Thermoelectric conversion device, method for controlling thermoelectric conversion device, method for cooling and / or heating an object using a thermoelectric conversion device, and electronic device

Abstract

A thermoelectric conversion device equipped with an insulating layer and a thermoelectric conversion module provided on the insulating layer, wherein: the thermoelectric conversion module is provided with a first thermoelectric conversion region and a second thermoelectric conversion region; the first (2) thermoelectric conversion region is provided with one or more thermoelectric conversion elements, a first (3) connecting electrode and a second (4) connecting electrode; the thermoelectric conversion elements of the first (2) thermoelectric conversion region are electrically connected to the first (3) connecting electrode and to the second (4) connecting electrode, and are positioned on an electrical path which connects both connecting electrodes; each of the thermoelectric conversion elements is provided with a thermoelectric conversion unit; the thermoelectric conversion units of the one or more thermoelectric conversion elements are equipped with a phononic crystal layer which has a phononic crystal structure provided with a plurality of regularly arranged through holes; and the pass-through direction of the plurality of through holes in said crystal structure is substantially parallel to a direction perpendicular to the principal surface of the insulating layer.

Description

[Technical field]

[0001] The present disclosure relates to a thermoelectric conversion device, a method for controlling a thermoelectric conversion device, a method for cooling and / or heating an object using a thermoelectric conversion device, and an electronic device including a thermoelectric conversion device. [Background technology]

[0002] Patent Document 1, Patent Document 2, and Non-Patent Document 1 disclose a periodic structure composed of a plurality of through holes. In this periodic structure, the through holes are regularly arranged in a period within the order of nanometers (1 nm to 1000 nm range) when the thin film is viewed in a plan view. This periodic structure is a type of phononic crystal structure. This type of phononic crystal structure usually has a unit cell, which is the smallest unit that constitutes the arrangement of through holes. The phononic crystal structure can reduce the thermal conductivity of the thin film. The thermal conductivity of the thin film can also be reduced by, for example, making the thin film porous. This is because the voids introduced into the thin film by making it porous reduce the thermal conductivity of the thin film. However, the phononic crystal structure can reduce the thermal conductivity of the base material itself that constitutes the thin film. For this reason, a further reduction in thermal conductivity is expected compared to simple porosity.

[0003] Thermoelectric conversion elements having a thermoelectric conversion part containing a thermoelectric conversion material are known. By using a thermoelectric conversion element, a thermoelectric conversion device can be constructed. The thermoelectric conversion device makes it possible to cool and / or heat an object by utilizing the Peltier effect. Patent Document 3 discloses a thermoelectric conversion element having a p-type thermoelectric conversion material and an n-type thermoelectric conversion material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2017 / 0047499 [Patent Document 2] US Patent Application Publication No. 2017 / 0069818 [Patent Document 3] International Publication No. 2011 / 048634 [Non-patent literature]

[0005] [Non-Patent Document 1] Nomura et al., "Impeded thermal transport is Si multiscale hierarchical architectures with phononic crystal nanostructures", Physical Review B 91, 205422 (2015) Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure provides a thermoelectric conversion device that has a high degree of freedom in controlling the cooling and / or heating of an object, such as being suitable for maintaining the change in temperature of the object within a predetermined range. [Means for solving the problem]

[0007] The present disclosure provides the following thermoelectric conversion device. A thermoelectric conversion device, An insulating layer; and a thermoelectric conversion module provided on the insulating layer, Where: The thermoelectric conversion module includes a first thermoelectric conversion region and a second thermoelectric conversion region, The first thermoelectric conversion region includes one or more thermoelectric conversion elements, a first connection electrode, and a second connection electrode, the thermoelectric conversion element in the first thermoelectric conversion region is electrically connected to the first connection electrode and the second connection electrode, and is located on an electrical path connecting the first connection electrode and the second connection electrode; The second thermoelectric conversion region includes one or more thermoelectric conversion elements, a third connection electrode, and a fourth connection electrode, the thermoelectric conversion element in the second thermoelectric conversion region is electrically connected to the third connection electrode and the fourth connection electrode, and is located on an electrical path connecting the third connection electrode and the fourth connection electrode; Each of the thermoelectric conversion elements includes a thermoelectric conversion portion, The thermoelectric conversion portion of at least one of the thermoelectric conversion elements includes a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes; The penetration direction of the plurality of through holes in the phononic crystal structure is approximately parallel to a direction perpendicular to a main surface of the insulating layer. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a thermoelectric conversion device that has a high degree of freedom in controlling the cooling and / or heating of an object, for example, being suitable for maintaining the change in temperature of the object within a predetermined range. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1A is a plan view illustrating a schematic diagram of an example of a thermoelectric conversion device according to the present disclosure. [Figure 1B] FIG. 1B is a cross-sectional view showing cross section 1B-1B of the thermoelectric conversion device of FIG. 1A. [Diagram 2] FIG. 2 is a cross-sectional view that illustrates a schematic example of a thermoelectric conversion section in a thermoelectric conversion element that can be included in a thermoelectric conversion device according to the present disclosure. [Diagram 3] FIG. 3 is a cross-sectional view that illustrates a schematic diagram of another example of a thermoelectric conversion section in a thermoelectric conversion element that can be included in a thermoelectric conversion device according to the present disclosure. [Figure 4] FIG. 4 is a plan view of the thermoelectric conversion section in FIG. 3 as viewed from the first phononic crystal layer side. [Diagram 5] FIG. 5 is a plan view of the thermoelectric conversion section in FIG. 3 viewed from the second phononic crystal layer side. [Figure 6A] FIG. 6A is a schematic diagram showing an example of a unit cell of a phononic crystal structure that a thermoelectric conversion element can have. [Figure 6B]FIG. 6B is a schematic diagram showing another example of a unit lattice of a phononic crystal structure that the thermoelectric conversion element may have. [Figure 6C] FIG. 6C is a schematic diagram showing yet another example of a unit lattice of a phononic crystal structure that the thermoelectric conversion element can have. [Figure 6D] FIG. 6D is a schematic diagram showing another example of a unit lattice of a phononic crystal structure that the thermoelectric conversion element can have. [Figure 7] FIG. 7 is a plan view that illustrates a schematic example of a phononic crystal structure that a thermoelectric conversion element may have. [Figure 8A] FIG. 8A is a schematic diagram showing a unit cell and its orientation in a first domain included in the phononic crystal structure of FIG. [Figure 8B] FIG. 8B is a schematic diagram showing a unit cell and its orientation in the second domain included in the phononic crystal structure of FIG. [Figure 9] FIG. 9 is an enlarged view of region R1 of the phononic crystal structure of FIG. [Figure 10] FIG. 10 is a plan view that illustrates a schematic diagram of another example of a phononic crystal structure that the thermoelectric conversion element may have. [Figure 11] FIG. 11 is an enlarged view of region R2 of the phononic crystal structure of FIG. [Figure 12] FIG. 12 is a plan view that illustrates a schematic diagram of still another example of a phononic crystal structure that the thermoelectric conversion element may have. [Figure 13] FIG. 13 is an enlarged view of region R3 of the phononic crystal structure of FIG. [Figure 14] FIG. 14 is a plan view that illustrates a schematic diagram of still another example of a phononic crystal structure that a thermoelectric conversion element can have. [Figure 15] FIG. 15 is a plan view that illustrates a schematic example of another phononic crystal structure that the thermoelectric conversion element may have. [Figure 16] FIG. 16 is a plan view that illustrates a schematic example of another phononic crystal structure that the thermoelectric conversion element may have. [Figure 17A]FIG. 17A is a schematic diagram showing an example of a unit lattice of a phononic crystal structure that a thermoelectric conversion element can have. [Figure 17B] FIG. 17B is a schematic diagram showing another example of a unit lattice of a phononic crystal structure that the thermoelectric conversion element may have. [Figure 18] FIG. 18 is a plan view that illustrates a schematic example of another phononic crystal structure that the thermoelectric conversion element may have. [Figure 19] FIG. 19 is a plan view that illustrates a schematic example of another phononic crystal structure that the thermoelectric conversion element may have. [Figure 20A] FIG. 20A is a plan view that illustrates an example of a phononic crystal layer that a thermoelectric conversion element can have. [Figure 20B] FIG. 20B is a cross-sectional view showing cross section 20B-20B of the phononic crystal layer of FIG. 20A. [Figure 21] FIG. 21 is a cross-sectional view that illustrates a schematic example of another thermoelectric conversion section in a thermoelectric conversion element that can be included in a thermoelectric conversion device of the present disclosure. [Figure 22A] FIG. 22A is a plan view diagrammatically illustrating another example of a phononic crystal layer that the thermoelectric conversion element can have. [Figure 22B] FIG. 22B is a cross-sectional view showing section 22B-22B of the phononic crystal layer of FIG. 22A. [Figure 23] FIG. 23 is a cross-sectional view that illustrates a schematic example of a thermoelectric conversion section in a thermoelectric conversion element that can be included in a thermoelectric conversion device of the present disclosure. [Figure 24A] FIG. 24A is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24B] FIG. 24B is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24C] FIG. 24C is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24D]FIG. 24D is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24E] FIG. 24E is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24F] FIG. 24F is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24G] FIG. 24G is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Fig. 24H] FIG. 24H is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24I] FIG. 24I is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24J] FIG. 24J is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24K] FIG. 24K is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24L] FIG. 24L is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24M] FIG. 24M is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 24N] FIG. 24N is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Fig. 24O] FIG. 24O is a schematic cross-sectional view for explaining an example of a method for manufacturing a thermoelectric conversion element that can be provided in a thermoelectric conversion device of the present disclosure. [Figure 25A]FIG. 25A is a plan view diagrammatically illustrating another example of a thermoelectric conversion device according to the present disclosure. [Figure 25B] FIG. 25B is a cross-sectional view showing cross section 25B-25B of the thermoelectric converter of FIG. 25A. [Figure 25C] FIG. 25C is a cross-sectional view showing a cross section 25C-25C of the thermoelectric conversion device of FIG. 25A. [Figure 26A] FIG. 26A is a cross-sectional view illustrating a schematic diagram of still another example of a thermoelectric conversion device according to the present disclosure. [Figure 26B] FIG. 26B is a cross-sectional view showing a cross section 26B-26B of the thermoelectric conversion device of FIG. 26A. [Figure 27] FIG. 27 is a flowchart illustrating an example of a control method of the present disclosure. [Figure 28] FIG. 28 is a graph showing a voltage application pattern in an example of the control method of the present disclosure. [Figure 29] FIG. 29 is a graph showing a voltage application pattern in an example of the control method of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Findings on which this disclosure is based) The thermoelectric conversion device of the present disclosure includes a thermoelectric conversion module including a plurality of thermoelectric conversion regions. Each thermoelectric conversion region can be controlled independently via a connection electrode included in each region. For example, by performing different controls between a thermoelectric conversion region closer to an object and a thermoelectric conversion region farther from the object, the degree of freedom in controlling cooling and / or heating of the object can be increased.

[0011] In addition, the thermoelectric conversion device of the present disclosure includes a thermoelectric conversion element having a thermoelectric conversion unit having a phononic crystal structure. This allows the heat insulating performance of a thermoelectric conversion module including the element to be improved, typically the heat insulating performance in both the thickness direction and the in-plane direction of the thermoelectric conversion module and the thermoelectric conversion device. The heat insulating performance improved in the thickness direction improves the thermoelectric conversion efficiency of the thermoelectric conversion module. The heat insulating performance improved in the in-plane direction improves the degree of freedom of the control pattern of each region when controlling a plurality of thermoelectric conversion regions independently. These points synergistically contribute to improving the degree of freedom of control of cooling and / or heating of the object.

[0012] (Embodiments of the present disclosure) Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. Note that the embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component arrangement and connection forms, process conditions, steps, and order of steps shown in the following embodiments are examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, components that are not described in the independent claims showing the highest concept are described as optional components. Note that each figure is a schematic diagram and is not necessarily illustrated strictly.

[0013] [Thermoelectric conversion device] (First embodiment) A thermoelectric converter according to a first embodiment is shown in FIG. 1A and FIG. 1B. FIG. 1B shows a cross section 1B-1B of the thermoelectric converter 1 of FIG. 1A. The thermoelectric converter 1 of FIG. 1A and FIG. 1B includes an insulating layer 7 and a thermoelectric conversion module 2. The thermoelectric conversion module 2 is provided on the insulating layer 7. The thermoelectric conversion module 2 is layered. The thermoelectric conversion module 2 includes a first thermoelectric conversion region A and a second thermoelectric conversion region B. The first thermoelectric conversion region A is square when viewed from a direction X perpendicular to the main surface of the insulating layer 7. The second thermoelectric conversion region B has a square outer shape when viewed from the direction X and surrounds the first thermoelectric conversion region A. The direction X is also the thickness direction of the thermoelectric converter 1 and the thickness direction of the thermoelectric conversion module 2. The first thermoelectric conversion region A and the second thermoelectric conversion region B are adjacent to each other. The first thermoelectric conversion region A and the second thermoelectric conversion region B are in the same layer. However, the arrangement of the thermoelectric conversion regions included in the thermoelectric conversion module in the thermoelectric conversion device of the present disclosure and the shape as viewed from the direction X are not limited to the above examples.

[0014] The first thermoelectric conversion region A includes one or more thermoelectric conversion elements 21 (21a), a first connection electrode 11, and a second connection electrode 12. The thermoelectric conversion elements 21a in the first thermoelectric conversion region A are electrically connected to the first connection electrode 11 and the second connection electrode 12. The thermoelectric conversion elements 21a are located on an electrical path connecting the first connection electrode 11 and the second connection electrode 12. When the first thermoelectric conversion region A includes two or more thermoelectric conversion elements 21a, the electrical connection between each thermoelectric conversion element 21a and the first connection electrode 11 or the second connection electrode 12 may be a direct connection or an indirect connection via another thermoelectric conversion element 21a. The two or more thermoelectric conversion elements 21a may be electrically connected to each other in series between the first connection electrode 11 and the second connection electrode 12. However, the form of the electrical connection between the thermoelectric conversion elements 21a between the first connection electrode 11 and the second connection electrode 12 is not limited. For example, a mixture of series connection and parallel connection is also possible. By applying a voltage via the first connection electrode 11 and the second connection electrode 12, the thermoelectric conversion element 21a and the first thermoelectric conversion region A operate as a Peltier element and a Peltier module, respectively. The Peltier module is, for example, a Peltier cooling module, a Peltier cooling / heating module, or a Peltier heating module.

[0015] The second thermoelectric conversion region B includes one or more thermoelectric conversion elements 21 (21b), a third connection electrode 13, and a fourth connection electrode 14. The thermoelectric conversion elements 21b in the second thermoelectric conversion region B are electrically connected to the third connection electrode 13 and the fourth connection electrode 14. In the example of FIG. 1A and FIG. 1B, the electrical connection between each thermoelectric conversion element 21b and the third connection electrode 13 or the fourth connection electrode 14 is direct or indirect via another thermoelectric conversion element 21b. The thermoelectric conversion element 21b is located on an electrical path connecting the third connection electrode 13 and the fourth connection electrode 14. In the example of FIG. 1A and FIG. 1B, two or more thermoelectric conversion elements 21b are electrically connected to each other in series between the third connection electrode 13 and the fourth connection electrode 14. However, the form of electrical connection between the thermoelectric conversion elements 21b between the third connection electrode 13 and the fourth connection electrode 14 is not limited to the above example. For example, series connections and parallel connections may be mixed. By applying a voltage via the third connection electrode 13 and the fourth connection electrode 14, the thermoelectric conversion element 21b and the second thermoelectric conversion region B operate as a Peltier element and a Peltier module, respectively.

[0016] In the first thermoelectric conversion region A and the second thermoelectric conversion region B, two or more thermoelectric conversion elements 21 are typically arranged in an array.

[0017] The form of electrical connection between the thermoelectric conversion elements 21 in the first thermoelectric conversion region A and the second thermoelectric conversion region B may be the same or different.

[0018] 1A and 1B, the number of the first connection electrodes 11, the second connection electrodes 12, the third connection electrodes 13, and the fourth connection electrodes 14 is 1. However, the number of each connection electrode may be 2 or more.

[0019] The voltage applied between the first connection electrode 11 and the second connection electrode 12 and the voltage applied between the third connection electrode 13 and the fourth connection electrode 14 can be controlled independently. This enables independent control of the first thermoelectric conversion region A and the second thermoelectric conversion region B. For example, a first voltage may be applied to the first thermoelectric conversion region A, and a second voltage having an application pattern different from that of the first voltage may be applied to the second thermoelectric conversion region B.

[0020] The thermoelectric converter 1 in FIG. 1A and FIG. 1B further includes a substrate (base layer) 6 and a protective layer 8. The protective layer 8 is provided on a thermoelectric conversion module 2. The protective layer 8 is located on the outermost layer of the thermoelectric converter 1 (the outermost layer on the side opposite to the substrate 6). The thermoelectric converter 1 has a structure in which a substrate 6, an insulating layer 7, a thermoelectric conversion module 2, and a protective layer 8 are laminated in this order. The first connection electrode 11, the second connection electrode 12, the third connection electrode 13, and the fourth connection electrode 14 reach the upper surface of the protective layer 8 as via wiring embedded in a through hole extending in the direction X through the protective layer 8, and are exposed on the upper surface. The exposed ends of the connection electrodes can be, for example, connection points with a control device and / or a control module that controls the voltage applied to the first thermoelectric conversion region A and the second thermoelectric conversion region B.

[0021] The thermoelectric conversion element 21 includes a p-type thermoelectric conversion unit 22 and an n-type thermoelectric conversion unit 23, which are thermoelectric conversion units, as well as a first electrode 24, a second electrode 25, and a third electrode 26. One end of the p-type thermoelectric conversion unit 22 and one end of the n-type thermoelectric conversion unit 23 are electrically connected via the first electrode 24. The other end of the p-type thermoelectric conversion unit 22 is electrically connected to the second electrode 25. The other end of the n-type thermoelectric conversion unit 23 is electrically connected to the third electrode 26. One electrode selected from the second electrode 25 and the third electrode 26 is located on the electrical path connecting the connection electrodes and is located on the upstream side of the path. The other electrode selected from the second electrode 25 and the third electrode 26 is located on the electrical path connecting the connection electrodes and is located on the downstream side of the path. In other words, a voltage can be applied to the thermoelectric conversion element 21 via the second electrode 25 and the third electrode 26. Between adjacent thermoelectric conversion elements 21, the second electrode 25 and the third electrode are electrically connected to each other. The upstream and downstream of the electrical path may be determined based on the direction of the current flowing through the path when a representative voltage is applied to the thermoelectric conversion region. In the thermoelectric conversion element 21, the direction connecting the pair of electrodes sandwiching the thermoelectric conversion unit is usually the direction X. In other words, the control direction of the heat flow in the thermoelectric conversion element 21 and the thermoelectric conversion device 1 is usually the direction X. In the thermoelectric conversion element 21 of FIG. 1A and FIG. 1B, an insulating part 27 is arranged between the p-type thermoelectric conversion part 22 and the n-type thermoelectric conversion part 23, and this arrangement maintains electrical insulation between the two thermoelectric conversion parts 22 and 23.

[0022] The p-type thermoelectric conversion section 22 and / or the n-type thermoelectric conversion section 23 of the thermoelectric conversion element 21, typically the p-type thermoelectric conversion section 22 and the n-type thermoelectric conversion section 23, are provided with a phononic crystal layer. The phononic crystal layer has a plurality of through holes arranged regularly. The penetration direction of the plurality of through holes in the phononic crystal structure is approximately parallel to the direction X perpendicular to the main surface of the insulating layer 7. The phononic crystal layer is, for example, a first phononic crystal layer and a second phononic crystal layer described later. The through holes are, for example, a first through hole and a second through hole described later. In the first embodiment, all the thermoelectric conversion elements 21 are provided with a phononic crystal layer. However, all the thermoelectric conversion elements 21 may not be provided with a phononic crystal layer. In this specification, the term "approximately parallel" means that even if the relationship between two directions is deviated from parallelism by, for example, 5 degrees or less, preferably 3 degrees or less, more preferably 1 degree or less, the relationship is considered to be parallel.

[0023] In insulators and semiconductors, heat is mainly carried by lattice vibrations called phonons. The thermal conductivity of a material made of an insulator or semiconductor is determined by the dispersion relationship of the phonons that the material has. The dispersion relationship of phonons means the relationship between frequency and wave number, or band structure. In insulators and semiconductors, phonons that carry heat span a wide frequency band from 100 GHz to 10 THz. This frequency band is the thermal band. The thermal conductivity of a material is determined by the dispersion relationship of phonons in the thermal band. According to the above phononic crystal structure, the dispersion relationship of the phonons that the material has can be controlled by the periodic structure of the through holes. In other words, according to the phononic crystal structure, the thermal conductivity itself of a material, for example, the base material of a thermoelectric conversion part, can be controlled. In particular, the formation of a phononic band gap (PBG) by the phononic crystal structure can greatly reduce the thermal conductivity of the material. Phonons cannot exist in the PBG. For this reason, the PBG located in the thermal band can become a gap in thermal conduction. In addition, the slope of the phonon dispersion curve is reduced by the PBG even in frequency bands other than the PBG. The reduction in the slope reduces the group velocity of phonons and the thermal conduction rate. These points greatly contribute to the reduction of the thermal conductivity of the material itself.

[0024] <Phononic crystal structure> The phononic crystal structure that the thermoelectric conversion section of the thermoelectric conversion element 21 may have will be described below, taking the p-type thermoelectric conversion section 22 as an example of the thermoelectric conversion section. The n-type thermoelectric conversion section 23 may also have the phononic crystal structure described below.

[0025] An example of the p-type thermoelectric conversion section 22 is shown in FIG. 2. The p-type thermoelectric conversion section 22 in FIG. 2 includes a first phononic crystal layer 44 having a first phononic crystal structure with a plurality of first through holes 43 regularly arranged. The p-type thermoelectric conversion section 22 in FIG. 2 is a single-layer structure of the first phononic crystal layer 44. The penetration direction of the first phononic crystal structure and the plurality of first through holes 43 in the first phononic crystal layer 44 is a direction connecting one end 41 and the other end 42 in the p-type thermoelectric conversion section 22. The first electrode 24 is disposed at the one end 41. The second electrode 25 is disposed at the other end 42. This direction is approximately perpendicular to the connection surface with the first electrode 24 and the connection surface with the second electrode 25 in the p-type thermoelectric conversion section 22. In this specification, the term "approximately perpendicular" means that the relationship between two directions is considered to be perpendicular even if the relationship deviates from perpendicular by, for example, 5 degrees or less, preferably 3 degrees or less, and more preferably 1 degree or less.

[0026] Another example of the p-type thermoelectric conversion section 22 is shown in FIG. 3. The p-type thermoelectric conversion section 22 in FIG. 3 further includes a second phononic crystal layer 46 having a second phononic crystal structure including a plurality of regularly arranged second through holes 45 in addition to the first phononic crystal layer 44. The first phononic crystal layer 44 and the second phononic crystal layer 46 are stacked in a direction connecting one end 41 and the other end 42 of the p-type thermoelectric conversion section 22. The first phononic crystal layer 44 and the second phononic crystal layer 46 are stacked in a direction X. The penetration direction of the first phononic crystal structure and the plurality of first through holes 43 in the first phononic crystal layer 44 and the penetration direction of the second phononic crystal structure and the plurality of second through holes 45 in the second phononic crystal layer 46 are approximately parallel to each other. 3 is a laminated structure of a first phononic crystal layer 44 and a second phononic crystal layer 46. The first phononic crystal layer 44 and the second phononic crystal layer 46 are in contact with each other.

[0027] The PBG distribution is three-dimensional, and in the phononic crystal layer, it is expected that the heat flow can be controlled not only in the in-plane direction but also in the thickness direction, and that this control will reduce the thermal conductivity. In Figs. 2 and 3, the "thickness direction in the phononic crystal layer" means the penetration direction of the regularly arranged multiple through holes. In the p-type thermoelectric conversion section 22 in Fig. 3, at least two phononic crystal layers are stacked in the thickness direction. The increase in thickness due to stacking is expected to more reliably control the heat flow in the thickness direction in the p-type thermoelectric conversion section 22.

[0028] The first phononic crystal layer 44 and the second phononic crystal layer 46 have a thickness of, for example, 10 nm or more and 500 nm or less. When the p-type thermoelectric conversion section 22 has two or more phononic crystal layers, the thicknesses of the phononic crystal layers may be the same as or different from each other.

[0029] There is no limitation on the number of phononic crystal layers included in the p-type thermoelectric conversion section 22. When the p-type thermoelectric conversion section 22 includes two or more phononic crystal layers, the phononic crystal layers may be stacked so as to be in contact with each other, or may be stacked via another member. The other member may be, for example, an oxide film such as SiO2, or a buffer layer described later.

[0030] FIG. 4 shows a plan view of the p-type thermoelectric conversion section 22 of FIG. 3 seen from the side of the first phononic crystal layer 44. FIG. 5 shows a plan view of the p-type thermoelectric conversion section 22 of FIG. 3 seen from the side of the second phononic crystal layer 46. In the p-type thermoelectric conversion section 22 of FIG. 3, FIG. 4, and FIG. 5, the configuration of the first phononic crystal structure of the first phononic crystal layer 44 is different from the configuration of the second phononic crystal structure of the second phononic crystal layer 46. Specifically, the period P of the arrangement of the first through holes 43 is different from the period P of the arrangement of the second through holes 45. When the configuration of the first phononic crystal structure is different from the configuration of the second phononic crystal structure, usually, at least a part of the second through holes 45 does not communicate with the first through holes 43. However, in the p-type thermoelectric conversion section 22 having two or more phononic crystal layers, the configuration of each phononic crystal layer may be the same.

[0031] The thickness of the phononic crystal layers 44, 46, which corresponds to the length of the through holes 43, 45, may be twice or more the diameter of the through holes. In this case, the distance between the upper and lower surfaces of the phononic crystal layers 44, 46 can be increased. This allows the temperature difference between the upper and lower surfaces of the phononic crystal layers 44, 46 to be increased, thereby improving the thermoelectric conversion efficiency. In this specification, the "upper surface" and "lower surface" of the phononic crystal layer respectively mean one main surface when the phononic crystal layer is viewed in the penetrating direction of the through holes and the other main surface opposite to the one main surface. The "main surface" means the surface having the widest area. The upper limit of the thickness of the phononic crystal layers 44, 46 is, for example, 100 times or less the diameter of the through holes, and may be 80 times or less, 60 times or less, or 50 times or less.

[0032] The ratio of the total volume of the through holes 43, 45 included in each phononic crystal layer 44, 46 to the volume of each phononic crystal layer 44, 46, in other words, the porosity of the phononic crystal layer, may be 10% or more. In this case, the volume of the phononic crystal layers 44, 46 excluding the through holes 43, 45 can be reduced, and the PBG effect can be improved. This allows the thermal conductivity of the phononic crystal layers 44, 46 to be further reduced, and the thermoelectric conversion efficiency can be improved. The upper limit of the porosity of the phononic crystal layers 44, 46 is, for example, 90% or less, and may be 70% or less, 50% or less, or 40% or less.

[0033] The following are examples of cases in which the configuration of the first phononic crystal structure and the configuration of the second phononic crystal structure are different. A combination of a plurality of cases may also be used. The period P of the arrangement of the first through holes 43 and the period P of the arrangement of the second through holes 45 are different. The diameter D of the first through hole 43 and the diameter D of the second through hole 45 are different. The type of unit cell 91 formed by the first through holes 43 is different from the type of unit cell 91 formed by the second through holes 45 .

[0034] As shown in phononic crystal structure A described later, the arrangement of the first through holes 43 in the first phononic crystal structure and the arrangement of the second through holes 45 in the second phononic crystal structure are not necessarily constant throughout the phononic crystal layer. In consideration of this, the p-type thermoelectric conversion unit 22 may have the following forms in which the configuration of the first phononic crystal structure is different from the configuration of the second phononic crystal structure. The p-type thermoelectric conversion unit 22 may have a form in which the following forms are arbitrarily combined.

[0035] Form A: The first phononic crystal structure includes a domain A which is a phononic crystal region. The second phononic crystal structure includes a domain B which is a phononic crystal region. When viewed in the penetration direction of the first through holes 43 and the second through holes 45, domain A and domain B overlap. The period P of the arrangement of the first through holes 43 in domain A is different from the period of the arrangement of the second through holes 45 in domain B.

[0036] Form B: The first phononic crystal structure includes a domain A which is a phononic crystal region. The second phononic crystal structure includes a domain B which is a phononic crystal region. When viewed in the penetration direction of the first through hole 43 and the second through hole 45, domain A and domain B overlap. The diameter of the first through hole 43 in domain A is different from the diameter of the second through hole 45 in domain B.

[0037] Form C: The first phononic crystal structure includes a domain A which is a phononic crystal region. The second phononic crystal structure includes a domain B which is a phononic crystal region. When viewed in the penetration direction of the first through hole 43 and the second through hole 45, domain A and domain B overlap. The type of unit cell formed by the first through hole 43 in domain A is different from the type of unit cell formed by the second through hole 45 in domain B.

[0038] The domain, which is the phononic crystal region, has a period of arrangement of the through holes 43 and 45 of, for example, 25P in plan view, where P is the period of arrangement of the through holes 43 and 45. 2 To control the phonon dispersion relationship by the phononic crystal structure, the domain must have an area of ​​at least 25P 2 In a square domain in plan view, the side length may be 5×P or more, so that the area of ​​the domain is 25P 2 The above area can be secured.

[0039] The shape of each domain in plan view is not limited. The shape of each domain in plan view is, for example, a polygon including a triangle, a square, and a rectangle, a circle, an ellipse, or a composite shape of these. The shape of each domain in plan view may be indefinite. Furthermore, the number of domains in the phononic crystal structure is not limited. The size of each domain in the phononic crystal structure is not limited. One domain may extend over the entire phononic crystal layer. In this specification, "plan view" means viewing the phononic crystal layer in the penetrating direction of the through-hole.

[0040] The period P of the arrangement of the through holes 43, 45 is, for example, 1 nm or more and 300 nm or less. This is because the wavelength of heat-carrying phonons is mainly in the range of 1 nm to 300 nm. The period P is determined by the center-to-center distance between adjacent through holes 43, 45 in a plan view.

[0041] The diameter D of the through holes 43, 45 is expressed by the ratio D / P to the period P, and is, for example, D / P≧0.5. If the ratio D / P<0.5, the porosity in the phononic crystal structure is excessively reduced, and the heat flow may not be sufficiently controlled, for example, the thermal conductivity may not be sufficiently reduced. The upper limit of the ratio D / P is, for example, less than 0.9, since the adjacent through holes 43, 45 do not contact each other. The diameter D is the diameter of the opening of the through holes 43, 45. If the shape of the opening of the through holes 43, 45 is a circle in a plan view, the diameter D is the diameter of the circle. The shape of the opening of the through holes 43, 45 does not have to be a circle in a plan view. In this case, the diameter D is determined by the diameter of a virtual circle having the same area as the area of ​​the opening.

[0042] The type of unit lattice 91 formed by the regularly arranged through holes 43, 45 is, for example, a square lattice (FIG. 6A), a hexagonal lattice (FIG. 6B), a rectangular lattice (FIG. 6C), and a face-centered rectangular lattice (FIG. 6D). However, the type of unit lattice 91 is not limited to these examples.

[0043] The material M constituting the p-type thermoelectric conversion unit 22, the n-type thermoelectric conversion unit 23, and the phononic crystal layer that the p-type thermoelectric conversion unit 22 and the n-type thermoelectric conversion unit 23 may have is typically a semiconductor material doped with an impurity element to become an appropriate semiconductor type of p-type or n-type. Examples of the semiconductor material are silicon (Si), Ge, SiGe, SiC, ZnSe, CdSn, ZnO, GaAs, InP, and GaN. The material M may be a material other than a semiconductor material, and examples of such materials are TiN, SiN, and VO2. However, the material M is not limited to the above examples.

[0044] In addition, Si-based semiconductor materials generally have a relatively high thermal conductivity as semiconductor materials. For this reason, it has been difficult to achieve high thermoelectric conversion efficiency with conventional thermoelectric conversion elements having a thermoelectric conversion section made of Si-based semiconductor materials. On the other hand, in the thermoelectric conversion element 21, the thermoelectric conversion section has a phononic crystal layer. For this reason, in the thermoelectric conversion element 21 and the thermoelectric conversion device 1 including the same, it is possible to achieve high thermoelectric conversion efficiency even when the thermoelectric conversion section is made of Si-based semiconductor materials.

[0045] Furthermore, the fact that the thermoelectric conversion section can be made of a Si-based semiconductor material brings about, for example, the following advantages: The base substrate may be the substrate 6 . It is possible to form a thermoelectric conversion element and a thermoelectric conversion device including the element on a base substrate made of a Si-based semiconductor material, for example a Si wafer. It is possible to embed a thermoelectric conversion element and a thermoelectric conversion device inside a base substrate made of a Si-based semiconductor material. This makes it possible to form integrated circuits such as CPUs and GPUs on a base substrate in which a thermoelectric conversion element or a thermoelectric conversion device is embedded. This means that it is possible to manufacture electronic devices such as integrated circuit devices in which a Peltier cooling device is embedded. The integrated circuit device may be a semiconductor element in which a thermoelectric conversion device and an integrated circuit are integrated and housed in a single package.

[0046] The first phononic crystal structure and the second phononic crystal structure may have the following form. The phononic crystal structure includes a first domain and a second domain that are phononic crystal regions. The through holes in the first domain are regularly arranged in a first direction when viewed in a cross section perpendicular to the penetration direction of the through holes. The through holes in the second domain are regularly arranged in a second direction different from the first direction when viewed in a cross section perpendicular to the penetration direction of the through holes. Hereinafter, a phononic crystal structure including a plurality of types of domains divided according to the direction of arrangement in this manner will be referred to as a phononic crystal structure A. The direction of arrangement can be determined by the orientation of the unit cell.

[0047] According to the study by the present inventors, the degree of reduction in thermal conductivity brought about by the phononic crystal structure depends on the angle between the direction of heat transfer and the orientation of the unit lattice of the phononic crystal structure. This is believed to be because factors related to heat transfer, such as the bandwidth of the PBG, the number of PBGs, and the average group velocity of phonons, depend on the angle. Furthermore, regarding heat transfer, phonons flow in the direction from high temperature to low temperature on a macroscopic level. On the other hand, when focusing on a microscopic region on the order of nanometers, no directionality is observed in the direction in which phonons flow. In other words, the direction in which phonons flow is not uniform on a microscopic level.

[0048] The above-mentioned patent documents and non-patent documents disclose components having multiple phononic crystal regions with uniform unit lattice orientation. However, in these components, the interaction is maximized for phonons flowing in a specific direction in a microscopic sense, but the interaction is weak for phonons flowing in other directions. On the other hand, phononic crystal structure A has two or more phononic crystal regions with different unit lattice orientations. Therefore, it is possible to enhance the interaction with each phonon flowing in multiple directions in a microscopic sense. This feature provides a further improvement in the degree of freedom in controlling heat flow.

[0049] The following description relates to a phononic crystal structure A that may be possessed by at least one phononic crystal layer selected from the first phononic crystal layer 44 and the second phononic crystal layer 46. When multiple phononic crystal layers have the phononic crystal structure A, the specific configuration of the phononic crystal structure A possessed by each phononic crystal layer may be the same or different.

[0050] An example of the phononic crystal structure A is shown in FIG. 7. FIG. 7 shows a plan view of a part of the phononic crystal layer 56. The phononic crystal layer 56 can be at least one phononic crystal layer selected from the first phononic crystal layer 44 and the second phononic crystal layer 46. The phononic crystal layer 56 is, for example, a thin film having a thickness of 10 nm or more and 500 nm or less. The phononic crystal layer 56 is rectangular in plan view. The phononic crystal layer 56 is provided with a plurality of through holes 50 extending in the thickness direction of the phononic crystal layer 56. The phononic crystal structure A of the phononic crystal layer 56 is a two-dimensional phononic crystal structure in which the plurality of through holes 50 are regularly arranged in the in-plane direction.

[0051] The phononic crystal structure A has a first domain 51A and a second domain 51B which are phononic crystal regions. The first domain 51A has a phononic single crystal structure having a plurality of through holes 50 regularly arranged in a first direction in a plan view. The second domain 51B has a phononic single crystal structure having a plurality of through holes 50 regularly arranged in a second direction different from the first direction in a plan view. In each single crystal structure, the diameter and arrangement period of the plurality of through holes 50 are the same. In each single crystal structure, the orientations of the unit cells 91A, 91B of the regularly arranged plurality of through holes 50 are the same. The shapes of the first domain 51A and the second domain 51B are rectangular in a plan view. The shapes of the first domain 51A and the second domain 51B are the same in a plan view. The phononic crystal structure A is also a phononic polycrystalline structure 52 which is a complex of a plurality of phononic single crystal structures.

[0052] As shown in FIG. 8A and FIG. 8B, in the phononic crystal structure A, the orientation 53A of the unit cell 91A in the first domain 51A and the orientation 53B of the unit cell 91B in the second domain 51B are different from each other in plan view. The angle between the orientation 53A and the orientation 53B is, for example, 10 degrees or more in plan view. However, when the unit cell 91A and the unit cell 91B are the same and have n-fold rotational symmetry, the upper limit of the angle between the orientation 53A and the orientation 53B is less than 360 / n degrees. When the unit cell has n-fold rotational symmetry for multiple n, the maximum n is used as n that determines the upper limit of the angle. For example, a hexagonal lattice has 2-fold rotational symmetry, 3-fold rotational symmetry, and 6-fold rotational symmetry. In this case, "6" is used as n that determines the upper limit of the angle. That is, for unit cells 91A and 91B, which are hexagonal lattices, the angle between orientation 53A and orientation 53B is less than 60 degrees. Phononic crystal structure A has at least two or more phononic crystal regions whose unit cell orientations are different from each other. As long as this condition is satisfied, phononic crystal structure A may further include any phononic crystal region and / or a region not having a phononic crystal structure.

[0053] The orientation of the unit cell can be determined based on any rule. However, the same rule must be applied to determine the orientation of the unit cell between different domains. The orientation of the unit cell is, for example, the extension direction of a straight line that bisects the angle between two non-parallel sides that make up the unit cell. However, the two sides must be determined using the same rule between different domains.

[0054] FIG. 9 shows an enlarged view of the region R1 of the phononic crystal structure A in FIG. 7. At the interface 55 between the first domain 51A and the second domain 51B adjacent to each other, the orientations 53A and 53B of the unit cells 91A and 91B change. The interface 55 where the orientation of the unit cells changes brings about a large interface resistance against the heat flowing macroscopically through the phononic crystal structure A. This interface resistance is based on the mismatch of the phonon group velocity occurring between the first domain 51A and the second domain 51B. This interface resistance contributes to a reduction in the thermal conductivity in the phononic crystal layer 56 having the phononic crystal structure A. Note that the interface 55 in FIG. 9 extends linearly in a plan view. Moreover, the interface 55 extends in the width direction of the rectangular phononic crystal layer 56 in a plan view. The width direction can be a direction perpendicular to the extension direction of the center line of the phononic crystal layer 56 determined by the macro heat transfer direction. The interface 55 divides the phononic crystal structure A substantially perpendicular to the macroscopic heat transfer direction in plan view.

[0055] In the phononic crystal structure A of FIG. 7, the period P of the arrangement of the plurality of through holes 50 in the first domain 51A is equal to the period P of the arrangement of the plurality of through holes 50 in the second domain 51B.

[0056] In the phononic crystal structure A of FIG. 7, the diameters of the plurality of through holes 50 regularly arranged in the first domain 51A are equal to the diameters of the plurality of through holes 50 regularly arranged in the second domain 51B.

[0057] In the phononic crystal structure A in Fig. 7, the type of unit cell 91A in the first domain 51A is the same as the type of unit cell 91B in the second domain 51B. Both the unit cell 91A and the unit cell 91B in Fig. 7 are hexagonal lattices.

[0058] There is no limitation on the number of domains in the phononic crystal structure A. The greater the number of domains in the phononic crystal structure A, the greater the effect of the interface resistance due to the interfaces between the domains.

[0059] Further examples of phononic crystal structure A are given below.

[0060] In the polycrystalline structure 52 which is the phononic crystal structure A in Figures 10 and 11, an interface 55 between adjacent first domain 51A and second domain 51B extends in the direction of the long side of a rectangular phononic crystal layer 56 in a plan view. Except for this, the phononic crystal structure A in Figures 10 and 11 has a configuration similar to that of the phononic crystal structure A in Figure 7. Figure 11 is an enlarged view of region R2 in Figure 10.

[0061] 7 and 10, the size of the first domain 51A and the size of the second domain 51B are the same in plan view. However, the sizes of the first domain 51A and the second domain 51B of the phononic structure A may be different from each other in plan view.

[0062] In the polycrystalline structure 52 which is the phononic crystal structure A in FIG. 12 and FIG. 13, the first domain 51B is surrounded by the second domain 51A in a planar view. The outer shape of the first domain 51A is rectangular in a planar view. The shape of the second domain 51B is rectangular in a planar view. The size of the first domain 51A and the size of the second domain 51B are different in a planar view. An interface 55 between the second domain 51B and the first domain 51A surrounding the second domain 51B constitutes the outer edge of the second domain 51B in a planar view. Other than these points, the phononic crystal structure A in FIG. 12 and FIG. 13 has the same configuration as the phononic crystal structure A in FIG. 7. FIG. 13 is an enlarged view of the region R3 in FIG. 12.

[0063] In the phononic crystal structure A in FIG. 12 and FIG. 13, the interface 55 has a bent portion.

[0064] Furthermore, the phononic crystal structure A in FIGS. 12 and 13 has a second domain 51B that is not in contact with the side of the phononic crystal layer 56.

[0065] 14, a first domain 51A and a second domain 51B are arranged to be spaced apart from each other in a plan view. More specifically, in a plan view, a region 201 having no through-hole 50 is provided between the first domain 51A and the second domain 51B in the long side direction of the phononic crystal layer 56. Except for this, the phononic crystal structure A in FIG. 14 has a similar configuration to the phononic crystal structure A in FIG. 7.

[0066] In the polycrystalline structure 52 which is the phononic crystal structure A in FIG. 15, the first domain 51A and the second domain 51B are arranged apart from each other in a planar view. More specifically, in a planar view, a region 202 having randomly arranged through holes 50 is provided between the first domain 51A and the second domain 51B in the long side direction of the phononic crystal layer 56. In the region 202, the through holes 50 are not regularly arranged in a planar view. Alternatively, in the region 202, the area of ​​the region where the through holes 50 are regularly arranged in a planar view is, for example, 25P 2 7. Here, P is the period of the arrangement of the through holes 50. Except for this, the phononic crystal structure A in FIG. 15 has the same configuration as the phononic crystal structure A in FIG.

[0067] The polycrystalline structure 52, which is the phononic crystal structure A in FIG. 16, includes a plurality of domains 51A, 51B, 51C, 51D, 51E, 51F, and 51G having different shapes in plan view. In each domain, the period of the arrangement of the plurality of through holes 50 and the orientation of the unit cell are the same. However, the orientation of the unit cell is different between the domains. In addition, in plan view, the size and shape of each domain are different from each other. In this embodiment, there are more orientations of the unit cell when viewed as a whole of the phononic crystal structure A compared to the embodiments exemplified so far. Therefore, the effect of reducing the thermal conductivity based on the different orientations of the unit cell becomes more prominent. In addition, in this embodiment, the interface 55 between the domains extends in a plurality of random directions in plan view. Therefore, the effect of reducing the thermal conductivity based on the interface resistance becomes more prominent.

[0068] 16, an interface 55 between adjacent first and second domains 51A and 51B extends in a direction tilted from the width direction of the phononic crystal layer 56 in a plan view. The interface 55 also has a bent portion in a plan view.

[0069] The polycrystalline structure 52, which is the phononic crystal structure A, may include a first domain 51A and a second domain 51B in which the period P of the arrangement of the through holes 50 and / or the diameter D of the through holes 50 are different from each other. The diameter D of the through holes 50 in the first domain 51A shown in Fig. 17A is different from the diameter D of the through holes 50 in the second domain 51B shown in Fig. 17B. The period P of the arrangement of the through holes 50 in the first domain 51A shown in Fig. 17A is the same as the period P of the arrangement of the through holes 50 in the second domain 51B shown in Fig. 17B.

[0070] The phononic crystal structure A shown in FIG. 18 has a first domain 51A in which a plurality of through holes 50 having a relatively small period P and a diameter D are regularly arranged, and a second domain 51B in which a plurality of through holes 50 having a relatively large period P and a diameter D are regularly arranged. The phononic crystal structure A in FIG. 18 also has a region 92 having a plurality of through holes 50 having a relatively small period P and a diameter D, and a region 93 having a plurality of through holes 50 having a relatively large period P and a diameter D. The region 92 and the region 93 are adjacent to each other. The region 92 and the region 93 each have a different shape from each other in a plan view, and include a plurality of domains whose unit lattice orientations are different from each other, as in the example shown in FIG. 16. The region 92 and the region 93 also divide the phononic crystal structure A approximately parallel to the macroscopic heat transfer direction. In this embodiment, the frequency band of the PBG formed in the first domain 51A is different from the frequency band of the PBG formed in the second domain 51B, and therefore the effect of reducing the thermal conductivity is particularly remarkable.

[0071] The phononic crystal structure A shown in Fig. 19 includes a first domain 51A in which a plurality of through holes 50 having a relatively small period P and a diameter D are regularly arranged, and a second domain 51B in which a plurality of through holes 50 having a relatively large period P and a diameter D are regularly arranged. The phononic crystal structure A in Fig. 19 includes a plurality of domains having different shapes from each other in a planar view and having unit cell orientations different from each other. In this embodiment, the frequency band of the PBG formed in the first domain 51A is different from the frequency band of the PBG formed in the second domain 51B, and therefore the effect of reducing the thermal conductivity is particularly remarkable.

[0072] The shape of the phononic crystal layer 56 in plan view is, for example, a triangle, a polygon including a square and a rectangle, a circle, an ellipse, or a combination of these shapes. However, the shape of the phononic crystal layer 56 is not limited to the above examples.

[0073] The shape of the thermoelectric conversion unit in plan view is, for example, a triangle, a polygon including a square and a rectangle, a circle, an ellipse, or a composite shape thereof. However, the shape of the thermoelectric conversion unit is not limited to the above examples. The thermoelectric conversion unit may have a rectangular parallelepiped or cubic shape.

[0074] The thermoelectric conversion section may include two or more first phononic crystal layers 44 and / or two or more second phononic crystal layers 46. The thermoelectric conversion section may also include an additional phononic crystal layer having a phononic crystal structure whose specific configuration is different from the first phononic crystal structure and the second phononic crystal structure.

[0075] Another example of the phononic crystal layer 56 is shown in Figs. 20A and 20B. Fig. 20B shows a cross section 20B-20B of the phononic crystal layer 56 of Fig. 20A. The phononic crystal layer 56 shown in Figs. 20A and 20B further includes a plurality of pillars 61. The pillars 61 are columnar bodies extending linearly. Each of the pillars 61 fills the through-hole 50 of the phononic crystal layer 56. The circumferential surface of the pillars 61 is covered with an oxide film 62. In this embodiment, the through-hole 50, which is an empty hole, is filled with the pillars 61. For this reason, for example, the degree of freedom in controlling the characteristics of the through-hole 50 in the phononic crystal layer 56 in the penetration direction can be improved. More specifically, for example, in a thermoelectric conversion unit which is a laminated structure of two or more phononic crystal layers 56, it is possible to improve the electronic conductivity between one end 41 and the other end 42 while maintaining the low thermal conductivity based on the phononic crystal structure.

[0076] When the phononic crystal layer 56 in which the pillars 61 are filled and the pillars 61 are made of the same material, the peripheral surface of the pillars 61 is covered with an oxide film 62. When the phononic crystal layer 56 in which the pillars 61 are filled and the pillars 61 are made of different materials, the oxide film 62 is not necessarily required.

[0077] The phononic crystal layer 56 further including the pillars 61 is, for example, the first phononic crystal layer 44 and / or the second phononic crystal layer 46. The pillars 61 may be filled in both the first through holes 43 and the second through holes 45.

[0078] The pillars 61 are typically made of a semiconductor material. Examples of the material that makes up the pillars 61 include Si, SiGe, SiC, TiN, SiN, and VO2. However, the material that makes up the pillars 61 is not limited to the above examples.

[0079] The oxide film 62 is, for example, a SiO2 film. However, the oxide film 62 is not limited to the above example.

[0080] FIG. 21 shows an example of a p-type thermoelectric converter 22 including a first phononic crystal layer 44 and a second phononic crystal layer 46 filled with pillars 61. The p-type thermoelectric converter 22 in FIG. 21 includes the phononic crystal layer 56 shown in FIG. 20A and FIG. 20B as the first phononic crystal layer 44 and the second phononic crystal layer 46. The p-type thermoelectric converter 22 in FIG. 21 is a two-layer structure including two phononic crystal layers 56. A buffer layer 63 is disposed between the first phononic crystal layer 44 and the second phononic crystal layer 46. The material constituting the pillars 61 (excluding the oxide film 62) in the first phononic crystal layer 44 is the same as the material constituting the buffer layer 63. The material constituting the buffer layer 63 is the same as the material constituting the second phononic crystal layer 46 (excluding the pillars 61 and the oxide film 62).

[0081] Another example of the phononic crystal layer 56 is shown in Figures 22A and 22B. Figure 22B shows a cross section 22B-22B of the phononic crystal layer 56 of Figure 22A. The phononic crystal layer 56 shown in Figures 22A and 22B further includes a plurality of pillars 61. Each of the pillars 61 fills the through-hole 50 of the phononic crystal layer 56. The material constituting the pillars 61 is different from the material constituting the phononic crystal layer 56.

[0082] FIG. 23 shows an example of a p-type thermoelectric converter 22 including a first phononic crystal layer 44 and a second phononic crystal layer 46 filled with pillars 61. The p-type thermoelectric converter 22 in FIG. 23 is a three-layer structure having three phononic crystal layers 56, in which the first phononic crystal layer 44, the second phononic crystal layer 46, and the first phononic crystal layer 44 are arranged in this order. A first buffer layer 63A is arranged between the first phononic crystal layer 44, which is the bottom layer, and the second phononic crystal layer 46. A second buffer layer 63B is arranged between the second phononic crystal layer 46 and the first phononic crystal layer 44, which is the top layer. The material constituting the pillars 61 in the first phononic crystal layer 44 is the same as the material constituting the second buffer layer 63B. The material constituting the pillars 61 in the second phononic crystal layer 46 is the same as the material constituting the first buffer layer 63A. The material constituting the first phononic crystal layer 44 (excluding the pillars 61) is the same as the material constituting the first buffer layer 63A. The material constituting the second phononic crystal layer 46 (excluding the pillars 61) is the same as the material constituting the second buffer layer 63B. The p-type thermoelectric conversion section 22 in FIG. 23 is composed of two types of materials. Both of these two types of materials may be semiconductor materials.

[0083] The first connection electrode 11, the second connection electrode 12, the third connection electrode 13, the fourth connection electrode 14, the first electrode 24, the second electrode 25, and the third electrode 26 are made of a conductive material. The conductive material is typically a metal. The metal is, for example, chromium (Cr), aluminum (Al), gold (Au), silver (Ag), or copper (Cu). However, the conductive material is not limited to the above examples. At least one electrode selected from the first connection electrode 11, the second connection electrode 12, the third connection electrode 13, the fourth connection electrode 14, the first electrode 24, the second electrode 25, and the third electrode 26 may include a phononic crystal layer. The penetration direction of the multiple through holes in the phononic crystal layer may be approximately parallel to the direction X.

[0084] The substrate (base layer) 6 is typically made of a semiconductor material. The semiconductor material is, for example, Si. The substrate 6 may be a Si wafer. An oxide film may be formed on the upper surface of the substrate 6 made of Si. The oxide film is, for example, a SiO2 film. The oxide film may be an insulating layer 7. However, the configuration of the substrate 6 is not limited to the above example. For example, an integrated circuit may be embedded inside the substrate 6. The substrate 6 may have a layered structure in which multiple layers are stacked. At least a part of the substrate 6 may include a phononic crystal layer. The penetration direction of multiple through holes in the phononic crystal layer may be approximately parallel to the direction X.

[0085] The insulating layer 7 can function as a layer that maintains electrical insulation between the substrate 6 and the thermoelectric conversion module 2. The insulating layer 7 and the insulating section 27 are typically made of an insulating material. The insulating material is, for example, an oxide, a nitride, or an oxynitride of a metal containing Si. The insulating material may be SiO2. However, the insulating material is not limited to the above examples. At least one selected from the insulating layer 7 and the insulating section 27 may include a phononic crystal layer. The penetration direction of the multiple through holes in the phononic crystal layer may be approximately parallel to the direction X.

[0086] The protective layer 8 can function as a layer that protects the thermoelectric conversion device 1. The protective layer 8 is made of, for example, an insulating material. The protective layer 8 may be an insulating layer. The thermoelectric conversion module 2 can be a member sandwiched between a pair of insulating layers. Examples of the insulating material are as described above. The protective layer 8 may include a phononic crystal layer. The penetration direction of the multiple through holes in the phononic crystal layer may be approximately parallel to the direction X.

[0087] According to an embodiment in which the members other than the thermoelectric conversion section of the thermoelectric conversion element 21 also include a phononic crystal layer, it is possible to further reduce the thermal conductivity in the in-plane direction in the thermoelectric conversion device 1. This reduction makes it possible to further improve the thermoelectric conversion efficiency of the thermoelectric conversion device 1. This reduction also makes it possible to suppress the diffusion of heat in the in-plane direction, thereby further improving the degree of freedom in constructing an electronic device including the thermoelectric conversion device 1.

[0088] In addition, by reducing the thermal conductivity in the in-plane direction, for example, the temperature of the thermoelectric conversion region B that is not in contact with the heat source can be kept low, and in an advantageous embodiment, even constant, even when a heat source is placed in contact with the thermoelectric conversion region A. This also makes it possible to place a member that is easily affected by heat, such as an integrated circuit and / or an integrated circuit device, on the thermoelectric conversion region B and / or at a position further away from the thermoelectric conversion region A.

[0089] The thermoelectric conversion device 1 may further include a temperature detection module. In this case, for example, the first thermoelectric conversion region A and / or the second thermoelectric conversion region B can be controlled based on information about temperature acquired by the temperature detection module. The information about temperature is, for example, a temperature value, a temperature change rate, and a temperature history. However, the information about temperature is not limited to the above example. The thermoelectric conversion device 1 of FIG. 1A and FIG. 1B includes a temperature detection module 28 inside the protective layer 8. The temperature detection module 28 is located at the center of the thermoelectric conversion device 1 when viewed in the direction X. However, the position of the temperature detection module 28 is not limited to the above example. The temperature detection module 28 includes, for example, at least one selected from a thermocouple element, a resistance temperature detector, and a thermistor.

[0090] The thermoelectric conversion device 1 may further include a control module that controls the voltage applied to the first thermoelectric conversion region A and / or the second thermoelectric conversion region B. The control module may be configured, for example, by an integrated circuit. The control module may include a power source that applies a voltage to the first thermoelectric conversion region A and / or the second thermoelectric conversion region B, or may include a signal transmitter that sends a control signal to a power source provided separately from the control module. The control module may be connected to the temperature detection module 28.

[0091] The thermoelectric conversion device 1 may further include any member and / or module other than those described above. The thermoelectric conversion device of the present disclosure may include two or more thermoelectric conversion modules. The two or more thermoelectric conversion modules may be stacked in the direction X with an additional insulating layer sandwiched therebetween. At least one thermoelectric conversion module selected from the two or more thermoelectric conversion modules may be the thermoelectric conversion module 2 described above.

[0092] The thermoelectric conversion device 1 can be used as a Peltier cooling and / or heating device. The object to be cooled and / or heated by the thermoelectric conversion device 1 is, for example, a heat source. The heat source is, for example, an integrated circuit such as a CPU or GPU, or an integrated circuit device equipped with an integrated circuit. However, the object is not limited to the above examples. The heat generation amount of an integrated circuit changes irregularly depending on the load. For this reason, although it is desired that the temperature of the integrated circuit be constant, the temperature of the integrated circuit is forced to fluctuate irregularly. According to the thermoelectric conversion device 1, for example, the irregular fluctuation is suppressed, and the change in the temperature of the integrated circuit can be kept within a predetermined range. In other words, the thermoelectric conversion device 1 is particularly advantageous when the object is an integrated circuit and / or an integrated circuit device.

[0093] The thermoelectric converter 1 may be used as a Seebeck type power generator.

[0094] <Manufacturing method> The thermoelectric conversion device of the present disclosure can be manufactured by a combination of various thin film formation techniques, such as chemical vapor deposition (CVD), sputtering, and deposition, as well as various microfabrication and pattern formation techniques, such as electron beam lithography, photolithography, block copolymer lithography, selective etching, and chemo-mechanical polishing (CMP). Block copolymer lithography is suitable for forming phononic crystal structures.

[0095] An example of a method for manufacturing thermoelectric conversion element 21 having a phononic crystal layer will be described below with reference to Figures 24A to 24O. The method for manufacturing a thermoelectric conversion element that can be included in thermoelectric conversion device 1 is not limited to the following example.

[0096] 24A: A substrate 71 is prepared. An oxide film 72 is provided on the upper surface of the substrate 71. The oxide film 72 is, for example, a SiO2 film.

[0097] FIG. 24B: A metal layer 73 is formed on the oxide film 72. The metal layer 73 will later become the first electrode 24. The metal layer 73 is, for example, a Cr layer. The metal layer 73 is formed by, for example, sputtering. The thickness of the metal layer 73 is, for example, 50 nm.

[0098] 24C: A semiconductor layer 74 is formed on the metal layer 73. The semiconductor layer 74 is, for example, a polycrystalline Si layer. The semiconductor layer 74 is formed by, for example, CVD. The thickness of the semiconductor layer 74 is, for example, 200 nm.

[0099] FIG. 24D: A hard mask 75 is formed on the semiconductor layer 74. The hard mask 75 is, for example, a SiO2 layer. The hard mask 75 is, for example, formed by CVD. The thickness of the hard mask 75 is, for example, 30 nm. The hard mask 75 is used to form a phononic crystal structure on the semiconductor layer 74.

[0100] Figure 24E: A self-assembled film 76 of a block copolymer is formed on top of the hard mask 75. The self-assembled film 76 is used for block copolymer lithography to form phononic crystal structures.

[0101] FIG. 24F: A plurality of regularly-spaced through-holes 77 are formed in the hard mask 75 by block copolymer lithography.

[0102] 24G: By selective etching using hard mask 75 as a resist, a plurality of regularly arranged through holes 50 are formed in semiconductor layer 74 at positions corresponding to a plurality of through holes 77 in a plan view. The formed plurality of through holes 50 constitute a phononic crystal structure. Semiconductor layer 74 becomes phononic crystal layer 56.

[0103] FIG. 24H: The hard mask 75 and the self-assembled film 76 are removed.

[0104] Fig. 24I: An oxide film 62 is formed on the inner circumferential surface of the through hole 50 in the phononic crystal layer 56. The oxide film 62 is, for example, a SiO2 film. The oxide film 62 is formed by, for example, thermal oxidation. The thickness of the oxide film 62 is, for example, 1 nm.

[0105] Fig. 24J: A semiconductor is filled into the through-holes 50 in the phononic crystal layer 56 to form pillars 61 having oxide films 62 on their peripheral surfaces. The pillars 61 are made of, for example, polycrystalline Si. The pillars 61 are formed by, for example, CVD. At this time, a layer 78 made of the semiconductor material that constitutes the pillars 61 is formed on the phononic crystal layer 56.

[0106] Figure 24K: Layer 78 is removed, for example by CMP, thus forming phononic crystal layer 56 further comprising pillars 61.

[0107] 24L: Using a technique such as photolithography, impurity ions are implanted and doped into a partial region of phononic crystal layer 56 to form p-type thermoelectric converter 22. The impurity ions are, for example, boron ions.

[0108] Fig. 24M: Using a technique such as photolithography, impurity ions are implanted and doped into a region of phononic crystal layer 56 different from p-type thermoelectric conversion section 22 to form n-type thermoelectric conversion section 23. The impurity ions are, for example, phosphorus ions. P-type thermoelectric conversion section 22 and n-type thermoelectric conversion section 23 are spaced apart from each other.

[0109] FIG. 24N: The whole is heat treated (annealed) to activate the doped impurity ions.

[0110] FIG. 24O: A second electrode 25 is formed on the p-type thermoelectric conversion section 22. A third electrode 26 is formed on the n-type thermoelectric conversion section 23. The second electrode 25 and the third electrode 26 are made of, for example, Al. This forms the thermoelectric conversion element 21. The region between the p-type thermoelectric conversion section 22 and the n-type thermoelectric conversion section 23 in the phononic crystal layer 56 is left as the insulating section 27. The insulating section 27 has a phononic crystal structure having a plurality of regularly arranged through holes 50. According to this embodiment, the thermal conductivity in the in-plane direction of the element 21 between the p-type thermoelectric conversion section 22 and the n-type thermoelectric conversion section 23 can be reduced. This reduction also makes it possible to further improve the thermoelectric conversion efficiency of the thermoelectric conversion element 21 and the thermoelectric conversion device 1.

[0111] Second embodiment The thermoelectric converter of the second embodiment is shown in FIG. 25A, FIG. 25B, and FIG. 25C. FIG. 25B is a cross-sectional view showing a cross section 25B-25B of the thermoelectric converter 1 of FIG. 25A. The cross section 25B-25B includes the first thermoelectric conversion region A and the second thermoelectric conversion region B. FIG. 25C is a cross-sectional view showing a cross section 25C-25C of the thermoelectric converter 1 of FIG. 25A. The cross section 25C-25C includes the second thermoelectric conversion region B and the third thermoelectric conversion region C. The thermoelectric converter 1 of the second embodiment has a similar configuration to the thermoelectric converter 1 of the first embodiment, except that the thermoelectric conversion module 2 further includes the third thermoelectric conversion region C. The first thermoelectric conversion region A is a square when viewed from the direction X perpendicular to the main surface of the insulating layer 7. The thermoelectric conversion module 2 includes four second thermoelectric conversion regions B. Each of the second thermoelectric conversion regions B is rectangular when viewed from the direction X, and its short side is in contact with one side of the thermoelectric conversion region A. The first thermoelectric conversion region A and each of the second thermoelectric conversion regions B are adjacent to each other. The thermoelectric conversion module 2 includes four thermoelectric conversion regions C. Each of the third thermoelectric conversion regions C is square when viewed from the direction X, and its two sides are in contact with the long sides of different second thermoelectric conversion regions B. Each of the second thermoelectric conversion regions B and each of the thermoelectric conversion regions C are adjacent to each other. The distance between the center of gravity of the first thermoelectric conversion region A and the center of gravity of the third thermoelectric conversion region C is larger than the distance between the center of gravity of the first thermoelectric conversion region A and the center of gravity of the second thermoelectric conversion region B. In other words, the third thermoelectric conversion region C is located farther away from the first thermoelectric conversion region A than the second thermoelectric conversion region B. The first thermoelectric conversion region A, the second thermoelectric conversion region B, and the third thermoelectric conversion region C are in the same layer. The first thermoelectric conversion region A, the second thermoelectric conversion region B, and the third thermoelectric conversion region C combine to form a square thermoelectric conversion region as a whole when viewed from the direction X. The combination of the second thermoelectric conversion region B and the third thermoelectric conversion region C surrounds the first thermoelectric conversion region A when viewed from the direction X. However, the number of thermoelectric conversion regions provided in the thermoelectric conversion module in the thermoelectric conversion device disclosed herein, the manner of their arrangement, and the shape viewed from the direction X are not limited to the above example. In this specification, the "center of gravity" means the center of gravity when viewed from the direction X.

[0112] The third thermoelectric conversion region C includes two or more thermoelectric conversion elements 21 (21c), a fifth connection electrode 15, and a sixth connection electrode 16. The thermoelectric conversion element 21c of the third thermoelectric conversion region C is electrically connected to the fifth connection electrode 15 and the sixth connection electrode 16. The thermoelectric conversion element 21c is located on an electrical path connecting the connection electrodes 15, 16 included in the third thermoelectric conversion region C. When a voltage is applied via the connection electrodes 15, 16, the thermoelectric conversion element 21c and the third thermoelectric conversion region C operate as a Peltier element and a Peltier module, respectively. Other than the above, the third thermoelectric conversion region C may have a structure similar to that of the first thermoelectric conversion region A and / or the second thermoelectric conversion region B. In the thermoelectric conversion device 1 of the second embodiment, independent control is possible between the thermoelectric conversion regions A, B, and C. By increasing the number of independently controllable thermoelectric conversion regions, the degree of freedom in controlling the cooling and / or heating of an object can be further improved.

[0113] Third embodiment A thermoelectric converter according to a third embodiment is shown in Figs. 26A and 26B. Fig. 26B is a cross-sectional view showing a cross section 26B-26B of the thermoelectric converter 1 in Fig. 26A. The thermoelectric converter element 21 according to the first and second embodiments is an element having a p-type thermoelectric converter 22 and an n-type thermoelectric converter 23 in one element, which is called a π-type by those skilled in the art. The thermoelectric converter element that may be provided in the thermoelectric converter of the present disclosure is not limited to a π-type. The thermoelectric converter 1 according to the third embodiment is provided with a thermoelectric converter element 31 different from the π-type. Except for providing a thermoelectric converter element 31 instead of the thermoelectric converter element 21, the thermoelectric converter 1 according to the third embodiment has the same configuration as the thermoelectric converter 1 according to the first embodiment.

[0114] The thermoelectric conversion element 31 includes two thermoelectric conversion parts 32 and 33 adjacent to each other. The thermoelectric conversion parts 32 and 33 have the same conductivity type. In other words, the thermoelectric conversion element 31 includes two p-type thermoelectric conversion parts or n-type thermoelectric conversion parts adjacent to each other. The thermoelectric conversion element 31 also includes a fourth electrode 34, a fifth electrode 35, and a sixth electrode 36. One end of one thermoelectric conversion part 32 and one end of the other thermoelectric conversion part 33 are electrically connected via the fourth electrode 34. The fourth electrode 34 electrically connects the lower surface of the thermoelectric conversion part 32 and the upper surface of the thermoelectric conversion part 33. The fourth electrode 34 has a via wiring 37 (37a) extending in the direction X. The other end of the thermoelectric conversion part 32 is electrically connected to the fifth electrode 35. The other end of the thermoelectric conversion part 33 is electrically connected to the sixth electrode 36. One electrode selected from the fifth electrode 35 and the sixth electrode 36 is located on the upstream side of the electrical path connecting the connection electrodes. The other electrode selected from the fifth electrode 35 and the sixth electrode 36 is located on the downstream side of the electrical path connecting the connection electrodes. In other words, a voltage can be applied to the thermoelectric conversion element 31 via the fifth electrode 35 and the sixth electrode 36. In the thermoelectric conversion element 31, the direction connecting the pair of electrodes that sandwich the thermoelectric conversion unit is usually the direction X. When a current flows through the electrical path, the current flows in the two adjacent thermoelectric conversion units 32 and 33 in the same direction (see the arrows in FIG. 26B). The thermoelectric conversion element 31 is an element known to those skilled in the art as a uni-leg type.

[0115] 26 includes two or more thermoelectric conversion elements 31. The fifth electrodes 35 and sixth electrodes 36 between adjacent elements 31 are electrically connected through via wiring 37 (37b) extending in the X direction.

[0116] Thermoelectric conversion element 31 can have any configuration known as a unileg type, so long as the thermoelectric conversion portion has a phononic crystal layer.

[0117] [Method of controlling a thermoelectric conversion device] An example of a control method for the thermoelectric conversion device 1 is shown in FIG. 27. The control method in FIG. 27 includes a step of applying a first voltage to the first thermoelectric conversion region A and a second voltage to the second thermoelectric conversion region B. The first voltage and the second voltage have different application patterns. The control method in FIG. 27 is a type of method for performing independent control for each thermoelectric conversion region included in the thermoelectric conversion module 2 of the thermoelectric conversion device 1. When the thermoelectric conversion module 2 has three or more thermoelectric conversion regions, the above control can be performed by setting any one thermoelectric conversion region as the first thermoelectric conversion region A and any other thermoelectric conversion region as the second thermoelectric conversion region B.

[0118] Examples of different aspects of the application pattern are as follows: However, the different aspects of the application pattern are not limited to the following examples. At least one selected from the effective voltage value, the maximum voltage value, and the minimum voltage value is different. In the application of the pulse voltage, at least one selected from the pulse width, the period, the waveform, and the duty ratio is different.

[0119] When the thermoelectric conversion device includes the first temperature detection module 28, the application pattern of the first voltage and / or the second voltage may be controlled based on information about the temperature acquired by the temperature detection module 28.

[0120] An object to be cooled and / or heated by the thermoelectric conversion device 1 may be placed near the thermoelectric conversion device 1. The object is, for example, a heat source. Examples of the heat source are as described above. The object is, for example, placed on the opposite side of the thermoelectric conversion device 1 from the substrate 6. The object may be in contact with the thermoelectric conversion device 1. The object may be in contact with a protective layer, an insulating layer, or a thermoelectric conversion module of the thermoelectric conversion device 1. The object may be in contact with at least one thermoelectric conversion region selected from two or more thermoelectric conversion regions included in the thermoelectric conversion module, or may be in contact with only one thermoelectric conversion region. In this case, at least one selected from the following control A, control B, and control C may be performed.

[0121] Control A: The target object is equipped with a second temperature detection module, or a second temperature detection module is disposed between the target object and the thermoelectric conversion device 1, and the application pattern of the first voltage and / or the second voltage is controlled based on information on temperature acquired by the second temperature detection module. This allows for further improvement in the degree of freedom in controlling the cooling and / or heating of the target object.

[0122] Control B: The application pattern of the first voltage and / or the second voltage is controlled so that the voltage applied to the thermoelectric conversion region closer to the object, selected from the thermoelectric conversion region group included in the thermoelectric conversion module 2, changes more frequently than the voltage applied to the thermoelectric conversion region farther from the object. The thermoelectric conversion region group of the first and third embodiments is composed of the first thermoelectric conversion region A and the second thermoelectric conversion region B. The thermoelectric conversion region group of the second embodiment is composed of the first thermoelectric conversion region A, the second thermoelectric conversion region B, and the third thermoelectric conversion region C. However, in a thermoelectric conversion region group composed of three or more thermoelectric conversion regions, it is arbitrary which two thermoelectric conversion regions are defined as the first thermoelectric conversion region A and the second thermoelectric conversion region B to which the first voltage and the second voltage are applied. The distance between the thermoelectric conversion regions and the object can be defined as the distance between the centers of gravity of the respective regions. When the object is a heat source, the distance between the thermoelectric conversion region and the object may be defined as the distance between the point at which the temperature of the object is highest and the center of gravity of the thermoelectric conversion region.

[0123] Control C: The application pattern of the first voltage and / or the second voltage is controlled so that the change in temperature of the object falls within a predetermined range.

[0124] A more specific example of control B is shown in Figures 28 and 29. The control method of Figures 28 and 29 is a control method for a thermoelectric conversion device 1 having three thermoelectric conversion regions. In the control method of Figures 28 and 29, the voltage application pattern is controlled so that the voltage applied to thermoelectric conversion region A closest to the object changes more frequently than the voltage applied to thermoelectric conversion region B and thermoelectric conversion region C farther from the object. In addition, the voltage application pattern is controlled so that the voltage applied to thermoelectric conversion region B changes more frequently than the voltage applied to thermoelectric conversion region C farther from the object than thermoelectric conversion region B. Note that in the control of Figure 29, the application of voltage to thermoelectric conversion regions A and B is irregular.

[0125] The above control method is also a method for cooling and / or heating an object using a thermoelectric conversion device 1. In other words, from another aspect different from the above, the present disclosure provides a method for cooling and / or heating an object using a thermoelectric conversion device, the thermoelectric conversion device being a thermoelectric conversion device of the present disclosure, the method including a step of applying a first voltage to the first thermoelectric conversion region and applying a second voltage, the second voltage having an application pattern different from that of the first voltage, to the second thermoelectric conversion region in the thermoelectric conversion device. With this method, one or more of the above-mentioned controls can be implemented.

[0126] [Electronic Devices] From another aspect, the present disclosure provides an electronic device including an integrated circuit and a thermoelectric conversion device for cooling and / or heating the integrated circuit, the thermoelectric conversion device being the thermoelectric conversion device of the present disclosure. Examples of the electronic device are as described above. [Industrial Applicability]

[0127] The thermoelectric conversion device of the present disclosure can be used, for example, as a Peltier cooling device and / or a heating device. Examples of inventions derived from the above disclosure are listed below.

[0128] (Item 1) A thermoelectric conversion device, An insulating layer, and a thermoelectric conversion module provided on the insulating layer, Where: The thermoelectric conversion module includes a first thermoelectric conversion region and a second thermoelectric conversion region, The first thermoelectric conversion region includes at least one thermoelectric conversion element, a first connection electrode, and a second connection electrode; the at least one thermoelectric conversion element in the first thermoelectric conversion region is electrically connected to the first connection electrode and the second connection electrode, and is located on an electrical path connecting the first connection electrode and the second connection electrode; the second thermoelectric conversion region includes at least one thermoelectric conversion element, a third connection electrode, and a fourth connection electrode; the at least one thermoelectric conversion element in the second thermoelectric conversion region is electrically connected to the third connection electrode and the fourth connection electrode, and is located on an electrical path connecting the third connection electrode and the fourth connection electrode; Each of the at least one thermoelectric conversion element in the first thermoelectric conversion region and the at least one thermoelectric conversion element in the second thermoelectric conversion region includes a thermoelectric conversion unit; The thermoelectric conversion unit includes a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes; and A penetration direction of the plurality of through holes is approximately parallel to a direction perpendicular to a main surface of the insulating layer. Thermoelectric conversion device.

[0129] (Item 2) Item 1. A thermoelectric conversion device according to item 1, The at least one thermoelectric conversion element of the first thermoelectric conversion region includes two or more thermoelectric conversion elements. Thermoelectric conversion device.

[0130] (Item 3) Item 1. A thermoelectric conversion device according to item 1, The at least one thermoelectric conversion element of the second thermoelectric conversion region includes two or more thermoelectric conversion elements. Thermoelectric conversion device.

[0131] (Item 4) Item 2. The thermoelectric conversion device according to item 2, The two or more thermoelectric conversion elements are electrically connected to each other in series between the first connection electrode and the second connection electrode. Thermoelectric conversion device.

[0132] (Item 5) Item 3. The thermoelectric conversion device according to item 3, The two or more thermoelectric conversion elements are electrically connected to each other in series between the first connection electrode and the second connection electrode. Thermoelectric conversion device.

[0133] (Item 6) 6. The thermoelectric converter according to any one of items 1 to 5, The at least one thermoelectric conversion element of at least one thermoelectric conversion region selected from the group consisting of the first thermoelectric conversion region and the second thermoelectric conversion region, p-type thermoelectric conversion unit, n-type thermoelectric conversion unit, first electrode, A second electrode, and third electrode, Equipped with Where: the thermoelectric conversion unit includes the p-type thermoelectric conversion unit and the n-type thermoelectric conversion unit, one end of the p-type thermoelectric conversion unit and one end of the n-type thermoelectric conversion unit are electrically connected to each other via the first electrode, the other end of the p-type thermoelectric conversion unit is electrically connected to the second electrode, the other end of the n-type thermoelectric conversion unit is electrically connected to the third electrode, One electrode selected from the second electrode and the third electrode is located on the electrical path and upstream of the path; and the other electrode selected from the second electrode and the third electrode is located on the electrical path and downstream of the path; Thermoelectric conversion device.

[0134] (Item 7) 6. The thermoelectric converter according to any one of items 1 to 5, The at least one thermoelectric conversion element of at least one thermoelectric conversion region selected from the group consisting of the first thermoelectric conversion region and the second thermoelectric conversion region, Two p-type thermoelectric conversion units adjacent to each other; 4th electrode, A fifth electrode, and 6th electrode, Equipped with Where: The thermoelectric conversion unit includes the two p-type thermoelectric conversion units, one end of the one thermoelectric conversion unit and one end of the other thermoelectric conversion unit are electrically connected to each other via the fourth electrode, the other end of the one thermoelectric conversion unit is electrically connected to the fifth electrode, the other end of the other thermoelectric conversion unit is electrically connected to the sixth electrode, one electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and upstream of the path; The other electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and downstream of the path; and When a current flows through the electrical path, the current flows in the same direction in the two adjacent thermoelectric conversion units. Thermoelectric conversion device.

[0135] (Item 8) 6. The thermoelectric converter according to any one of items 1 to 5, The at least one thermoelectric conversion element of at least one thermoelectric conversion region selected from the group consisting of the first thermoelectric conversion region and the second thermoelectric conversion region, Two adjacent n-type thermoelectric conversion units; 4th electrode, A fifth electrode, and 6th electrode, Equipped with Where: The thermoelectric conversion unit includes the two n-type thermoelectric conversion units, one end of the one thermoelectric conversion unit and one end of the other thermoelectric conversion unit are electrically connected to each other via the fourth electrode, the other end of the one thermoelectric conversion unit is electrically connected to the fifth electrode, the other end of the other thermoelectric conversion unit is electrically connected to the sixth electrode, one electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and upstream of the path; The other electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and downstream of the path; and When a current flows through the electrical path, the current flows in the same direction in the two adjacent thermoelectric conversion units. Thermoelectric conversion device.

[0136] (Item 9) 9. The thermoelectric converter according to any one of items 1 to 8, The phononic crystal layer comprises a first phononic crystal layer and a second phononic crystal layer; the first phononic crystal layer has a first phononic crystal structure including a plurality of first through holes regularly arranged as the through holes; The second phononic crystal layer has a second phononic crystal structure including a plurality of regularly arranged second through holes as the through holes; and the first phononic crystal layer and the second phononic crystal layer are stacked in a direction perpendicular to a main surface of the insulating layer; Thermoelectric conversion device.

[0137] (Item 10) Item 9. The thermoelectric conversion device according to item 9, the first phononic crystal layer and the second phononic crystal layer are in contact with each other; Thermoelectric conversion device.

[0138] (Item 11) Item 11. The thermoelectric conversion device according to item 9 or 10, At least a portion of the second through hole does not communicate with the first through hole. Thermoelectric conversion device.

[0139] (Item 12) 12. The thermoelectric converter according to any one of claims 1 to 11, The phononic crystal structure includes a first domain and a second domain which are phononic crystal regions; the through holes in the first domain are regularly arranged in a first direction in a cross section perpendicular to a penetration direction of the through holes; and The plurality of through holes in the second domain are regularly arranged in a second direction different from the first direction in a cross section perpendicular to the penetration direction of the through holes. Thermoelectric conversion device.

[0140] (Item 13) 11. The thermoelectric converter according to any one of claims 1 to 10, the phononic crystal layer comprises a plurality of pillars; The pillar is a columnar body extending linearly, and Each of the pillars is filled in the through hole of the phononic crystal layer. Thermoelectric conversion device.

[0141] (Item 14) Item 14. The thermoelectric conversion device according to item 13, the phononic crystal layer filled with the pillars and the pillars are made of the same material; and The periphery of the pillar is covered with an oxide film. Thermoelectric conversion device.

[0142] (Item 15) 15. The thermoelectric converter according to any one of claims 1 to 14, Further comprising a temperature detection module. Thermoelectric conversion device.

[0143] (Item 16) 16. The thermoelectric converter according to any one of claims 1 to 15, Further comprising a control module that controls a voltage applied to at least one thermoelectric conversion region selected from the group consisting of the first thermoelectric conversion region and the second thermoelectric conversion region. Thermoelectric conversion device.

[0144] (Item 17) A method for controlling a thermoelectric conversion device, comprising: The method comprises: 17. The thermoelectric converter according to any one of items 1 to 16, applying a first voltage and a second voltage to the first thermoelectric conversion region and the second thermoelectric conversion region, respectively; Including, The first voltage and the second voltage have different application patterns. Control methods.

[0145] (Item 18) Item 17, a control method comprising: the thermoelectric conversion device includes a first temperature detection module; an application pattern of at least one voltage selected from the group consisting of the first voltage and the second voltage is controlled based on information regarding the temperature acquired by the first temperature detection module; Control methods.

[0146] (Item 19) Item 17 or 18, a control method comprising: An object to be cooled and / or heated by the thermoelectric conversion device is placed near the thermoelectric conversion device. Control methods.

[0147] (Item 20) Item 19, a control method comprising: The object includes a second temperature detection module, or a second temperature detection module is disposed between the object and the thermoelectric conversion device; and an application pattern of at least one voltage selected from the group consisting of the first voltage and the second voltage is controlled based on information regarding the temperature acquired by the second temperature detection module; Control methods.

[0148] (Item 21) 21. The control method according to item 19 or 20, An application pattern of at least one voltage selected from the group consisting of the first voltage and the second voltage is controlled so that a voltage applied to a thermoelectric conversion region selected from the first thermoelectric conversion region and the second thermoelectric conversion region and closer to the object changes more frequently than a voltage applied to a thermoelectric conversion region farther from the object. Control methods.

[0149] (Item 22) 22. The control method according to any one of items 17 to 21, an application pattern of at least one voltage selected from the group consisting of the first voltage and the second voltage is controlled so that a change in temperature of the object falls within a predetermined range; Control methods.

[0150] (Item 23) 23. The control method according to any one of items 17 to 22, The object is a heat source. Control methods.

[0151] (Item 24) A method for cooling and / or heating an object using a thermoelectric conversion device, comprising: The thermoelectric conversion device is the thermoelectric conversion device according to any one of items 1 to 16, The method includes applying a first voltage and a second voltage to the first thermoelectric conversion region and the second thermoelectric conversion region, respectively, in the thermoelectric conversion device; The first voltage and the second voltage have different application patterns. method.

[0152] (Item 25) 1. An electronic device comprising: Integrated circuits, and a thermoelectric conversion device for cooling and / or heating the integrated circuit; The thermoelectric conversion device is the thermoelectric conversion device according to any one of items 1 to 16. Electronic devices. [Explanation of symbols]

[0153] 1 Thermoelectric conversion device 2 Thermoelectric conversion module 6 Substrate 7 Insulating layer 8 Protective layer A First thermoelectric conversion area B Second thermoelectric conversion region 11 First connection electrode 12 Second connection electrode 13 Third connection electrode 14 Fourth connection electrode 21 Thermoelectric conversion element (π type) 22 p-type thermoelectric conversion unit 23 n-type thermoelectric conversion section 24 1st electrode 25 2nd electrode 26 3rd electrode 27 Insulation 28 Temperature Detection Module 31 Thermoelectric conversion element (Unileg type) 32,33 Thermoelectric conversion section 34 4th electrode 35 5th electrode 36 6th electrode 43 First Through Hole 44 First phononic crystal layer 45 Second Through Hole 46 Second phononic crystal layer 50 Through hole 51A First Domain 51B Second Domain 52 Phononic polycrystalline structures 53A,53B Direction 55 Interface 56 Phononic crystal layer 61 Pillar 62 Oxide Film 91, 91A, 91B Unit Cell

Claims

1. A thermoelectric conversion device, An insulating layer; and a thermoelectric conversion module provided on the insulating layer, Where: The thermoelectric conversion module includes a first thermoelectric conversion region and a second thermoelectric conversion region, The first thermoelectric conversion region includes one or more thermoelectric conversion elements, a first connection electrode, and a second connection electrode, the thermoelectric conversion element in the first thermoelectric conversion region is electrically connected to the first connection electrode and the second connection electrode, and is located on an electrical path connecting the first connection electrode and the second connection electrode; The second thermoelectric conversion region includes one or more thermoelectric conversion elements, a third connection electrode, and a fourth connection electrode, the thermoelectric conversion element in the second thermoelectric conversion region is electrically connected to the third connection electrode and the fourth connection electrode, and is located on an electrical path connecting the third connection electrode and the fourth connection electrode; Each of the thermoelectric conversion elements includes a thermoelectric conversion portion, The thermoelectric conversion portion of at least one of the thermoelectric conversion elements includes a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes; a penetration direction of the plurality of through holes in the phononic crystal structure is approximately parallel to a direction perpendicular to a main surface of the insulating layer, the thermoelectric conversion portion of the at least one thermoelectric conversion element includes a first phononic crystal layer and a second phononic crystal layer that are the phononic crystal layer; The first phononic crystal layer has a first phononic crystal structure including a plurality of first through holes regularly arranged as the through holes, The second phononic crystal layer has a second phononic crystal structure including a plurality of second through holes regularly arranged as the through holes, The first phononic crystal layer and the second phononic crystal layer are stacked in a direction perpendicular to a main surface of the insulating layer.

2. The thermoelectric conversion device according to claim 1 , The first thermoelectric conversion region and / or the second thermoelectric conversion region includes two or more of the thermoelectric conversion elements.

3. The thermoelectric conversion device according to claim 1 , The thermoelectric conversion device satisfies the following (a) and / or (b). (a) the first thermoelectric conversion region includes two or more of the thermoelectric conversion elements; The two or more thermoelectric conversion elements in the first thermoelectric conversion region are connected to the first connection electrode and The two connection electrodes are electrically connected to each other in series. (b) the second thermoelectric conversion region includes two or more of the thermoelectric conversion elements; The two or more thermoelectric conversion elements in the second thermoelectric conversion region are connected to the third connection electrode and The electrodes are electrically connected in series with each other between the four connection electrodes.

4. The thermoelectric conversion device according to any one of claims 1 to 3, The thermoelectric conversion elements in the first thermoelectric conversion region and / or the second thermoelectric conversion region are the thermoelectric conversion unit being a p-type thermoelectric conversion unit and an n-type thermoelectric conversion unit; first electrode; A second electrode; and a third electrode; Where: one end of the p-type thermoelectric conversion unit and one end of the n-type thermoelectric conversion unit are electrically connected via the first electrode, The other end of the p-type thermoelectric conversion unit is electrically connected to the second electrode, The other end of the n-type thermoelectric conversion unit is electrically connected to the third electrode, one electrode selected from the second electrode and the third electrode is located on the electrical path and upstream of the path; The other electrode selected from the second electrode and the third electrode is located on the electrical path and downstream of the path.

5. The thermoelectric conversion device according to any one of claims 1 to 3, The thermoelectric conversion elements in the first thermoelectric conversion region and / or the second thermoelectric conversion region are the thermoelectric conversion unit being two p-type thermoelectric conversion units or two n-type thermoelectric conversion units adjacent to each other; Fourth electrode; A fifth electrode; and a sixth electrode; Where: one end of the one thermoelectric conversion unit and one end of the other thermoelectric conversion unit are electrically connected via the fourth electrode, the other end of the one thermoelectric conversion unit is electrically connected to the fifth electrode, the other end of the other thermoelectric conversion unit is electrically connected to the sixth electrode, one electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and upstream of the path; the other electrode selected from the fifth electrode and the sixth electrode is located on the electrical path and downstream of the path; When a current flows through the electrical path, the current flows in the same direction in the two adjacent thermoelectric conversion units.

6. The thermoelectric conversion device according to any one of claims 1 to 5, The first phononic crystal layer and the second phononic crystal layer are in contact with each other.

7. 7. The thermoelectric conversion device according to claim 1, At least a portion of the second through hole does not communicate with the first through hole.

8. The thermoelectric conversion device according to any one of claims 1 to 7, The phononic crystal structure includes a first domain and a second domain which are phononic crystal regions; the through holes in the first domain are regularly arranged in a first direction when viewed in a cross section perpendicular to a penetration direction of the through holes, The through holes in the second domain are regularly arranged in a second direction different from the first direction when viewed in a cross section perpendicular to the penetrating direction of the through holes.

9. The thermoelectric conversion device according to any one of claims 1 to 8, the phononic crystal layer comprises a plurality of pillars; The pillar is a columnar body extending linearly, Each of the pillars fills the through hole of the phononic crystal layer. However, when the phononic crystal layer in which the pillars are filled and the pillars are made of the same material, the periphery of the pillars is covered with an oxide film.

10. The thermoelectric conversion device according to any one of claims 1 to 9, A temperature sensing module is further included.

11. The thermoelectric conversion device according to any one of claims 1 to 10, The device further includes a control module that controls a voltage applied to the first thermoelectric conversion region and / or the second thermoelectric conversion region.

12. A method for controlling a thermoelectric conversion device, comprising: The thermoelectric converter according to any one of claims 1 to 11, A first voltage is applied to the first thermoelectric conversion region; applying a second voltage to the second thermoelectric conversion region; The first voltage and the second voltage have different application patterns.

13. 13. The control method according to claim 12, the thermoelectric conversion device includes a first temperature detection module; An application pattern of the first voltage and / or the second voltage is controlled based on information about the temperature acquired by the first temperature detection module.

14. 14. The control method according to claim 12 or 13, An object to be cooled and / or heated by the thermoelectric conversion device is placed near the thermoelectric conversion device.

15. 15. The control method of claim 14, The object includes a second temperature detection module, or a second temperature detection module is disposed between the object and the thermoelectric conversion device, An application pattern of the first voltage and / or the second voltage is controlled based on information about the temperature acquired by the second temperature detection module.

16. 16. A control method according to claim 14 or 15, comprising: The application pattern of the first voltage and / or the second voltage is controlled so that the voltage applied to a thermoelectric conversion region selected from the first thermoelectric conversion region and the second thermoelectric conversion region, which is closer to the object, changes more frequently than the voltage applied to a thermoelectric conversion region farther from the object.

17. A control method according to any one of claims 14 to 16, comprising the steps of: An application pattern of the first voltage and / or the second voltage is controlled so that a change in temperature of the object falls within a predetermined range.

18. 18. A control method according to any one of claims 14 to 17, comprising the steps of: The object is a heat source.

19. A method for cooling and / or heating an object using a thermoelectric conversion device, comprising: The thermoelectric conversion device is a thermoelectric conversion device according to any one of claims 1 to 11, The method includes applying a first voltage to the first thermoelectric conversion region and applying a second voltage to the second thermoelectric conversion region in the thermoelectric conversion device, The first voltage and the second voltage have different application patterns.

20. 1. An electronic device comprising: Integrated circuits; and a thermoelectric conversion device for cooling and / or heating the integrated circuit; The thermoelectric conversion device is a thermoelectric conversion device according to any one of claims 1 to 11.

21. A method for controlling a thermoelectric conversion device, comprising: The thermoelectric conversion device is An insulating layer; and a thermoelectric conversion module provided on the insulating layer, Where: The thermoelectric conversion module includes a first thermoelectric conversion region and a second thermoelectric conversion region, The first thermoelectric conversion region includes one or more thermoelectric conversion elements, a first connection electrode, and a second connection electrode, the thermoelectric conversion element in the first thermoelectric conversion region is electrically connected to the first connection electrode and the second connection electrode, and is located on an electrical path connecting the first connection electrode and the second connection electrode; The second thermoelectric conversion region includes one or more thermoelectric conversion elements, a third connection electrode, and a fourth connection electrode, the thermoelectric conversion element in the second thermoelectric conversion region is electrically connected to the third connection electrode and the fourth connection electrode, and is located on an electrical path connecting the third connection electrode and the fourth connection electrode; Each of the thermoelectric conversion elements includes a thermoelectric conversion portion, The thermoelectric conversion portion of at least one of the thermoelectric conversion elements includes a phononic crystal layer having a phononic crystal structure including a plurality of regularly arranged through holes; a penetration direction of the plurality of through holes in the phononic crystal structure is approximately parallel to a direction perpendicular to a main surface of the insulating layer, The control method includes: In the thermoelectric conversion device, A first voltage is applied to the first thermoelectric conversion region; applying a second voltage to the second thermoelectric conversion region; the first voltage and the second voltage have different application patterns; an object to be cooled and / or heated by the thermoelectric conversion device is placed near the thermoelectric conversion device; The application pattern of the first voltage and / or the second voltage is controlled so that the voltage applied to a thermoelectric conversion region selected from the first thermoelectric conversion region and the second thermoelectric conversion region, which is closer to the object, changes more frequently than the voltage applied to a thermoelectric conversion region farther from the object.

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