on the quartz plate was measured with a spectrophotometer (U4100, manufactured by Hitachi, Ltd.) at a scan rate of 300 nm / min to evaluate the absorbance, and the wavelength was from 450 nm to 900 nm. When the absorbance is 40% or less at all wavelengths, the wavelength from 450 nm to 650 nm has an absorbance greater than 40%, and the absorbance at all wavelengths from 650 nm to 900 nm is 40%. In the following cases, it was marked with ◯, and when there was a wavelength with a wavelength greater than 40% at a wavelength from 650 nm to 900 nm, it was marked with ×.

(Flexibility)
The flexibility was evaluated as ◯ when the main material contained an organic molecular cation, and ◎ when the organic molecular cation contained an organic molecule having a polycyclic structure and / or an intramolecular crosslinking structure.

  As shown below, in Examples 1 to 9 and Comparative Example 1, a composition (solution) containing a predetermined cation and anion was prepared, and a transparent conductive film was formed using the composition. Furthermore, the physical properties of the transparent conductive film of each example were evaluated.

<Example 1>
DMSO was used as a solvent, and 1.5 M cesium iodide and 1.0 M bismuth iodide were dissolved in this (solution 1). In the following description, solutions 1 to 8 are transparent conductive film precursors.
The solution 1 was dropped on a quartz glass plate in the atmosphere, spin-coated at 3000 rpm for 30 seconds (slope time: 5 seconds), and heated at 100 ° C. for 30 minutes. The deposited transparent conductive film was Cs ₃ Bi ₂ I ₉ .
<Example 2>
Instead of the solution 1, a solution (solution 2) in which 1.5 M methylamine / hydrogen iodide salt and 1.0 M bismuth iodide are dissolved in DMSO is used, and the heating temperature after spin coating is changed from 100 ° C. to 70 ° C. A transparent conductive film was produced and evaluated in the same manner as in Example 1 except that the temperature was changed to ° C. The deposited transparent conductive film was methylammonium bismuth iodide: (CH ₃ NH ₃ ) ₃ Bi ₂ I ₉ .

<Example 3>
Transparent conductive film as in Example 1 except that DMSO was used instead of Solution 1 and a solution (Solution 3) in which 1.5 M cesium bromide and 1.0 M bismuth bromide were dissolved was used. Were prepared and evaluated. The deposited transparent conductive film was Cs ₃ Bi ₂ Br ₉ .

<Example 4>
Instead of the solution 1, a solvent in which DMSO and HCl were mixed at a volume ratio of 10: 1 was used, and a solution (solution 4) in which 1.5 M cesium chloride and 1.0 M bismuth chloride were dissolved was used. Produced and evaluated a transparent conductive film in the same manner as in Example 1. The deposited transparent conductive film was Cs ₃ Bi ₂ Cl ₉ .

<Example 5>
A transparent conductive film was formed in the same manner as in Example 1 except that a solution (solution 5) obtained by dissolving 1.5M methylamine / hydrogen chloride salt and 1.0M bismuth chloride in DMSO was used instead of the solution 1. Preparation and evaluation. The deposited transparent conductive film was methylammonium bismuth chloride: (CH ₃ NH ₃ ) ₃ Bi ₂ Cl ₉ .

<Example 6>
A transparent conductive film was prepared in the same manner as in Example 1 except that a solution (solution 6) in which 1.5 M dimethylamine / hydrochloride and 1.0 M bismuth chloride were dissolved in DMSO was used instead of the solution 1. Preparation and evaluation. The deposited transparent conductive film was dimethylammonium bismuth chloride: ((CH ₃ ) ₂ NH ₂ ) ₃ Bi ₂ Cl ₉ .

<Comparative Example 1>
A transparent conductive film was formed in the same manner as in Example 1 except that a solution (solution 7) in which 0.2 M tin acetate was dissolved in 2-propanol was used and the heating temperature after spin coating was changed from 100 ° C to 500 ° C. Preparation and evaluation. Deposited transparent conductive film, was SnO _2.

<Example 7>
A transparent conductive film was prepared in the same manner as in Example 1 except that a solution (solution 8) in which 1.5M guanidine / hydrogen chloride salt and 1.0M bismuth chloride were dissolved in DMSO was used instead of solution 1. ,evaluated. The deposited transparent conductive film was guanidine bismuth chloride: (CH ₆ N ₃ ) ₃ Bi ₂ Cl ₉ .

<Example 8>
Instead of Solution 1, a transparent conductive material was obtained in the same manner as in Example 1 except that a solution (solution 9) in which 1.5 M 2-adamantanamine / hydrogen chloride salt and 1.0 M bismuth chloride were dissolved in DMSO was used. Membranes were made and evaluated. The deposited transparent conductive film was 2-adamantan ammonium bismuth chloride: (C ₁₀ H ₁₅ NH ₃ ) ₃ Bi ₂ Cl ₉ .

<Example 9>
A 0.2 mm Teflon (registered trademark; polytetrafluoroethylene) sheet was placed on the transparent conductive film produced in Example 2, and subjected to hot pressing for 30 minutes at 70 ° C. under a pressure of 0.3 MPa. Then, the sample was prepared by removing the Teflon sheet. A change was observed in the transmittance as compared with Example 2. The results are shown in Table 3.

<Example 10>
A 0.2 mm Teflon (registered trademark; polytetrafluoroethylene) sheet was placed on the transparent conductive film produced in Example 2, and subjected to hot pressing for 30 minutes at 70 ° C. under a pressure of 0.8 MPa. Then, the sample was prepared by removing the Teflon sheet. A change was observed in the transmittance as compared with Example 2. The results are shown in Table 3.

<Example 11>
A 0.2 mm Teflon (registered trademark; polytetrafluoroethylene) sheet was placed on the transparent conductive film produced in Example 5 and subjected to hot pressing for 30 minutes at 70 ° C. under a pressure of 0.3 MPa. Then, the sample was prepared by removing the Teflon sheet. A change was observed in the transmittance as compared with Example 5. The results are shown in Table 3.

<Example 12>
A 0.2 mm Teflon (registered trademark; polytetrafluoroethylene) sheet was placed on the transparent conductive film produced in Example 5 and subjected to hot pressing for 30 minutes at 70 ° C. under a pressure of 0.8 MPa. Then, the sample was prepared by removing the Teflon sheet. A change was observed in the transmittance as compared with Example 5. The results are shown in Table 3.

<Example 13>
A transparent conductive film was produced in the same manner as in Example 5 except that the quartz glass plate of Example 5 was changed to a soda glass plate having a thickness of 2 mm. In this case, the film could be formed at a film formation temperature of 70 ° C., and the deposited transparent conductive film was (CH ₃ NH ₃ ) ₃ Bi ₂ Cl ₉ .

<Example 14>
A transparent conductive film was produced in the same manner as in Example 5 except that the quartz glass plate of Example 5 was changed to a plastic plate (PET) having a thickness of 0.5 mm. In this case, the film could be formed at a film forming temperature of 100 ° C., and the deposited transparent conductive film was (CH ₃ NH ₃ ) ₃ Bi ₂ Cl ₉ .

  It was shown that the transparent conductive films in Examples 1 to 9 can be produced at a low temperature of 100 ° C. or lower. Furthermore, in Examples 13 and 14, it is shown that various base materials can be applied. In particular, even in the case of using a plastic substrate in Example 14, a desired transparent conductive film can be manufactured, and the heat resistance of the substrate can be increased. It was shown that the sex constraint is small.

  It was shown that the transparent conductive films of Examples 1 to 8 can be etched by using DMF as a safer solvent than strong acids. This means that the transparent conductive films of Examples 9 to 12 using the transparent conductive films of Examples 2 and 5 can be similarly etched. On the other hand, the transparent conductive film of Comparative Example 1 could not be etched with DMF. That is, it was shown that a transparent conductive film advantageous for patterning can be obtained by satisfying the configuration of the present embodiment.

  In the transparent conductive film of Examples 1-6, it was shown that the effective mass ratio of an electron is small, and it was shown that the transparent conductive film advantageous to an electron movement is obtained by satisfy | filling the structure of this embodiment. .

  From the results of evaluation of the transparent conductive films of Examples 5 to 8, in particular, the result of the change in absorption edge by changing the type of molecular cation, these molecular cations were introduced into the crystal lattice of each main material. It was shown that various molecular cations can be applied as constituent cations of the main material of the transparent conductive film. In particular, it is surprising that the bulky adamantane containing material of Example 8 can be included in the crystal lattice. Each of these examples is found to be excellent in flexibility because it contains an organic molecular cation. In particular, the main material of Example 8 contains adamantane having a polycyclic structure and / or an intramolecular bridge structure. It was shown that the flexibility is remarkably excellent. In addition, a transparent conductive film containing a cation having a large sum of carbon and nitrogen constituting an organic molecular cation, particularly a guanidinium cation or a 2-adamantanammonium cation, has a significantly short absorption edge, which is advantageous for transparency. It was shown to be.

  From the results of Examples 9 to 12, it was shown that the transparent conductive film of the present embodiment can be advantageous in transparency by increasing the transmittance by applying a pressing process under appropriate conditions.

Claims (40)

Including cations and anions,
20 mol% or more and 90 mol% or less of the cation is a cation of a group 13-15 element,
A transparent conductive film, wherein 40 mol% or more and 100 mol% or less of the anion is an anion of a Group 17 element.   The transparent conductive film according to claim 1, wherein 25 mol% or more and 80 mol% or less of the cation is a cation of a group 13 to 15 element.   The transparent conductive film according to claim 1, wherein the cation of the Group 13 to 15 element includes a cation of an element selected from the group consisting of Group 15 elements.   The transparent conductive film according to any one of claims 1 to 3, wherein the cation of the Group 13 to 15 element is a bismuth cation. The cations of the 13 to 15 group elements comprises a cation having an electronic arrangement comprising a s ² d ¹⁰ p ^0, a transparent conductive film according to any one of claims 1 to 4.   The transparent conductive film according to any one of claims 1 to 5, wherein 60 mol% or more of the anions are group 17 element anions.   The transparent conductive film according to any one of claims 1 to 6, wherein the Group 17 element is any one selected from the group consisting of Cl, Br and I.   The transparent conductive film according to claim 1, wherein 60 mol% or more and 100 mol% or less of the anion is a chlorine anion.   The transparent conductive film according to any one of claims 1 to 8, wherein a counter cation of the cation of the Group 13 to 15 element is 10 mol% or more and 80 mol% or less of the cation.   The transparent conductive film according to claim 9, wherein the counter cation includes a single element cation.   The transparent conductive film according to claim 10, wherein the single element cation includes a cation of an element selected from the group consisting of Group 1 elements to Group 3 elements.   The transparent conductive film according to claim 10 or 11, wherein the single element cation contains an element selected from the group consisting of Cs, Rb, K, and Na. The main material of the transparent conductive film, a Cs ₃ Bi ₂ X _9, wherein said X is I, Br or Cl, a transparent conductive film according to any one of claims 10 to 12.   The transparent conductive film according to claim 9, wherein the counter cation includes a molecular cation.   The transparent conductive film according to claim 14, wherein the molecular cation is an organic molecular cation.   The transparent conductive film according to claim 15, wherein the organic molecular cation has 1 to 20 carbon atoms.   The transparent conductive film according to claim 14, wherein the molecular cation contains an ammonium group.   The transparent conductive film according to claim 15, wherein the organic molecular cation contains a methyl group.   The transparent conductive film according to claim 15, wherein the molecular cation includes a methylammonium cation. The transparent conductive film according to claim 19, wherein a main material of the transparent conductive film is (CH ₃ NH ₃ ) ₃ Bi ₂ X ₉ , wherein X is I, Br or Cl.   The transparent conductive film according to claim 15, wherein the molecular cation includes a dimethylammonium cation. The transparent conductive film according to claim 21, wherein a main material of the transparent conductive film is ((CH ₃ ) ₂ NH ₂ ) ₃ Bi ₂ X ₉ , where X is I, Br or Cl.   The transparent conductive film according to claim 15, wherein the molecular cation includes a guanidinium cation. The transparent conductive film according to claim 23, wherein a main material of the transparent conductive film is (CH ₆ N ₃ ) ₃ Bi ₂ X ₉ , where X is I, Br or Cl.   The transparent conductive film according to claim 15, wherein the organic molecular cation includes a cyclic carbon chain.   The transparent conductive film according to claim 25, wherein the cyclic carbon chain includes a polycyclic structure.   The transparent conductive film according to claim 25, wherein the cyclic carbon chain includes an intramolecular crosslinked structure.   The transparent conductive film according to claim 27, wherein the crosslinked structure of the intramolecular crosslinked structure contains methylene.   The transparent conductive film according to any one of claims 25 to 28, wherein the cyclic carbon chain is adamantane. The main material of the transparent conductive film is a _{(C 10 H 15 NH 3)} 3 Bi 2 X 9, wherein said X is I, Br or Cl, in any one of claims 25 to 29 The transparent conductive film as described.   The transparent conductive film according to any one of claims 1 to 30, comprising a structure in which the anion is coordinated to a cation of the group 13 to 15 element.   The transparent conductive film according to any one of claims 1 to 31, which has a structure in which at least a part of the anion is coordinated with a plurality of the Group 13 to 15 elements.   The transparent conductive film according to any one of claims 1 to 32, comprising a structure in which the Group 13 to 15 element is six-coordinated to the anion.   The transparent conductive film according to any one of claims 1 to 33, wherein the film thickness is 1 nm or more and 10 cm or less.   The transparent conductive film of any one of Claims 1-34 which is contacting the base material.   The transparent conductive film according to claim 35, wherein the substrate comprises glass.   36. The transparent conductive film according to claim 35, wherein the substrate comprises plastic. A method for producing the transparent conductive film according to claim 1,
A step of dissolving a substance containing a cation and an anion in an aprotic organic solvent to obtain a solution, a step of removing the solvent from the solution to obtain a transparent conductive film precursor, and the transparent conductive film precursor, And maintaining the temperature at 0 ° C. or higher and 400 ° C. or lower to obtain the transparent conductive film.   The manufacturing method of the transparent conductive film of any one of Claims 1-37 including the process of applying the pressure of 0.1 Mpa or more and 100 Mpa or less to the said transparent conductive film after the process of obtaining the said transparent conductive film.   40. The method for producing a transparent conductive film according to claim 39, wherein the temperature in the step of applying the pressure is 0 ° C. or higher and 200 ° C. or lower.