Thermoelectric conversion element and its manufacturing method

Abstract

To provide a thermoelectric conversion element having a thermoelectric element layer excellent in shape controllability and capable of being highly integrated, and a method of manufacturing the thermoelectric conversion element.SOLUTION: The thermoelectric conversion element is provided that includes: a substrate having an electrode; a pattern layer having a plurality of spaced openings; and P-type thermoelectric element layers and N-type thermoelectric element layers, each present in the spaced openings, wherein the pattern layer includes a resin, each of the P-type thermoelectric element layers and the N-type thermoelectric element layers is made of a thermoelectric semiconductor composition including a thermoelectric semiconductor material. The method of manufacturing the thermoelectric conversion element is also provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a thermoelectric conversion element and a method for manufacturing the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, as one of the means for effectively utilizing energy, there has been a device that directly converts thermal energy into electrical energy and vice versa using a thermoelectric conversion module having a thermoelectric effect such as the Seebeck effect or the Peltier effect. Among these, the use of so-called π-type thermoelectric conversion elements is known as the thermoelectric conversion element. The π-type is usually configured by providing a pair of electrodes spaced apart from each other on a substrate, for example, by providing a P-type thermoelectric element on one electrode and an N-type thermoelectric element on the other electrode, also spaced apart from each other, and connecting the upper surfaces of both thermoelectric elements to the electrodes of the opposing substrate.

[0003] In recent years, there has been a demand for improved thermoelectric performance, including improved flexibility, thinning, and high integration of thermoelectric conversion elements. In Patent Document 1, a resin substrate such as polyimide is used as a substrate for a thermoelectric conversion element from the viewpoint of heat resistance and flexibility. In addition, a method is disclosed in which a low-viscosity liquid or paste-like thermoelectric semiconductor composition is used as a thermoelectric element layer, including the viewpoint of thinning by thinning, and a pattern of the thermoelectric element layer is directly formed by a screen printing method or the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 104615 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as in Patent Document 1, in the method of forming a thermoelectric element directly on an electrode as a pattern layer by screen printing or the like using a low-viscosity thermoelectric semiconductor composition made of a thermoelectric semiconductor material, a heat-resistant resin, etc., the shape controllability of the obtained thermoelectric element layer is insufficient, and bleeding occurs at the end of the thermoelectric element layer at the electrode interface, and the shape of the thermoelectric element layer is distorted, etc., and it is not possible to control it to a desired shape. For example, when forming the above-mentioned π-type thermoelectric conversion element, sufficient electrical and physical bonding may not be obtained between the upper surface of the obtained thermoelectric element layer and the electrode surface on the opposing substrate. In this case, the inherent thermoelectric performance of the thermoelectric element layer cannot be fully brought out, such as an increase in thermal resistance, and it is necessary to increase the number of pairs of P-type thermoelectric element layer-N-type thermoelectric element layer in order to obtain a predetermined power generation performance or cooling performance. Furthermore, when highly integrating thermoelectric conversion elements, the variation in resistance value of each of the multiple P-type thermoelectric element layer-N-type thermoelectric element layer pairs may increase, or adjacent thermoelectric element layers may come into contact with each other.

[0006] In view of the above, an object of the present invention is to provide a thermoelectric conversion element having a thermoelectric element layer with excellent shape controllability and capable of being highly integrated, and a method for manufacturing the same. [Means for solving the problem]

[0007] As a result of extensive research into solving the above problems, the inventors have discovered a thermoelectric conversion element having a thermoelectric element layer with excellent shape controllability and capable of being highly integrated by configuring a pattern layer having a plurality of spaced openings on an electrode of a substrate, the pattern layer being a layer containing resin, and the openings being provided with a P-type thermoelectric element layer and an N-type thermoelectric element layer made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material, and have completed the present invention. That is, the present invention provides the following (1) to (8). (1) A thermoelectric conversion element including a substrate having electrodes, a pattern layer having a plurality of spaced openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer present in the spaced openings, wherein the pattern layer is a layer containing a resin, and the P-type thermoelectric element layer and the N-type thermoelectric element layer are made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material. (2) The thermoelectric conversion element according to (1) above, wherein the resin constituting the pattern layer is a polyimide resin, a polyamide resin, a polyetherimide resin, a polyaramid film, or a polyamideimide resin. (3) The thermoelectric conversion element according to (1) above, wherein the substrate is a polyimide film, a polyamide film, a polyetherimide film, a polyaramid film, or a polyamideimide film. (4) The thermoelectric conversion element according to any one of (1) to (3) above, wherein the thermoelectric semiconductor material is a bismuth-tellurium-based thermoelectric semiconductor material, a telluride-based thermoelectric semiconductor material, an antimony-tellurium-based thermoelectric semiconductor material, or a bismuth selenide-based thermoelectric semiconductor material. (5) The thermoelectric conversion element according to any one of the above (1) to (4), wherein the thermoelectric semiconductor composition further contains a heat-resistant resin, and an ionic liquid and / or an inorganic ionic compound. (6) The thermoelectric conversion element according to (5) above, wherein the heat-resistant resin is a polyimide resin, a polyamide resin, a polyamideimide resin, or an epoxy resin. (7) The thermoelectric conversion element according to (1) above, wherein the opening has one or more shapes selected from the group consisting of an irregular shape, a polyhedron, a truncated cone, an elliptical truncated cone, a cylindrical shape, and an elliptical cylindrical shape. (8) A method for producing a thermoelectric conversion element including a substrate having electrodes, a pattern layer having a plurality of spaced-apart openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer in the spaced-apart openings, the pattern layer being a layer containing resin, and the P-type thermoelectric element layer and the N-type thermoelectric element layer being made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material, the method comprising the steps of: forming a pattern layer having spaced-apart openings on the electrodes; filling the spaced-apart openings with a thermoelectric semiconductor composition containing a P-type thermoelectric semiconductor material and a thermoelectric semiconductor composition containing an N-type thermoelectric semiconductor material, respectively; drying the thermoelectric semiconductor composition containing the P-type thermoelectric semiconductor material and the thermoelectric semiconductor composition containing the N-type thermoelectric semiconductor material filled in the spaced-apart openings to obtain a P-type thermoelectric element layer and an N-type thermoelectric element layer; and annealing the obtained P-type thermoelectric element layer and N-type thermoelectric element layer. Effect of the Invention

[0008] According to the present invention, it is possible to provide a thermoelectric conversion element having a thermoelectric element layer with excellent shape controllability and capable of being highly integrated, and a method for manufacturing the same. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view illustrating an example of a thermoelectric conversion element (π-type thermoelectric conversion element) of the present invention. [Diagram 2] FIG. 2 is a plan view for explaining an example of a pattern layer constituting a thermoelectric conversion element of the present invention. [Diagram 3] 1A to 1C are explanatory views showing an example of steps according to a method for producing a thermoelectric conversion element of the present invention in the order of steps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Thermoelectric conversion element] The thermoelectric conversion element of the present invention is a thermoelectric conversion element including a substrate having electrodes, a pattern layer having a plurality of spaced openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer present in the spaced openings, characterized in that the pattern layer is a layer containing a resin, and the P-type thermoelectric element layer and the N-type thermoelectric element layer are made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material. The thermoelectric conversion element of the present invention includes a P-type thermoelectric element layer and an N-type thermoelectric element layer at the openings of the pattern layer made of a resin-containing layer, and the shapes of both the P-type thermoelectric element layer and the N-type thermoelectric element layer are directly reflected by the shape of the openings of the pattern layer, so that the shape controllability of both the obtained thermoelectric element layers is excellent. Therefore, the bonding with the electrode surface constituting the thermoelectric conversion element is improved, the deterioration of the thermoelectric performance due to the increase in thermal resistance is suppressed, and the thermoelectric performance inherent to the thermoelectric element layer is expressed. As a result, the number of thermoelectric element layers required to obtain a predetermined thermoelectric performance can be reduced, leading to a reduction in manufacturing costs. At the same time, this leads to lower power consumption in cooling and higher output in power generation. Furthermore, when π-type thermoelectric conversion elements are integrated, the variation in the resistance value of each of the multiple P-type thermoelectric element layer-N-type thermoelectric element layer pairs is reduced, and adjacent thermoelectric element layers do not come into contact with each other, so that high integration is possible. In this specification, the "openings" are provided at intervals in an area inside the entire area of ​​the pattern layer, as described later, and the planar shape of each opening (when the pattern layer on the electrode of the substrate is viewed from the top) extends in the thickness (depth) direction of the pattern layer to the electrode surface. For example, when the planar shape of an opening is rectangular, the shape of the opening is usually approximately rectangular, although this can be adjusted by the method of forming or processing the pattern layer. Similarly, when the planar shape of an opening is circular, the shape of the opening is usually approximately cylindrical.

[0011] 1 is a cross-sectional view illustrating an example of a thermoelectric conversion element (π-type thermoelectric conversion element) of the present invention. The thermoelectric conversion element 1 has an N-type thermoelectric element layer 6a and a P-type thermoelectric element layer 6b provided in an opening 5 of an opening 5s of a pattern layer 4 made of a layer containing a resin on an electrode 3a of a substrate 2a, and further has a counter electrode substrate having an electrode 3b on the substrate 2b on the upper surface of the N-type thermoelectric element layer 6a and the P-type thermoelectric element layer 6b.

[0012] <Pattern layer> The thermoelectric conversion element of the present invention includes a pattern layer on an electrode of a substrate, the pattern layer including a resin and having predetermined spaced apart openings.

[0013] 2 is a plan view for explaining an example of a pattern layer constituting a thermoelectric conversion element of the present invention (electrode portion and cross-sectional view are not shown). The pattern layer 4 includes openings 5 ​​having openings 5s spaced apart from each other by a predetermined distance and made of a layer containing a resin. The arrangement, number and dimensions of the openings and apertures contained in the pattern layer, including the distance between the openings, are not particularly limited and are appropriately adjusted according to the shape and arrangement of the thermoelectric element layer. The shape of the opening is not particularly limited, and a desired shape can be used. Preferably, the opening is one or more shapes selected from the group consisting of an indefinite shape, a polyhedron, a circular truncated cone, an elliptical truncated cone, a cylindrical shape, and an elliptical cylindrical shape. Examples of the polyhedron include a cube, a rectangular parallelepiped, and a pyramid truncated shape. Since they are easy to form or process, a cube, a rectangular parallelepiped, a pyramid truncated shape, and a cylindrical shape are more preferable. Among these, a rectangular parallelepiped shape and a cube shape are more preferable from the viewpoints of the electrode shape, the shape of the thermoelectric element layer, and the thermoelectric performance. In FIG. 2, the opening 5s is square, and the opening 5 is substantially cubic (not shown), with a total of 4×4 openings and openings.

[0014] Examples of the resin contained in the pattern layer include polyphenylene ether resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyimide resin, polyamide resin, polyetherimide resin, polyaramid film, epoxy resin, and polyamideimide resin. Among these, from the viewpoints of heat resistance (particularly shape stability) and processability, polyimide resins, polyamide resins, polyetherimide resins, polyaramid films, and polyamideimide resins are preferred, and polyimide resins and polyamide resins are more preferred.

[0015] In addition, from the viewpoint of easy formation of the pattern layer, a photosensitive resin composition containing the above-mentioned resin as a main component can be used. By using the photosensitive resin composition, a pattern layer having spaced openings can be obtained by a simple process described later. Examples of commercially available photosensitive resin compositions include photosensitive polyimide (manufactured by Asahi Kasei Corporation, AM-270; alkali-developable positive type), and photosensitive polyimide (manufactured by Asahi Kasei Corporation, I-8100; solvent-developable negative type).

[0016] The pattern layer may contain other components such as colorants, flame retardants, plasticizers, lubricants, fillers, UV absorbers, weather stabilizers, rust inhibitors, antifoaming agents, and wettability adjusters.

[0017] The thickness of the pattern layer is appropriately adjusted depending on the thickness of the thermoelectric element layer, and is preferably 100 nm to 1000 μm, more preferably 1 to 600 μm, further preferably 10 to 400 μm, and particularly preferably 10 to 300 μm.

[0018] As a method for forming the pattern layer, when a photosensitive resin composition is used as the resin, a known method mainly based on photolithography can be used. Specifically, a positive or negative photosensitive resin composition is applied onto an electrode of a substrate, a photomask having a pattern of a predetermined opening is prepared, and a pattern layer of the photosensitive resin is formed by exposure and development. In the case of a positive type, the exposed portion is developed, for example, with an alkali or the like, and dissolved and removed. In the case of a negative type, the unexposed portion is developed, for example, with a solvent or the like, and dissolved and removed. As described above, a method of processing a pattern layer on an electrode of a substrate can be mentioned. In the case of a positive type, the exposed portion dissolves, so that the cross-sectional shape after development has a curved surface, and the inclination angle of the side surface with respect to the electrode surface of the substrate becomes continuously smaller as it moves away from the electrode surface of the substrate. In the case of a negative type, the unexposed portion dissolves during development, contrary to the positive type, so that the cross-sectional shape after development is rectangular or close to a trapezoid can be obtained. The selection of these positive and negative types can be selected according to the desired shape of the opening. In addition, even when a resin composition that does not have photosensitivity is used as the resin, a known method mainly based on photolithography can be used. Specifically, the resin is applied onto the electrode of the substrate, and then a photoresist or the like is applied, a photomask having a predetermined opening pattern is prepared, and a pattern is formed with the photoresist by exposure and development, and then the resin is dissolved or removed by wet etching or dry etching using oxygen plasma, reactive ions, or the like, and then the remaining photoresist is peeled off to process a pattern layer on the electrode of the substrate. Examples of the method for forming the resin include various coating methods such as dip coating, spin coating, spray coating, gravure coating, die coating, and doctor blade coating on the electrode of the substrate.

[0019] Another method for forming a pattern layer having openings is to pattern a layer containing a resin by laser processing. Specifically, a layer containing the resin is applied onto an electrode of a substrate, and the resulting layer containing the resin is irradiated with a laser to directly form a predetermined pattern. The laser for forming the pattern can be a solid-state laser, a gas laser, a semiconductor laser, or the like. A solid-state laser with high output and low running costs can be preferably used. As the solid-state laser, a laser made of YAG or YVO4 crystal can be preferably used, and a laser of 354 nm light, which is the third harmonic of a laser made of Nd-doped YAG crystal, or a laser of 355 nm light, which is the third harmonic of a laser made of Nd-doped YVO4 crystal, is preferably used. The laser can be either continuous or pulsed, but when the layer containing the resin is heated, the layer containing the resin may be decomposed or carbonized poorly due to thermal damage. In order to prevent thermal damage to the layer containing the resin, a pulsed laser is preferred. The shorter the pulse width, the less thermal damage the layer containing the resin is likely to suffer, and a laser with a pulse width of nanoseconds to picoseconds is preferred.

[0020] (substrate) In the thermoelectric conversion element of the present invention, a resin film that does not affect the decrease in electrical conductivity or the increase in thermal conductivity of the thermoelectric element layer is used as the substrate. Among them, polyimide film, polyamide film, polyetherimide film, polyaramid film, or polyamideimide film is preferred because it has excellent flexibility, and even when the thermoelectric element layer (thin film) made of a thermoelectric semiconductor composition is annealed, the substrate does not thermally deform, and the performance of the thermoelectric element layer can be maintained, and it has high heat resistance and dimensional stability. Furthermore, polyimide film is particularly preferred because it is highly versatile.

[0021] From the viewpoints of flexibility, heat resistance, and dimensional stability, the thickness of the resin film is preferably from 1 to 1000 μm, more preferably from 5 to 500 μm, and even more preferably from 10 to 100 μm. The resin film preferably has a 5% weight loss temperature of 300°C or higher, more preferably 400°C or higher, as measured by thermogravimetric analysis. The thermal dimensional change rate measured at 200°C in accordance with JIS K7133 (1999) is preferably 0.5% or lower, more preferably 0.3% or lower. The linear expansion coefficient in the planar direction measured in accordance with JIS K7197 (2012) is 0.1 ppm·°C or higher. -1 ~50ppm·℃ -1 and 0.1 ppm·℃ -1 ~30ppm·℃ -1 It is more preferable that:

[0022] (electrode) Examples of metal materials for the electrodes of the thermoelectric conversion element used in the present invention include copper, gold, nickel, aluminum, rhodium, platinum, chromium, palladium, stainless steel, molybdenum, and alloys containing any of these metals. The thickness of the electrode layer is preferably 10 nm to 200 μm, more preferably 30 nm to 150 μm, and further preferably 50 nm to 120 μm. When the thickness of the electrode layer is within the above range, the electrical conductivity is high and the resistance is low, and sufficient strength as an electrode is obtained.

[0023] The electrodes are formed using the above-mentioned metal materials. Examples of the method for forming the electrodes include a method in which an electrode without a pattern is provided on a resin film, and then processed into a predetermined pattern shape by known physical or chemical treatments, mainly photolithography, or a combination of these, or a method in which an electrode pattern is directly formed by screen printing, inkjet printing, or the like. Methods for forming an electrode without a pattern include dry processes such as PVD (physical vapor deposition) methods such as vacuum deposition, sputtering, and ion plating, or CVD (chemical vapor deposition) methods such as thermal CVD and atomic layer deposition (ALD), or wet processes such as various coating methods and electrodeposition methods such as dip coating, spin coating, spray coating, gravure coating, die coating, and doctor blade methods, silver halide plating, electrolytic plating, electroless plating, and lamination of metal foils, and are appropriately selected depending on the material of the electrode. The electrodes used in the present invention are required to have high electrical conductivity and high thermal conductivity in order to maintain thermoelectric performance, so it is preferable to use electrodes formed by plating or vacuum film formation. Vacuum film formation methods such as vacuum deposition and sputtering, as well as electrolytic plating and electroless plating are preferred because they can easily achieve high electrical conductivity and high thermal conductivity. Depending on the size and dimensional accuracy requirements of the formed pattern, a pattern can also be easily formed through a hard mask such as a metal mask.

[0024] <Thermoelectric element layer> The thermoelectric element layer (hereinafter sometimes referred to as "thin film of thermoelectric element layer") constituting the thermoelectric conversion element of the present invention, i.e., the P-type thermoelectric element layer and the N-type thermoelectric element layer, are made of thermoelectric semiconductor compositions containing a P-type thermoelectric semiconductor material and an N-type thermoelectric semiconductor material, respectively, in that order. Preferably, they are made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material (hereinafter sometimes referred to as "thermoelectric semiconductor fine particles"), a heat-resistant resin, and an ionic liquid and / or an inorganic ionic compound.

[0025] (Thermoelectric semiconductor materials) The thermoelectric semiconductor material used in the present invention, i.e., the thermoelectric semiconductor material contained in the P-type thermoelectric element layer and the N-type thermoelectric element layer, is not particularly limited as long as it is a material that can generate a thermoelectromotive force by applying a temperature difference. For example, bismuth-tellurium-based thermoelectric semiconductor materials such as P-type bismuth telluride and N-type bismuth telluride; telluride-based thermoelectric semiconductor materials such as GeTe and PbTe; antimony-tellurium-based thermoelectric semiconductor materials; ZnSb, Zn3Sb 2、Zn-antimony-based thermoelectric semiconductor materials such as Zn4Sb3; silicon-germanium-based thermoelectric semiconductor materials such as SiGe; bismuth selenide-based thermoelectric semiconductor materials such as Bi2Se3; β-FeSi2, CrSi2, MnSi 1.73 , silicide-based thermoelectric semiconductor materials such as Mg2Si; oxide-based thermoelectric semiconductor materials; Heusler materials such as FeVAl, FeVAlSi, FeVTiAl, sulfide-based thermoelectric semiconductor materials such as TiS2, etc. are used. Among these, bismuth-telluride-based thermoelectric semiconductor materials, telluride-based thermoelectric semiconductor materials, antimony-telluride-based thermoelectric semiconductor materials, or bismuth selenide-based thermoelectric semiconductor materials are preferred.

[0026] Furthermore, from the viewpoint of thermoelectric performance, it is more preferable to be a bismuth-telluride-based thermoelectric semiconductor material such as P-type bismuth telluride or N-type bismuth telluride. The P-type bismuth telluride has holes as carriers and a positive Seebeck coefficient. For example, Bi X Te3Sb 2-X represented by is preferably used. In this case, X is preferably 0 < X ≤ 0.8, more preferably 0.4 ≤ X ≤ 0.6. When X is greater than 0 and less than or equal to 0.8, the Seebeck coefficient and electrical conductivity increase, and the characteristics as a P-type thermoelectric element are maintained, which is preferable. Also, the N-type bismuth telluride has electrons as carriers and a negative Seebeck coefficient. For example, Bi2Te 3-Y Se Y represented by is preferably used. In this case, Y is preferably 0 ≤ Y ≤ 3 (when Y = 0: Bi2Te3), more preferably 0 < Y ≤ 2.7. When Y is 0 or more and 3 or less, the Seebeck coefficient and electrical conductivity increase, and the characteristics as an N-type thermoelectric element are maintained, which is preferable.

[0027] The thermoelectric semiconductor fine particles used in the thermoelectric semiconductor composition are those obtained by pulverizing the above-mentioned thermoelectric semiconductor materials to a predetermined size using a pulverizing device or the like.

[0028] The amount of thermoelectric semiconductor particles in the thermoelectric semiconductor composition is preferably 30 to 99% by mass, more preferably 50 to 96% by mass, and even more preferably 70 to 95% by mass. When the amount of thermoelectric semiconductor particles is within the above range, the Seebeck coefficient (absolute value of Peltier coefficient) is large, and the decrease in electrical conductivity is suppressed, and only the thermal conductivity decreases, so that a film exhibiting high thermoelectric performance and having sufficient film strength and flexibility can be obtained, which is preferable.

[0029] The average particle size of the thermoelectric semiconductor particles is preferably 10 nm to 200 μm, more preferably 10 nm to 30 μm, further preferably 50 nm to 10 μm, and particularly preferably 1 to 6 μm. Within the above range, uniform dispersion is facilitated and electrical conductivity can be increased. The method for pulverizing the thermoelectric semiconductor material to obtain thermoelectric semiconductor fine particles is not particularly limited, and the material may be pulverized to a predetermined size using a known fine pulverizing device such as a jet mill, ball mill, bead mill, colloid mill, or roller mill. The average particle size of the thermoelectric semiconductor particles was obtained by measurement using a laser diffraction particle size analyzer (Malvern, Mastersizer 3000) and was taken as the median value of the particle size distribution.

[0030] In addition, the thermoelectric semiconductor fine particles are preferably heat-treated in advance (the "heat treatment" here is different from the "annealing treatment" performed in the annealing treatment step in the present invention). By performing the heat treatment, the crystallinity of the thermoelectric semiconductor fine particles is improved, and further, the surface oxide film of the thermoelectric semiconductor fine particles is removed, so that the Seebeck coefficient or Peltier coefficient of the thermoelectric conversion material is increased, and the thermoelectric figure of merit can be further improved. The heat treatment is not particularly limited, but is preferably performed in an inert gas atmosphere such as nitrogen or argon, in a reducing gas atmosphere such as hydrogen, or under vacuum conditions with a controlled gas flow rate, before preparing the thermoelectric semiconductor composition, so as not to adversely affect the thermoelectric semiconductor fine particles, and more preferably in a mixed gas atmosphere of an inert gas and a reducing gas. The specific temperature conditions depend on the thermoelectric semiconductor fine particles used, but it is usually preferable to perform the heat treatment at a temperature below the melting point of the fine particles and at 100 to 1500°C for several minutes to several tens of hours.

[0031] (Heat-resistant resin) A heat-resistant resin is preferably used for the thermoelectric semiconductor composition used in the present invention, from the viewpoint of annealing the thermoelectric semiconductor material at a high temperature after forming the thermoelectric element layer. It acts as a binder between the thermoelectric semiconductor material (thermoelectric semiconductor fine particles), and can increase the flexibility of the thermoelectric conversion module, and also makes it easier to form a thin film by coating or the like. The heat-resistant resin is not particularly limited, but is preferably a heat-resistant resin that maintains various physical properties such as mechanical strength and thermal conductivity as a resin without being impaired when a thin film made of the thermoelectric semiconductor composition is annealed or the like to cause crystal growth of the thermoelectric semiconductor fine particles. The heat-resistant resin is preferably a polyamide resin, a polyamideimide resin, a polyimide resin, or an epoxy resin, because it has higher heat resistance and does not adversely affect the crystal growth of the thermoelectric semiconductor particles in the thin film, and more preferably a polyamide resin, a polyamideimide resin, or a polyimide resin, because it has excellent flexibility. When a polyimide film is used as the substrate of the thermoelectric conversion element, a polyimide resin is more preferable as the heat-resistant resin, because of adhesion to the polyimide film. In the present invention, the polyimide resin is a general term for polyimide and its precursor.

[0032] The heat-resistant resin preferably has a decomposition temperature of 300° C. or higher. If the decomposition temperature is within the above range, the resin can maintain its flexibility without losing its function as a binder, even when a thin film made of the thermoelectric semiconductor composition is annealed, as described below.

[0033] The heat-resistant resin preferably has a mass loss rate of 10% or less, more preferably 5% or less, and even more preferably 1% or less at 300° C. as measured by thermogravimetry (TG). If the mass loss rate is within the above range, the thermoelectric element layer can maintain its flexibility without losing its function as a binder, even when a thin film made of the thermoelectric semiconductor composition is annealed, as described below.

[0034] The amount of the heat-resistant resin in the thermoelectric semiconductor composition is 0.1 to 40% by mass, preferably 0.5 to 20% by mass, more preferably 1 to 20% by mass, and further preferably 2 to 15% by mass. When the amount of the heat-resistant resin is within the above range, the resin functions as a binder for the thermoelectric semiconductor material, making it easier to form a thin film, and a film having both high thermoelectric performance and film strength can be obtained.

[0035] (Ionic Liquid) The ionic liquid used in the present invention is a molten salt formed by combining a cation and an anion, and refers to a salt that can exist in a liquid state in any temperature range of -50 to 500°C. Ionic liquids have characteristics such as extremely low vapor pressure and non-volatility, excellent thermal stability and electrochemical stability, low viscosity, and high ionic conductivity, and therefore can effectively suppress the reduction in electrical conductivity between thermoelectric semiconductor particles as a conductive auxiliary. In addition, ionic liquids exhibit high polarity based on an aprotic ionic structure and have excellent compatibility with heat-resistant resins, so that the electrical conductivity of the thermoelectric element layer can be made uniform.

[0036] The ionic liquid may be a known or commercially available one. For example, a mixture of a cationic component such as a pyridinium, pyrimidinium, pyrazolium, pyrrolidinium, piperidinium, imidazolium, etc., a nitrogen-containing cyclic cationic compound and a derivative thereof; an amine-based cation of tetraalkylammonium and a derivative thereof; a phosphine-based cation such as phosphonium, trialkylsulfonium, tetraalkylphosphonium, etc. and a derivative thereof; a lithium cation and a derivative thereof; and a mixture of a Cl - , AlCl4 - , Al2Cl7 - , ClO4 - Chloride ions such as Br - bromide ions, such as I - Iodide ions such as BF4 - , PF6 - Fluoride ions such as F(HF) n - Halide anions such as NO3 - , CH3COO - , CF3COO - , CH3SO3 - , CF3SO3 - , (FSO2)2N - , (CF3SO2)2N - , (CF3SO2)3C - , AsF6 - , SbF6 - , NbF6 - , TaF6 - , F(HF)n - , (CN)2N - , C4F9SO3 - , (C2F5SO2)2N - , C3F7COO - , (CF3SO2)(CF3CO)N - and an anion component such as the above.

[0037] Among the above ionic liquids, from the viewpoints of high temperature stability, compatibility with thermoelectric semiconductor particles and resins, and suppression of a decrease in the electrical conductivity of the gaps between thermoelectric semiconductor particles, it is preferable that the cationic component of the ionic liquid contains at least one selected from pyridinium cations and derivatives thereof, and imidazolium cations and derivatives thereof. It is preferable that the anionic component of the ionic liquid contains a halide anion, and Cl - , Br - and I - It is more preferable that the composition contains at least one selected from the following:

[0038] Specific examples of ionic liquids in which the cationic component contains a pyridinium cation and a derivative thereof include 4-methyl-butylpyridinium chloride, 3-methyl-butylpyridinium chloride, 4-methyl-hexylpyridinium chloride, 3-methyl-hexylpyridinium chloride, 4-methyl-octylpyridinium chloride, 3-methyl-octylpyridinium chloride, 3,4-dimethyl-butylpyridinium chloride, 3,5-dimethyl-butylpyridinium chloride, 4-methyl-butylpyridinium tetrafluoroborate, 4-methyl-butylpyridinium hexafluorophosphate, 1-butyl-4-methylpyridinium bromide, 1-butyl-4-methylpyridinium hexafluorophosphate, and 1-butyl-4-methylpyridinium iodide. Of these, 1-butyl-4-methylpyridinium bromide, 1-butyl-4-methylpyridinium hexafluorophosphate, and 1-butyl-4-methylpyridinium iodide are preferred.

[0039] Specific examples of ionic liquids in which the cationic component contains an imidazolium cation and a derivative thereof include [1-butyl-3-(2-hydroxyethyl)imidazolium bromide], [1-butyl-3-(2-hydroxyethyl)imidazolium tetrafluoroborate], 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, 1-octyl-3-methylimidazolium chloride, 1-decyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride. Examples of the imidazolium bromide include 1-dodecyl-3-methylimidazolium chloride, 1-tetradecyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-hexyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-methyl-3-butylimidazolium methyl sulfate, and 1,3-dibutylimidazolium methyl sulfate. Among these, [1-butyl-3-(2-hydroxyethyl)imidazolium bromide] and [1-butyl-3-(2-hydroxyethyl)imidazolium tetrafluoroborate] are preferred.

[0040] The above ionic liquid has an electrical conductivity of 10 -7 S / cm or more is preferable, and 10 -6 If the electrical conductivity is in the above range, the thermoelectric semiconductor material can effectively suppress the decrease in electrical conductivity between the thermoelectric semiconductor particles as a conductive auxiliary.

[0041] The ionic liquid preferably has a decomposition temperature of 300° C. or higher. If the decomposition temperature is within the above range, the effect as a conductive auxiliary agent can be maintained even when a thin film made of the thermoelectric semiconductor composition is annealed, as described later.

[0042] The ionic liquid preferably has a mass loss rate of 10% or less, more preferably 5% or less, and even more preferably 1% or less at 300° C. as measured by thermogravimetry (TG). If the mass loss rate is within the above range, the ionic liquid can maintain its effect as a conductive auxiliary even when a thin film made of the thermoelectric semiconductor composition is annealed, as described below.

[0043] The amount of the ionic liquid in the thermoelectric semiconductor composition is preferably 0.01 to 50% by mass, more preferably 0.5 to 30% by mass, and further preferably 1.0 to 20% by mass. When the amount of the ionic liquid is within the above range, a decrease in electrical conductivity is effectively suppressed, and a film having high thermoelectric performance is obtained.

[0044] (Inorganic ionic compounds) The inorganic ionic compound used in the present invention is a compound composed of at least a cation and an anion. The inorganic ionic compound is a solid at room temperature, has a melting point at any temperature in the temperature range of 400 to 900°C, and has characteristics such as high ionic conductivity, so that it can suppress the decrease in electrical conductivity between thermoelectric semiconductor particles as a conductive auxiliary.

[0045] As the cation, a metal cation is used. Examples of the metal cation include alkali metal cations, alkaline earth metal cations, typical metal cations and transition metal cations, with alkali metal cations and alkaline earth metal cations being more preferred. Examples of alkali metal cations include Li + , Na + , K + , Rb + , Cs + and Fr + etc. Examples of alkaline earth metal cations include Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ etc.

[0046] The anion may be, for example, F - , Cl - , Br - , I - , O.H. - , C.N. - , NO 3- , NO 2- , ClO - , ClO 2- , ClO 3- , ClO 4- , CrO4 2- , HSO4 - , SCN - , BF4 - , PF6 - etc.

[0047] The inorganic ionic compound may be any known or commercially available inorganic ionic compound. For example, a cationic component such as potassium cation, sodium cation, or lithium cation and a Cl - , AlCl4 - , Al2Cl7 - , ClO4 - Chloride ions such as Br - bromide ions, such as I - Iodide ions such as BF4 - , PF6 - Fluoride ions such as F(HF) n - Halide anions such as NO3 - , O.H. - , C.N. - and an anion component such as the above.

[0048] Among the above inorganic ionic compounds, from the viewpoints of high temperature stability, compatibility with thermoelectric semiconductor particles and resin, and suppression of decrease in electrical conductivity in the gaps between thermoelectric semiconductor particles, it is preferable that the cationic component of the inorganic ionic compound contains at least one selected from potassium, sodium, and lithium. Also, it is preferable that the anionic component of the inorganic ionic compound contains a halide anion, and Cl is preferably 0.01 to 0.01. - , Br - , and I -It is more preferable that the composition contains at least one selected from the following:

[0049] Specific examples of inorganic ionic compounds in which the cationic component contains a potassium cation include KBr, KI, KCl, KF, KOH, K2CO3, etc. Among these, KBr and KI are preferred. Specific examples of inorganic ionic compounds in which the cationic component contains a sodium cation include NaBr, NaI, NaOH, NaF, Na2CO3, etc. Among these, NaBr and NaI are preferred. Specific examples of inorganic ionic compounds in which the cationic component contains a lithium cation include LiF, LiOH, LiNO3, etc. Among these, LiF and LiOH are preferred.

[0050] The above inorganic ionic compounds have an electrical conductivity of 10 -7 S / cm or more is preferable, and 10 -6 If the electrical conductivity is within the above range, the thermoelectric semiconductor material can effectively suppress the decrease in electrical conductivity between the thermoelectric semiconductor particles as a conductive auxiliary.

[0051] The inorganic ionic compound preferably has a decomposition temperature of 400° C. or higher. If the decomposition temperature is within the above range, the effect as a conductive auxiliary agent can be maintained even when a thin film made of the thermoelectric semiconductor composition is annealed, as described later.

[0052] The inorganic ionic compound preferably has a mass loss rate of 10% or less, more preferably 5% or less, and even more preferably 1% or less at 400° C. as measured by thermogravimetry (TG). If the mass loss rate is within the above range, the compound can maintain its effect as a conductive auxiliary even when a thin film of a thermoelectric element layer made of the thermoelectric semiconductor composition is annealed, as described below.

[0053] The amount of the inorganic ionic compound in the thermoelectric semiconductor composition is preferably 0.01 to 50 mass%, more preferably 0.5 to 30 mass%, and further preferably 1.0 to 10 mass%. When the amount of the inorganic ionic compound is within the above range, the decrease in electrical conductivity can be effectively suppressed, and as a result, a film with improved thermoelectric performance can be obtained. In addition, when an inorganic ionic compound and an ionic liquid are used in combination, the total content of the inorganic ionic compound and the ionic liquid in the thermoelectric semiconductor composition is preferably 0.01 to 50 mass%, more preferably 0.5 to 30 mass%, and even more preferably 1.0 to 10 mass%.

[0054] (Other additives) In addition to the components other than those described above, the thermoelectric semiconductor composition used in the present invention may further contain, as necessary, other additives such as dispersants, film-forming assistants, light stabilizers, antioxidants, tackifiers, plasticizers, colorants, resin stabilizers, fillers, pigments, conductive fillers, conductive polymers, curing agents, etc. These additives may be used alone or in combination of two or more.

[0055] (Method for preparing thermoelectric semiconductor composition) The method for preparing the thermoelectric semiconductor composition used in the present invention is not particularly limited, and the thermoelectric semiconductor composition may be prepared by mixing and dispersing the thermoelectric semiconductor fine particles, the heat-resistant resin, and the ionic liquid and / or inorganic ionic compound, as well as the other additives as necessary and a solvent, using a known method such as an ultrasonic homogenizer, a spiral mixer, a planetary mixer, a disperser, or a hybrid mixer. Examples of the solvent include toluene, ethyl acetate, methyl ethyl ketone, alcohol, tetrahydrofuran, methylpyrrolidone, ethyl cellosolve, and the like. These solvents may be used alone or in combination of two or more. The solid content concentration of the thermoelectric semiconductor composition is not particularly limited as long as the composition has a viscosity suitable for coating.

[0056] The thin film of the thermoelectric element layer made of the thermoelectric semiconductor composition can be formed by filling the openings of the pattern layer used in the present invention with the thermoelectric semiconductor composition and drying it. By forming the thermoelectric element layer in this manner, a thermoelectric element layer with excellent shape controllability that reflects the shape of the openings of the pattern layer can be obtained.

[0057] <Annealing treatment> The thermoelectric element layers formed by filling and drying the thermoelectric semiconductor composition, i.e., the P-type thermoelectric element layer and the N-type thermoelectric element layer, can be further annealed to stabilize the thermoelectric performance and cause crystal growth of the thermoelectric semiconductor particles in the thermoelectric element layer, thereby further improving the thermoelectric performance.

[0058] The annealing treatment is not particularly limited, but is usually carried out under an inert gas atmosphere such as nitrogen or argon, under a reducing gas atmosphere, or under vacuum conditions with the gas flow rate controlled, and depends on the heat-resistant resin, ionic liquid, inorganic ionic compound, and the heat resistance temperature of the substrate, the layer containing the resin used as the pattern layer, etc., but the annealing temperature is usually 100 to 600°C for several minutes to several tens of hours, preferably 150 to 550°C for several minutes to several tens of hours, and more preferably 200 to 500°C for several minutes to several tens of hours.

[0059] The thickness of the thin film of the thermoelectric element layer made of the thermoelectric semiconductor composition is not particularly limited, but from the viewpoints of thermoelectric performance and film strength, it is preferably 100 nm to 1000 μm, more preferably 1 to 600 μm, even more preferably 10 to 400 μm, and particularly preferably 10 to 300 μm.

[0060] The thermoelectric conversion element of the present invention is preferably applied to the above-mentioned π-type thermoelectric conversion element from the viewpoint of excellent shape controllability of the thermoelectric element layer and improved bonding with the electrode part. The π-type thermoelectric conversion element is configured, for example, by providing a pair of electrodes spaced apart from each other on a substrate, providing a P-type thermoelectric element layer on one electrode and an N-type thermoelectric element layer on the other electrode, also spaced apart from each other, and electrically connecting the upper surfaces of both thermoelectric element layers in series to electrodes on the opposing substrate. From the viewpoint of efficiently obtaining high thermoelectric performance, it is preferable to use a plurality of pairs of P-type thermoelectric element layers and N-type thermoelectric element layers electrically connected in series via the electrodes of the opposing substrates.

[0061] [Method of manufacturing thermoelectric conversion element] The method for producing a thermoelectric conversion element of the present invention is a method for producing a thermoelectric conversion element including a substrate having electrodes, a pattern layer having a plurality of spaced-apart openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer in the spaced-apart openings, wherein the pattern layer is a layer containing resin, and the P-type thermoelectric element layer and the N-type thermoelectric element layer are made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material, the method comprising the steps of: forming a pattern layer having spaced-apart openings on the electrodes; filling the spaced-apart openings with a thermoelectric semiconductor composition containing a P-type thermoelectric semiconductor material and a thermoelectric semiconductor composition containing an N-type thermoelectric semiconductor material, respectively; drying the thermoelectric semiconductor composition containing the P-type thermoelectric semiconductor material and the thermoelectric semiconductor composition containing the N-type thermoelectric semiconductor material filled in the spaced-apart openings to obtain a P-type thermoelectric element layer and an N-type thermoelectric element layer; and annealing the obtained P-type thermoelectric element layer and N-type thermoelectric element layer. Hereinafter, the method for producing a thermoelectric conversion element of the present invention will be described with reference to the drawings.

[0062] FIG. 3 is an explanatory diagram showing an example of steps according to a method for producing a thermoelectric conversion element of the present invention in the order of steps. 1A is a cross-sectional view of the substrate after electrodes are formed, (b) is a cross-sectional view of the substrate after a resin-containing layer is formed, (c) is a plan view of the pattern layer after openings are formed in the resin-containing layer (electrode portion not shown), (c') is a cross-sectional view of the pattern layer cut along the line A-A' in (c), (d) is a cross-sectional view of the pattern layer after the openings are filled with a thermoelectric element layer, and (e) is a cross-sectional view showing how the upper surface of the thermoelectric element layer obtained in (d) is opposed to and joined to an electrode on a substrate facing the upper surface. This allows a thermoelectric conversion element to be obtained.

[0063] <Pattern layer formation process> The pattern layer forming step is a step of forming a pattern layer made of a layer containing a resin on the electrode of the substrate. For example, in Fig. 3(b), a layer 14' containing a resin is applied onto the electrode 13a of the substrate 12a prepared in (a), to form a pattern layer 14 having the spaced openings 15s and the openings 15 in (c) and (c').

[0064] The method for forming the pattern layer is not particularly limited, but from the viewpoint of pattern accuracy, as described above, when a photosensitive resin composition is used as the layer containing the resin, a known method mainly based on photolithography can be used, and a pattern layer can be easily obtained using a photomask or the like. Similarly, when a resin composition that does not have photosensitivity is used as the layer containing the resin, a known method mainly based on photolithography can be used as described above. Furthermore, as described above, a method of directly patterning the layer containing the resin by laser processing can be used.

[0065] <Thermoelectric element layer formation process> The thermoelectric element layer forming step includes a thermoelectric semiconductor composition filling step and a thermoelectric semiconductor composition drying step.

[0066] (Thermoelectric semiconductor composition filling process) The thermoelectric semiconductor composition filling step is a step of filling the spaced apart openings of the pattern layer obtained in the pattern layer forming step with a thermoelectric semiconductor composition containing a P-type thermoelectric semiconductor material and a thermoelectric semiconductor composition containing an N-type thermoelectric semiconductor material, respectively. For example, in FIG. 3(d), it is a step of filling the opening 15 having an opening 15s of the pattern layer 14 made of the layer 14' containing the resin prepared in (c) and (c') with a thermoelectric semiconductor composition containing a P-type thermoelectric semiconductor material and a thermoelectric semiconductor composition containing an N-type thermoelectric semiconductor material, respectively. Methods for filling the openings in the pattern layer with the thermoelectric semiconductor composition include known methods such as screen printing, flexographic printing, gravure printing, spin coating, die coating, spray coating, bar coating, doctor blade, dispensing, etc. From the viewpoints of filling accuracy and production efficiency, it is preferable to use the screen printing, stencil printing, and dispensing methods.

[0067] (Thermoelectric semiconductor composition drying process) The thermoelectric semiconductor composition drying step is a step of drying the thermoelectric semiconductor composition containing the P-type thermoelectric semiconductor material and the thermoelectric semiconductor composition containing the N-type thermoelectric semiconductor material filled in the spaced apart openings to obtain a P-type thermoelectric element layer and an N-type thermoelectric element layer. For example, in Fig. 3(d), this is a step of drying the thermoelectric semiconductor composition containing the P-type thermoelectric semiconductor material and the thermoelectric semiconductor composition containing the N-type thermoelectric semiconductor material filled in the openings 15 obtained in (c) and (c') to form a P-type thermoelectric element layer 16b and an N-type thermoelectric element layer 16a. As the drying method, as described above, a conventionally known drying method such as hot air drying, hot roll drying, infrared irradiation, etc. can be used. The heating temperature is usually 80 to 150° C., and the heating time varies depending on the heating method, but is usually several seconds to several tens of minutes. When a solvent is used in the preparation of the thermoelectric semiconductor composition, the heating temperature is not particularly limited as long as it is within a temperature range in which the solvent used can be dried.

[0068] Annealing process The present invention includes a step of annealing the P-type thermoelectric element layer and the N-type thermoelectric element layer. The annealing process is a process of heat treating the P-type thermoelectric element layer and the N-type thermoelectric element layer obtained in the thermoelectric semiconductor composition drying process. As described above, the annealing process stabilizes the thermoelectric performance and also allows the thermoelectric semiconductor particles in the thin film of the thermoelectric element layer to grow crystals, thereby further improving the thermoelectric performance. The conditions for the annealing process are as described above.

[0069] (π-type thermoelectric conversion element manufacturing process) The π-type thermoelectric conversion element manufacturing process is a process in which the thermoelectric element layer side of the substrate including the P-type thermoelectric element layer and the N-type thermoelectric element layer obtained in the annealing process is opposed to an electrode on an opposing substrate, and bonded together to form a thermoelectric conversion element. For example, in Fig. 3(e), the upper surface side of the N-type thermoelectric element layer 16a and the P-type thermoelectric element layer 16b is opposed to the electrode 13b on the substrate 12b, and bonded together via a bonding material layer (not shown) or the like. This process allows the manufacture of a π-type thermoelectric conversion element. As the counter substrate and the electrodes, the same substrate and electrodes as those described above can be used. Examples of the bonding material used for the bonding material layer include a solder material, a conductive adhesive, and a sintering bonding agent, and these are preferably formed on the electrodes as a solder layer, a conductive adhesive layer, and a sintering bonding layer, respectively.

[0070] According to the method for producing a thermoelectric conversion element of the present invention, it is possible to improve the shape controllability of the thermoelectric element layer in a simple manner, thereby realizing high integration of thermoelectric conversion elements. [Industrial Applicability]

[0071] According to the thermoelectric conversion element and the manufacturing method thereof of the present invention, a thermoelectric conversion element having a thermoelectric element layer with excellent shape controllability and capable of being highly integrated can be obtained by a simple manufacturing method. At the same time, since the variation in the resistance value of each of the multiple P-type thermoelectric element layer-N-type thermoelectric element layer pairs can be reduced, an improvement in the manufacturing yield can be expected. Furthermore, the thermoelectric conversion element of the present invention has flexibility and can be made thin (compact and lightweight). The above thermoelectric conversion element, when made into a thermoelectric conversion module, can be used for power generation applications in which exhaust heat from various combustion furnaces such as factories, waste combustion furnaces, and cement combustion furnaces, exhaust heat from automobile combustion gases, and exhaust heat from electronic devices are converted into electricity. As cooling applications, in the field of electronic devices, the thermoelectric conversion element can be used for temperature control of various sensors such as CPUs (Central Processing Units) used in smartphones and various computers, image sensors such as CMOS (Complementary Metal Oxide Semiconductor Image Sensors) and CCD (Charge Coupled Devices), and further, MEMS (Micro Electro Mechanical Systems) and other light receiving elements. [Explanation of symbols]

[0072] 1: Thermoelectric conversion element 2a, 2b: Substrate 3a,3b: Electrode 4: Pattern layer 5: Opening 5s: opening 6a: N-type thermoelectric element layer 6b: P-type thermoelectric element layer 12a, 12b: Substrate 13a, 13b: Electrode 14: Pattern layer 14': Resin-containing layer 15: Opening 15s: opening 16a: N-type thermoelectric element layer 16b: P type thermoelectric element layer

Claims

1. A thermoelectric conversion element including a substrate having an electrode, a pattern layer having a plurality of spaced apart openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer present in all of the spaced apart openings, the substrate is a polyimide film, a polyamide film, a polyetherimide film, a polyaramid film, or a polyamideimide film; The pattern layer is a layer containing a resin, the pattern layer has a thickness of 10 to 300 μm, and the P-type thermoelectric element layer and the N-type thermoelectric element layer are made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material.

2. 2. The thermoelectric conversion element according to claim 1, wherein the resin constituting the pattern layer is a polyimide resin, a polyamide resin, a polyetherimide resin, a polyaramid film, or a polyamideimide resin.

3. 3. The thermoelectric conversion element according to claim 1, wherein the thermoelectric semiconductor material is a bismuth-tellurium based thermoelectric semiconductor material, a telluride based thermoelectric semiconductor material, an antimony-tellurium based thermoelectric semiconductor material, or a bismuth selenide based thermoelectric semiconductor material.

4. The thermoelectric conversion element according to any one of claims 1 to 3, wherein the thermoelectric semiconductor composition further contains a heat-resistant resin, and an ionic liquid and / or an inorganic ionic compound.

5. The thermoelectric conversion element according to claim 4 , wherein the heat-resistant resin is a polyimide resin, a polyamide resin, a polyamideimide resin, or an epoxy resin.

6. 2. The thermoelectric conversion element according to claim 1, wherein the opening has one or more shapes selected from the group consisting of an irregular shape, a polyhedral shape, a truncated cone shape, an elliptical truncated cone shape, a cylindrical shape, and an elliptical cylindrical shape.

7. A thermoelectric conversion element including a substrate having an electrode, a pattern layer having a plurality of spaced apart openings, and a P-type thermoelectric element layer and an N-type thermoelectric element layer in all of the spaced apart openings, the substrate is a polyimide film, a polyamide film, a polyetherimide film, a polyaramid film, or a polyamideimide film; A method for producing a thermoelectric conversion element, the pattern layer being a layer containing a resin, the pattern layer having a thickness of 10 to 300 μm, the P-type thermoelectric element layer and the N-type thermoelectric element layer being made of a thermoelectric semiconductor composition containing a thermoelectric semiconductor material, forming a patterned layer having spaced openings over the electrode; filling each of the spaced apart openings with a thermoelectric semiconductor composition including a P-type thermoelectric semiconductor material and a thermoelectric semiconductor composition including an N-type thermoelectric semiconductor material; a step of drying the thermoelectric semiconductor composition containing the P-type thermoelectric semiconductor material and the thermoelectric semiconductor composition containing the N-type thermoelectric semiconductor material filled in the entire spaced apart openings to obtain a P-type thermoelectric element layer and an N-type thermoelectric element layer; and annealing the obtained P-type thermoelectric element layer and N-type thermoelectric element layer; A method for manufacturing a thermoelectric conversion element.

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