JP2010135619A - Thermoelectric conversion module and generator using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoelectric conversion module capable of achieving an increase in power generation quantity by achieving a large difference in temperature in an element, and to provide a generator using the thermoelectric conversion module. <P>SOLUTION: The thermoelectric conversion module 100 has a structure in which a substrate is provided on both outside surfaces of a thermoelectric conversion unit assembly 60 having a plurality of thermoelectric conversion units in which p-type thin film layers 11 and n-type thin film layers 12 are laminated via an electric insulating layer 13 and the thin film layers are electrically connected in a connection 14. In the module, the substrate 20 and 30 consist of low heat transmission parts 21, 31 for covering the surface of the assembly 60, and high heat transmission parts 22, 32 embedded in through-holes provided on the low heat transmission parts and having one end connected to the vicinity of the connections 14 of the p-type and n-type thin film layers and the other end exposed from the holes of the surfaces of the low heat transmission parts, respectively. The surfaces of the high heat transmission parts exposed from the low heat transmission parts are each connected to high heat transmission temperature contact parts 40, 50, respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermoelectric conversion module that converts heat into electricity using a temperature difference and a power generation device in which the thermoelectric conversion module is connected to a solar cell.

  As global warming has progressed and problems such as bad weather and rising seawater have become seriously serious, solar cells are not only important in Japan as an energy source that does not emit carbon dioxide, a greenhouse gas, It is also recognized in Europe and the United States, and its introduction into homes and offices has become popular. Seventy percent of the solar cells introduced are Si-based solar cells, most of which are crystalline (single crystal or polycrystalline).

During midsummer daytime, the solar energy falling on the earth is about 1000 W / m ² , and the average power generation amount under these optimum conditions of these solar cells is about 150 W / m ² . That is, the conversion efficiency is about 15%. However, in reality, it depends strongly on the latitude of the place where you live, the orientation of the house, the presence of obstacles, the difference in season, the weather, and the like, and the value of 15% is realized throughout the year. is not.

The average amount of power required in an average home will be about 4 kW, but if the average home wants to introduce solar cells, about 26 m ² will be required. Considering effective efficiency, about 40 m ² will be necessary. Securing such a roof area is not so easy. Therefore, in order to make the area as small as possible, a solar cell unit having a high conversion efficiency is required.

  Further, during the daytime of midsummer, the solar cell temperature is 80 ° C. or higher in the time zone where the amount of power generation is the largest for the solar cell. When the temperature of a crystalline silicon solar cell rises to 80 ° C., the conversion efficiency at room temperature falls by 20 to 30% (see FIG. 1). In order to compensate for the decrease in efficiency, the area of the solar cell placed on the roof has to be increased, which is not only expensive, but it is also difficult to secure the area on the roof. If the effective efficiency of the solar cell can be increased, the required solar cell area on the roof can be reduced, leading to cost reduction. For these reasons, an inexpensive solar cell with high power generation efficiency is desired.

  In the past, there was an idea to generate electricity by applying the thermoelectric conversion element on the back surface, taking advantage of the fact that the solar cell itself would be close to 80 ° C. around noon on a sunny day in midsummer (see Patent Documents 1 and 2). It has not been realized as a business. This is because, in order to generate as much power as possible, the conventional thermoelectric conversion element has a structure in which the space between the high temperature side and the low temperature side is as adiabatic as possible. Therefore, if the conventional thermoelectric conversion element is temporarily bonded to the solar cell, the temperature of the solar cell further increases, resulting in a decrease in the amount of power generated from the solar cell itself. The fact that it was thought that there was no point in assisting had a great influence.

  Furthermore, since it is difficult to produce a conventional thermoelectric conversion element, only an element with a small area can be produced. For this reason, the complexity of the process of adhering the element to the back of a large solar cell is also cited.

  There is also a situation that the thermoelectric conversion element is too expensive. This is a structure of a conventional thermoelectric conversion element using the Seebeck effect, and a structure in which a p-type and an n-type element are coupled in a “π” shape to stand vertically to a lower substrate. It is necessary to connect n-type-p-type in series, and the thermoelectric material generally used is Bi-Te, which is a brittle material and difficult to join with solder. For this reason, the reason is that it can only be made by hand.

  For this reason, it is not practical to use it on the back surface of a solar cell substrate, which is indispensable for a low price, and has not actually appeared in the market as a product.

  Under such a technical background, Patent Literature 3 and Non-Patent Literature 1 propose thermoelectric conversion elements that can generate power efficiently. That is, this thermoelectric conversion element is formed such that a thin film p-type thermoelectric conversion element made of a p-type material and a thin film n-type thermoelectric conversion element made of an n-type material are connected in series, and are formed on both sides thereof. A thermoelectric conversion unit is formed by forming electrodes, and a flexible film-like substrate composed of two types of materials having different thermal conductivities is provided on both sides of the thermoelectric conversion unit. On the unit side, a film is provided with a material such as polyimide resin, which is an insulator with low thermal conductivity, and on the side opposite to the joining surface of the thermoelectric conversion unit, a metal material such as copper with high thermal conductivity is in the form of the film. It is provided so that it may be located in a part of outer surface of a board | substrate.

  By adopting such a configuration, a temperature difference is generated inside the film substrate from the difference in heat flux of each layer when a temperature difference is applied to the upper and lower surfaces of the film substrate, and the thickness direction of the film substrate The temperature gradient is efficiently converted into a temperature gradient in the in-plane direction of the film-like substrate, and the temperature gradient is used to efficiently generate power with the thermoelectric conversion unit. The inventions described in Patent Document 3 and Non-Patent Document 1 have high mechanical strength, excellent workability, are easy to automate, can be mass-produced, and are flexible to curved surfaces. The object of the present invention is to provide a thermoelectric conversion element with high power generation efficiency that can be installed and is not limited in installation location.

  Specifically, using a mask, a p-type and n-type thermoelectric material is formed on the resin sheet by sputtering while controlling the element structure to form a thermoelectric conversion element portion, and the thermoelectric conversion element The thermoelectric conversion element is sandwiched by attaching another resin sheet on the part. Next, on both outer side surfaces of the bonded resin sheet and in a portion corresponding to the joint portion of the p-type and n-type thermoelectric conversion elements, a metal having good thermal conductivity such as copper is used to have the same size as the joint portion. Form an isomorphic pattern.

  Actually, a thermoelectric conversion element (FIG. 2) is formed on the back surface of a polyimide sheet (shown as material-A in FIG. 2) with copper (shown as material-B in FIG. 2) coated or pasted on one side. The other side of the polyimide sheet with no copper attached is bonded onto the thermoelectric conversion element, and the copper thin films on both surfaces of the bonded sheet are etched. To cut the desired pattern. A cross section of this structure is shown in FIG. This copper part comes into contact with the high temperature part and the low temperature part. Due to the heat conduction from there, there was a temperature difference in the thermoelectric conversion element parallel to the resin sheet surface, and power was generated.

  However, in this method, the heat conduction from the temperature contact portion on the high temperature side and the low temperature side (hereinafter referred to as the temperature contact portion) is only the heat conduction by thermal diffusion in the resin, and therefore the heat conductivity to the thermoelectric conversion element. However, since the temperature gradient is low and the temperature gradient in the thermoelectric conversion element is difficult to be attached, the problem is that the amount of power generation becomes small.

  On the other hand, in Non-Patent Documents 2 and 3, a p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material are laminated via an electrical insulating layer, and the p-type thin film layer and the n-type thin film layer are stacked. A thermoelectric conversion module having a structure in which a plurality of thermoelectric conversion units electrically connected on the end side of each thin film layer is laminated via an electric insulating layer in the thickness direction of the thin film layer has also been proposed.

However, the thermoelectric conversion modules proposed in Non-Patent Documents 2 and 3 are devised on the assumption that a temperature difference is created in the plane direction of each thin film layer, that is, in the horizontal plane. It is assumed that a temperature difference is created by bringing each end face of the thermoelectric conversion unit composed of the p-type thin film layer and the n-type thin film layer into contact with the temperature contact portions on the high temperature side and the low temperature side, respectively. A few thermoelectric conversion modules have the problem that they can only be used in a very limited arrangement.
JP 2001-53322 A JP 2003-69070 A JP 2006-186255 A NEDO 2006 Research Grants Project Results Report Industrial Technology Research Grants Project “Energy / Environmental Technology” Project ID: 03B70010c = Presentation of “Research and development of sheet-like flexible thermoelectric conversion elements for low-temperature waste heat utilization” “Low-dimensional thermoelectric materials” by MSDresselhaus Phys. Solid State 41, (1999) 679 R. Venkatasubramanian et al. “Aspects of thin film superlattice materials, devices, and applications” www.mrs.org/bulletin 31, (2006) 211

  The above-mentioned problems of the thermoelectric conversion elements proposed in Patent Document 3 and Non-Patent Document 1 have already been solved in the previous patent application (see Japanese Patent Application No. 2008-149062). Accordingly, the problem to be solved by the present invention is to solve the above-mentioned problems of the thermoelectric conversion module proposed in Non-Patent Documents 2 and 3 and available only in a very limited arrangement.

  Therefore, a p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material are laminated via an electrical insulating layer, and the p-type thin film layer and the n-type thin film layer are disposed on the end side of these thin film layers. The above-mentioned temperature difference is applied to a single thermoelectric conversion unit or a thermoelectric conversion unit stacked assembly in which one or more thermoelectric conversion units electrically connected in the connecting portion are stacked in the thickness direction of the thin film layer via an electric insulating layer. As a result of intensive studies by the inventor regarding the structure for forming the thermoelectric conversion unit, each end face of the thermoelectric conversion unit assumed in Non-Patent Documents 2 and 3 is replaced with a structure in which the temperature contact portions on the high temperature side and the low temperature side are brought into contact with each other. In addition, a substrate composed of a low thermal conductivity portion and a high thermal conductivity portion, which has been proven in Japanese Patent Application No. 2008-149062, is provided on both outermost surfaces of the thermoelectric conversion unit alone or the thermoelectric conversion unit laminated assembly. Even in the case of adopting, the temperature of the high temperature part and the low temperature part can be efficiently transmitted to the thermoelectric conversion unit (thermoelectric element part), and this has led to the finding that a large temperature difference is realized in the thermoelectric conversion module. . The present invention has been completed by such technical discovery.

That is, the invention according to claim 1
A p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material are laminated via an electrical insulating layer, and the p-type thin film layer and the n-type thin film layer are connected to the end portions of these thin film layers. The thermoelectric conversion units electrically connected to each other in the thickness direction of the thin film layer or a plurality of the thermoelectric conversion units laminated via the electric insulating layer are heated on both outermost surfaces of the thermoelectric conversion unit or the thermoelectric conversion unit laminated assembly. Assuming a thermoelectric conversion module in which substrates made of materials having different conductivities are provided, and one substrate side is disposed on the high temperature side and the other substrate side is disposed on the low temperature side,
Each of the substrates is made of a material having a low thermal conductivity and is composed of a low thermal conductivity portion covering the surface of the single unit of the thermoelectric conversion unit or the outermost surface of the laminated assembly, and a material having a high thermal conductivity and the low thermal conductivity. Embedded in a through-hole or recess provided along the thickness direction of the portion, and one end of the thermoelectric conversion unit is connected to or close to the vicinity of the connection portion, and the other end is a through-hole or recess in the surface of the low heat conducting portion. And the surface of the high thermal conductivity portion exposed from the through hole or recess of the surface of the low thermal conductivity portion is connected to a temperature contact portion composed of a material having high thermal conductivity. It is characterized by.

Next, the invention according to claim 2
Based on the thermoelectric conversion module according to the invention of claim 1,
The material with high thermal conductivity is metal,
The invention according to claim 3
Based on the thermoelectric conversion module according to any one of claims 1 and 2,
The temperature contact portion to which the surface of the high thermal conductivity portion of one substrate is connected is disposed on the high temperature side or the low temperature side, and the temperature contact portion on the other substrate is disposed in a state of being in thermal contact with the atmosphere side. ,
The invention according to claim 4
Based on the thermoelectric conversion module according to the invention of claim 3,
The thermal conductivity (κc) and the cross-sectional area (Sc) of the high thermal conductivity portion in the substrate, and the thermal conductivity (κa) and the cross-sectional area (Sa) of the low thermal conductivity portion in the substrate are:
1.2κa × Sa ≧ κc × Sc (Formula 1)
And having a relationship
0.8κa × Sa ≦ κc × Sc (Formula 2)
It has the relationship of these.

The invention according to claim 5
Based on the thermoelectric conversion module according to any one of claims 1 to 4,
The surface of the temperature contact portion is covered with a substantially black oxide film or a material having high thermal conductivity,
The invention according to claim 6
Based on the thermoelectric conversion module according to any one of claims 1 to 4,
The surface of the temperature contact portion of the substrate disposed on the low temperature side is roughened,
The invention according to claim 7 provides:
Based on the thermoelectric conversion module according to any one of claims 1 to 4,
A heat sink is added to the surface of the temperature contact portion of the substrate disposed on the low temperature side,
The invention according to claim 8 provides:
Assuming the thermoelectric conversion module according to any one of claims 1 to 7,
The material having low thermal conductivity in the substrate is resin or glass, and the thickness from the outermost surface of the thermoelectric conversion unit single-sided surface or the thermoelectric conversion unit laminated assembly to the substrate surface is 75 μm or more. It is what.

Next, the invention according to claim 9 is:
Assuming a power generator,
The thermoelectric conversion module according to any one of claims 1 to 8 is adhered to the back side of the solar cell, and the power is generated by a temperature difference between the solar cell and the outside air,
The invention according to claim 10 is:
On the premise of the power generation device according to the invention of claim 9,
When the thermal conductivity of the adhesive used for bonding the solar cell and the thermoelectric conversion module is (W / mK) and the thickness of the adhesive is (d), the ratio of (W / mK) / (d) is 1000 or more. It is characterized by
The invention according to claim 11 is:
On the premise of the power generation device according to the invention of claim 9,
The substrate surface on the surface side not contacting the solar cell in the thermoelectric conversion module is covered with each temperature contact portion connected to the high heat conduction portion exposed from the through hole or the concave portion of the surface of the low heat conduction portion. age,
The invention according to claim 12
On the premise of the power generation device according to the invention of claim 9,
The solar cell is an amorphous Si solar cell,
The invention according to claim 13 is:
On the premise of the power generation device according to the invention of claim 9,
When the temperature on the surface side in contact with the solar cell in the thermoelectric conversion module is lower than the temperature on the surface side not in contact with the solar cell, a switch that switches between positive and negative of electricity is provided in the circuit of the thermoelectric conversion module It is characterized by being.

According to the thermoelectric conversion module according to the present invention,
A p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material are laminated via an electrical insulating layer, and the p-type thin film layer and the n-type thin film layer are connected to the end portions of these thin film layers. The thermoelectric conversion units electrically connected to each other in the thickness direction of the thin film layer or a plurality of the thermoelectric conversion units laminated via the electric insulating layer are heated on both outermost surfaces of the thermoelectric conversion unit or the thermoelectric conversion unit laminated assembly. In the thermoelectric conversion module comprising substrates each made of a material having different conductivity, and one substrate side being disposed on the high temperature side and the other substrate side being disposed on the low temperature side.
Each of the substrates is made of a material having a low thermal conductivity and is composed of a low thermal conductivity portion covering the surface of the single unit of the thermoelectric conversion unit or the outermost surface of the laminated assembly, and a material having a high thermal conductivity and the low thermal conductivity. Embedded in a through-hole or recess provided along the thickness direction of the portion, and one end of the thermoelectric conversion unit is connected to or close to the vicinity of the connection portion, and the other end is a through-hole or recess in the surface of the low heat conducting portion. And a structure in which the surface of the high thermal conductivity portion exposed from the through-hole or the concave portion of the surface of the low thermal conductivity portion is connected to a temperature contact portion composed of a material having a high thermal conductivity. Have.

  For this reason, the temperature of the high temperature part and the low temperature part can be efficiently transmitted to the thermoelectric conversion unit (thermoelectric element part) through each temperature contact part and each substrate, thereby realizing a large temperature difference in the thermoelectric conversion module. As a result, the amount of power generation can be increased and improved.

  In addition, each end surface of the thermoelectric conversion unit assumed in Non-Patent Documents 2 and 3 is not a structure in which the end surface of the thermoelectric conversion unit is in contact with the temperature contact portion on the high temperature side or the low temperature side. Since the above-described substrate composed of the low thermal conductivity portion and the high thermal conductivity portion is provided on both outer surfaces, the degree of freedom of arrangement in the thermoelectric conversion module can be greatly improved.

  Furthermore, by adhering the thermoelectric conversion module according to the present invention to the back surface side of the solar cell, the power generation efficiency in the solar cell can be assisted, and the effective power generation efficiency of the solar cell can be increased.

  Hereinafter, embodiments of the present invention will be described in detail.

  First, in the thermoelectric conversion module 100 according to the present invention, as shown in FIG. 3, a p-type thin film layer 11 made of a p-type material and an n-type thin film layer 12 made of an n-type material are laminated via an electrical insulating layer 13 and The thermoelectric conversion unit 10 in which the p-type thin film layer 11 and the n-type thin film layer 12 are electrically connected at the connection portion 14 on the end side of the thin film layer is connected to the electric insulating layer 13 in the thickness direction of the thin film layer. The two substrates 20 and 30 made of materials having different thermal conductivities are provided on both outermost surfaces of the thermoelectric conversion unit laminate assembly 60 laminated through the two, respectively. A thermoelectric conversion module having a substrate side arranged on a low temperature side, wherein each of the substrates 20 and 30 is made of a material having low thermal conductivity and covers the outermost surface of the thermoelectric conversion unit laminate assembly 60. Conductive parts 21, 31 and It is made of a material having high thermal conductivity and is embedded in a through hole or a recess provided along the thickness direction of the low thermal conductivity portion, and one end thereof is provided in the vicinity of the connection portion 14 in the thermoelectric conversion unit 10. The other end side is connected to the thermal electrode parts 23 and 33 and the high heat conduction parts 22 and 32 exposed from the through holes or the recesses on the surface of the low heat conduction parts 21 and 31, and the surface of the low heat conduction parts 21 and 31 is penetrated. The surfaces of the high thermal conductivity portions 22 and 32 exposed from the holes or the recesses are connected to temperature contact portions 40 and 50 made of a material having high thermal conductivity.

And when the board | substrate side shown with the code | symbol 20 of the thermoelectric conversion module 100 which concerns on this invention is each arrange | positioned to the high temperature side, and the board | substrate side shown with the code | symbol 30 is each set to the low temperature side, the heat | fever (temperature) in the high temperature temperature contact part 40 is a board | substrate. 20 is transmitted to the thermoelectric conversion unit 10 (thermoelectric element portion) located on the upper side of the drawing through the high heat conduction portion 22 and the thermal electrode portion 23, and from the thermoelectric conversion unit 10 (thermoelectric element portion) located on the lower side of the drawing. Since the heat (temperature) is efficiently transmitted to the low temperature contact portion 50 through the hot electrode portion 33 and the high heat conduction portion 32 of the substrate 30, a large temperature difference can be realized in the thermoelectric conversion module 100.

1. Configuration of Thermoelectric Conversion Module (a) Thermoelectric Conversion Material As a thermoelectric conversion material, FeSi ₂ which has low thermoelectric properties but is abundant in resources other than chalcogen compounds such as IrSb ₃ , Bi ₂ Te ₃ and PbTe having high performance. And silicides such as SiGe. In addition, by adjusting the amount of various additive elements such as P, B, and Al alone or combined so that the carrier concentration in the Si semiconductor is about 10 ²⁴ (1 / m ³ ) and the amount added, the Seebeck coefficient can be increased. Si-based thermoelectric conversion materials that are extremely large and have significantly improved thermoelectric conversion efficiency can also be used. In addition, any known material can be used. In Si, at least one of Ge, C, and Sn is 5 to 10 atomic%, and at least one of additive elements for making Si a p-type semiconductor or an n-type semiconductor is 0.001 atomic% to 20 atomic%. And a Si-based thermoelectric having a crystal structure in which one or more of the above-described Ge, C, and Sn, or one or more additional elements for forming a p-type semiconductor or an n-type semiconductor are deposited at the grain boundary portion of polycrystalline Si. Si-based thermoelectric conversion materials such as conversion materials are preferable because of their extremely high thermoelectric conversion efficiency.
(B) Material with high thermal conductivity It is preferable that the material with high thermal conductivity that constitutes the high thermal conductivity part and the temperature contact part of the substrate is a metal or the like, specifically, copper, aluminum, or other thermal conductivity. Examples include high-grade metals, alloys, and ceramics. Moreover, about the high heat conductive part of the board | substrate arrange | positioned at a low temperature side and the board | substrate arrange | positioned at a high temperature side, both may be comprised with the same material, and may be comprised using a different material, and are arbitrary.
(C) Temperature contact part It is preferable that the surface of the said temperature contact part is coat | covered with the substantially black oxide film or the material with high heat conductivity. Examples of the above materials include copper oxides and resin materials with high thermal conductivity and high environmental resistance. This makes it easy to follow the temperature of the high temperature part and the low temperature part, and the temperature inside the thermoelectric conversion module. This is preferable because the gradient becomes large and large power generation is possible.

  Moreover, in the thermoelectric conversion module of this invention, it is preferable to roughen the surface of the said temperature contact part (low temperature side temperature contact part) of the board | substrate arrange | positioned at a low temperature side. In order to roughen the surface of the low temperature side temperature contact portion, it is only necessary to damage the surface with sandblasting or a file. For the surface roughness, the effective surface area is twice or more than the apparent area. The effect is great if it becomes rough so that the heat transfer coefficient becomes twice or more.

Moreover, in the thermoelectric conversion module of this invention, it is also possible to take the structure which added the heat sink to the surface of the low temperature side temperature contact part. By adopting such a configuration, it is possible to make the effective surface area more than twice the apparent surface area (simply seen from the dimensions), and obtain a large heat transfer coefficient (20 W / m ² K or more). Therefore, a large temperature difference between the high temperature part and the low temperature part is obtained, and the power generation amount is increased.

FIG. 4 is a graph showing a result of simulating the resin thickness dependence of the total power generation amount in a solar cell having a thermoelectric conversion module bonded to the back surface side. That is, when a thermoelectric conversion module to which a polyimide resin having a thermal conductivity of 0.2 W / mK is applied as a low thermal conductivity material constituting the low thermal conductivity portion is bonded to the back surface of the solar cell, the back surface temperature of the solar cell is set to 80. The graph shows the relationship between the resin thickness (μm) of the polyimide resin constituting the low heat conduction part and the total power generation amount in the solar cell when the atmospheric temperature is 30 ° C. The resin thickness is a distance from the surface of the thermoelectric conversion unit alone or its aggregate to the surface of the low thermal conductivity portion (substrate).
(D) Low thermal conductivity material Examples of the low thermal conductivity material constituting the low thermal conductivity portion of the substrate include resins such as polyimide and foamed polystyrene, or glass. When the thickness from the single surface of the thermoelectric conversion unit or the outermost surface of the thermoelectric conversion unit stacked assembly to the substrate surface is 75 μm or more, the power generation amount is 30 W / m ² or more realistic as shown in FIG. It turns out that it is preferable. If the thickness from the outermost surface of the single surface of the thermoelectric conversion unit or the thermoelectric conversion unit laminated assembly to the substrate surface is less than 75 μm, the actual desired value for supporting the power generation amount of the solar cell is reduced. There is a case. As an auxiliary to the solar cell, a power generation amount of 30 W / m ² or more is desired (corresponding to 3% in terms of power generation efficiency), and 75 μm or more is preferable to ensure this. It should be noted that the low thermal conductivity portions of the substrate disposed on the low temperature side and the substrate disposed on the high temperature side may both be composed of the same material or may be composed of different materials.

  Further, the material constituting the low thermal conductivity portion is an electrically insulating material, and is preferably a material having as low a thermal conductivity as possible. Depending on the purpose, a resin material such as polyimide and foamed polystyrene, or a glass material can be used properly. The low thermal conductivity part is desirably low in thermal conductivity, and the low thermal conductivity part is desirably thick because the temperature difference between thermoelectric conversion elements becomes large.

And when the conventional three-dimensional thermoelectric conversion element with high heat insulation is bonded to the back side of the solar cell, there is a risk that the temperature of the solar cell rises as described above, but the low heat conduction part by the resin of about 100 μm The thermal insulation is not a problem. In addition, when the low heat conduction part becomes too thick, the temperature rise of the solar cell itself may become a problem. However, when the low heat conduction part is several mm, the influence of the temperature rise is not so great.

2. Manufacture of Thermoelectric Conversion Module As described above, the thermoelectric conversion module according to the present invention includes a p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material laminated via an electric insulating layer, and the p-type A plurality of thermoelectric conversion units in which the thin film layer and the n-type thin film layer are electrically connected at the end of the thin film layer are laminated in the thickness direction of the thin film layer via a single or an electric insulating layer. The thermoelectric conversion unit alone or the thermoelectric conversion unit laminate assembly has a structure in which substrates each composed of a low thermal conductivity portion and a high thermal conductivity portion are provided on both outermost surfaces. And the thermoelectric conversion module which concerns on this invention can be manufactured as follows.

  For example, as shown in FIG. 6, three types of masks as shown in FIGS. 5A to 5C are appropriately replaced on one surface of a 500 μm thick polyimide resin sheet constituting a part of the substrate. A thermoelectric conversion unit laminate assembly is manufactured. That is, the polyimide resin sheet and the mask are arranged in a sputtering apparatus. First, on the polyimide resin sheet 13 using the mask shown in FIG. 5C having a wider opening width than the mask shown in FIGS. A p-type thin film layer 11 made of p-type material and having a thickness of about 1 nm is formed on the mask, and the opening width at the left end of the drawing is narrower than that of the mask shown in FIG. 5C. The electric insulating layer 13 having a thickness of about 10 nm is formed on the p-type thin film layer 11 by replacement, and the mask shown in FIG. 5C is replaced with an n-type material on the electric insulating layer 13. After the n-type thin film layer 12 having a thickness of about 1 nm is formed, the n-type thin film layer 12 is replaced with the mask shown in FIG. 5A having a narrow opening width at the right end of the drawing as compared with the mask shown in FIG. An electrical insulating layer 13 having a thickness of about 10 nm is formed on the thin film layer 12. Through these series of film forming processes, as shown in FIG. 6, the p-type thin film layer 11 and the n-type thin film layer 12 are connected to each other at the connection portion 14 at the left end of the drawing, and the thermoelectric conversion located at the lower side of the drawing. A unit 10 is formed.

  Next, by replacing the mask shown in FIG. 5C, a p-type thin film layer 11 made of p-type material and having a thickness of about 1 nm is formed on the electrical insulating layer 13, and FIG. An electric insulating layer 13 having a thickness of about 10 nm is formed on the p-type thin film layer 11 by replacing the mask shown in FIG. 5, and n is formed on the electric insulating layer 13 by replacing the mask shown in FIG. After forming an n-type thin film layer 12 made of a mold material and having a thickness of about 1 nm, the electric insulating layer 13 having a thickness of about 10 nm is formed on the n-type thin film layer 12 by replacing the mask shown in FIG. Form a film. By these series of film forming processes, the n-type thin film layer 12 and the p-type thin film layer 11 are connected to each other at the connecting portion 14 at the right end portion of the drawing as shown in FIG. 6, and the left end portion of the drawing as shown in FIG. The p-type thin film layer 11 and the n-type thin film layer 12 are connected to each other at the connecting portion 14, and the thermoelectric conversion unit 10 located on the upper side of the drawing is placed on the thermoelectric conversion unit 10 located on the lower side of the drawing via the electrical insulating layer 13. Are stacked, and a thermoelectric conversion unit stacked assembly 60 in which the pair of thermoelectric conversion units 10 are connected in series via the connection portions 14 is formed.

  Next, a polyimide resin sheet (not shown) having a thickness of about 50 μm was adhered on the electrical insulating layer 13 of the thermoelectric conversion unit 10 located on the upper side of the drawing, and the thermoelectric conversion unit laminate assembly 60 was sandwiched between the polyimide resin sheets. Thereafter, in the vicinity of the connecting portion 14 between the p-type thin film layer 11 and the n-type thin film layer 12, as shown in FIG. 7, the thermoelectric conversion unit 10 is electrically insulated but thermally connected well. A hot electrode portion (see reference numeral 23 in FIG. 3) 230 made of metal is formed with a paste or the like to a thickness of about several hundred microns. Further, on the opposite end of the thermoelectric conversion unit laminate assembly 60 from the portion where the hot electrode portion 230 is formed and on the end opposite to the position where the hot electrode portion is formed (see FIG. 3). 330) is formed by the same method, and a unit composed of a heat insulating material such as expanded polystyrene is polymerized on the pair of polyimide resin sheets, and a pair of substrates (see numerals 20 and 30 in FIG. 3). 200 and 300.

  Next, an excimer laser is irradiated for 12.5 seconds through a mask having a hole with a diameter of 0.5 mm toward a portion corresponding to the hot electrode portion 230 of one substrate 200 sandwiching the thermoelectric conversion unit stacked assembly 60. Then, after opening a through hole to a place where the diameter of the thermal electrode portion 230 can be seen about 0.5 mm in diameter, and adding an adhesive with good thermal conductivity in the through hole, as shown in FIG. A copper material having a high thermal conductivity having a diameter of 0.5 mm and a length of 0.5 mm is embedded (which constitutes the high thermal conductivity portion 70). Similarly, an excimer laser is irradiated for 12.5 seconds through the mask toward the portion corresponding to the hot electrode portion 330 of the other substrate 300, and the hot electrode portion 330 has a diameter of about 0.5 mm. Open the through hole until you can see it. Note that if irradiation is performed for a long time of 12.5 seconds or more, 10 parts of the thermoelectric conversion unit may be penetrated, but if stopped in 12.5 seconds, the 10 parts of the thermoelectric conversion unit may remain almost. It has been confirmed. Thereafter, an adhesive having thermal conductivity is applied to the surface of a copper material having a diameter of 0.5 mm, and is embedded in the through hole to obtain a high thermal conductive member 70. In addition, when the high heat conduction part 70 is comprised by embedding a copper material, the electrical connection between the high heat conduction part 70 and the thermoelectric conversion unit 10 part is not necessary, and there is no problem as long as the thermal connection can be obtained. Therefore, the through-hole in which the copper material is embedded may be constituted by a recess in which the thermoelectric conversion unit 10 part side is closed and the opposite surface side is opened. In addition, the p-type thin film layer and the n-type thin film layer are formed so that the end-side connection portion corresponds to a position where the one end side of the high heat conduction portion 70 is connected or close (formation portion of the thermal electrode portions 230 and 330). .

  Further, through a mask on which a film can be formed on the substrate 200 corresponding to the thermoelectric conversion unit 10, as shown in FIG. 7, a temperature contact portion on the high temperature side (for example, Cu is used and the film thickness is about 10 μm thick). ) 400 is formed by sputtering, and a low-temperature temperature contact portion (which may further contact the heat dissipation structure) 500 is also formed on the opposite substrate 300 to obtain the thermoelectric conversion module according to the present invention. It is done.

It should be noted that the contact size of the high thermal conductivity portion 70 whose one end side is in thermal contact with the vicinity of the connection portion between the p-type thin film layer and the n-type thin film layer in the thermoelectric conversion unit, and the temperature contact portions 300 and 400 on the high temperature side and the low temperature side. As shown in FIG. In particular, as shown in FIG. 3 and FIG. 7, it is preferable that the cross-sectional size of the temperature contact portion on the low temperature side (for example, the area of the temperature contact portion with the atmosphere) extends almost over the entire thermoelectric conversion unit. This is because the heat generation in the thermoelectric conversion unit (thermoelectric element portion) is larger when the heat radiation on the low temperature side is sufficiently performed. For example, the temperature contact part on the low temperature side may come into contact with the atmosphere for free heat dissipation. In this case, the heat radiation area as large as possible can efficiently dissipate heat, resulting in a large temperature difference between the high temperature part and the low temperature part. This leads to a large amount of power generation. In that sense, in the case of free heat radiation to the atmosphere, it is more effective to have a three-dimensional structure to increase the surface area, and to attach heat radiation fins, making it easier to add a temperature difference and increasing the amount of power generation.

3. Optimum conditions for “cross-sectional area of high thermal conductivity portion” and “cross-sectional area of low thermal conductivity portion” on the substrate As shown in FIG. In the thermoelectric conversion module according to the present invention, which is disposed on the side and disposed in a state where the temperature contact portion 80 on the other substrate is in thermal contact with the atmosphere side,
The heat flow condition that maximizes the power generation is
The thermal conductivity (κc) and the cross-sectional area (Sc) of the high thermal conductivity portion 81 in the substrate, and the thermal conductivity (κa) and the cross-sectional area (Sa) of the low thermal conductivity portion 82 in the substrate are:
1.2κa × Sa ≧ κc × Sc (Formula 1)
And having a relationship
0.8κa × Sa ≦ κc × Sc (Formula 2)
It is a case where it has the relationship of.

  Hereinafter, description will be made assuming that the heat flow in the thermoelectric conversion module (however, for the sake of simplicity, the thermoelectric conversion unit alone is assumed instead of the thermoelectric conversion unit aggregate) is the heat flow shown in FIG.

  Here, the meaning of each symbol is as follows.

S0: sectional area per thermoelectric conversion unit (thermoelectric element portion 83) = Sa + Sc
Sc: Cross-sectional area of high heat conduction part in substrate per thermoelectric conversion unit (thermoelectric element) Sa: Cross-sectional area of low heat conduction part in substrate per thermoelectric conversion unit (thermoelectric element) St: Thermoelectric conversion unit (thermoelectric element) ) Cross section per unit d: Thickness of “low thermal conduction part” L: Length of thermoelectric conversion unit (thermoelectric element) κc: Thermal conductivity of high thermal conduction part κa: Thermal conductivity of low thermal conduction material κt: Thermoelectric Thermal conductivity of conversion unit (thermoelectric element) α: Heat dissipation coefficient from T5 (atmosphere) Pf: Power factor of thermoelectric conversion unit (thermoelectric element) = S _B ² / (ρ _n + ρ _p )
ρ _n + ρ _p : Electric conductivity of n-type material and p-type material S _B : Seebeck coefficient Q 0: Energy irradiated from sunlight per thermoelectric conversion unit (thermoelectric element) (1000 W at 1 m ² ),
This is also
Q0 = α · S0 · (T5−T4): Equal to the energy released from the low temperature side surface.

  Here, the following relational expression is established between the heat flow (Q) shown in FIG. 8 and the above definition.

Q1 = κc × Sc × (T1-T2) × 2 / d
Q2 = κa × Sa × (T1−T4) / d
Q3 = κa × Sc × (T1−T3) × 2 / d
Q4 = κa × Sc × (T2−T4) × 2 / d
Q5 = κc × Sc × (T3−T4) × 2 / d
Q6 = κt × St × (T2−T3) / L
Further, the following relational expression is established between the heat flows from the relationship of continuous heat flow.

Q0 = Q1 + Q2 + Q3
Q1 = Q4 + Q6
Q5 = Q3 + Q6
When these three formulas obtained from the relationship of continuity of heat flow and the above four formulas of Q0 = α · S0 · (T5−T4) are combined, each temperature T1, T2, T3, T4, which are four variables, is automatically set. Can be obtained. However, T5 is an atmospheric temperature, for example, a fixed value such as 30 ° C.

  If the temperature difference (T2−T3) obtained from these relational expressions is used, the power generation amount of the thermoelectric conversion unit (thermoelectric element) can be obtained.

That is, the power generation amount Pw per thermoelectric conversion unit (thermoelectric element) is
Pw = Pf × (T2−T3) ² × St / L
What is necessary is just to obtain | require the conditions which become the maximum of.

  Qualitatively, in order to increase the temperature difference ΔT = | T2−T3 | that determines the amount of power generation, it is necessary to increase the temperature difference between the temperatures T1 and T4.

  For this purpose, it is important to reduce the thermal conductivity of the low thermal conductivity material part as much as possible, thicken the low thermal conductivity material part, and increase the thermal conductivity of the high thermal conductivity part thermally connected to the high temperature part and the low temperature part. is there.

  If the high heat conduction part is made thick, the temperature difference between T1 and T4 becomes small, and eventually the temperature difference between T2 and T3 becomes small. Further, when the cross-sectional area of the high heat conducting portion is reduced, the temperature difference between T1 and T4 increases, but the temperature difference between T2 and T3 decreases.

  For this reason, it turns out that the appropriate value which maximizes the electric power generation amount of a thermoelectric conversion module exists.

  As a result, it can be seen that the power generation amount Pw has the maximum value in the vicinity where the value of “κa × Sa” is substantially equal to the value of “κc × Sc”.

When the condition is obtained by setting a range where 80% or more of the maximum power generation amount is secured as a preferable range of power generation amount,
1.2κa × Sa ≧ κc × Sc (Formula 1)
When,
0.8κa × Sa ≦ κc × Sc (Formula 2)
Is required to be within a preferred range.

4). Power Generation Device The power generation device according to the present invention is characterized in that the thermoelectric conversion module is bonded to the back side of the solar cell and generates power with a temperature difference between the solar cell and the outside air temperature.

  With such a configuration, it is possible to generate power using the temperature difference between the back surface of the solar cell and the outside air temperature, thereby improving the decrease in power generation efficiency due to the temperature increase of the solar cell.

By the way, in the power generation device according to the present invention, the thermal conductivity of the adhesive used for bonding the solar cell and the thermoelectric conversion module and the thickness of the adhesive are related to the power generation efficiency, and the thermal conductivity of the adhesive is (W / mK), where the thickness of the adhesive is (d), the ratio of (W / mK) / (d) is preferably 1000 or more. The heat flowing through the resin, which is a low thermoelectric material of about 0.1 (W / mK), is about 0.1 / 10 ⁻³ = 100 when the thickness is about 1 mm. Since it should not become a thermal resistance at the bonding portion with the solar cell, the heat flow in the bonding portion is 10 times or more compared to the heat flow of the resin, that is, the ratio of (W / mK) / (d) is 1000 or more. Is desirable.

  Moreover, about the board | substrate surface of each thermoelectric conversion unit of the surface side which is not in contact with the solar cell in a thermoelectric conversion module, by each temperature contact part connected to the high heat conduction part exposed from the through-hole or recessed part of the surface of a low heat conduction part It is preferably coated.

  Here, the kind of solar cell to which the thermoelectric conversion module according to the present invention is bonded is not particularly limited, and examples thereof include amorphous Si solar cells. Amorphous Si solar cells have a larger solar absorption coefficient than crystalline Si solar cells, so the film thickness of Si is 1 μm or less. In addition, since amorphous Si can be formed on a resin, a flexible solar cell can be made. However, since the power generation efficiency is low, about 8% on average, the type mounted on the roof requires a large area to achieve 4 kW, and the range of use is limited even at a low price. However, unlike crystalline Si solar cells, amorphous Si solar cells have a feature that power generation efficiency does not decrease even when the temperature rises. Therefore, the type in which the thermoelectric conversion module according to the present invention sandwiched between substrates made of thick resin or the like is bonded to the back surface of the solar cell can realize more efficient power generation. Since any type of solar cell can be powered by the thermoelectric conversion module according to the present invention independently of the solar cell itself, the thermoelectric conversion module according to the present invention can be applied to any type of solar cell. Can be used.

  Next, in the power generation device according to the present invention, when the temperature of the surface side in contact with the solar cell in the thermoelectric conversion module is lower than the temperature of the surface side not in contact with the solar cell, the positive / negative of electricity is determined. It is preferable that the switch to switch is provided in the circuit of the thermoelectric conversion module. The reason for providing the switch is that the temperature on the surface side in contact with the solar cell is not necessarily a high temperature part, and depending on the outside air temperature or the way of installing the solar cell, it becomes a low temperature part and may generate a reverse voltage. Because there is. In this case, if the structure is switched between positive and negative with a switch, power generation is possible even at night without the sun. Therefore, it is preferable to provide a switch in the circuit that can automatically switch between positive and negative. In the present specification, unless otherwise specified, the bonding portion side with the back surface of the solar cell is described as a high temperature portion.

  Examples of the present invention will be specifically described below, but the present invention is not limited to the following examples.

As shown in FIG. 9, a hot electrode part having a thickness of 50 μm is formed on one surface of a polyimide resin sheet 130 having a thickness of 500 μm constituting a part of the substrate using a conductive paste (manufactured by Mitsubishi Materials Corporation: silver nanopaste). After forming 133, an n-type material (Bi _{2) is formed} by sputtering film formation while appropriately replacing the three types of masks shown in FIGS. 5A to 5C on the other surface of the polyimide resin sheet 130. A 1 nm thick n-type thin film layer 12 made of Te ₃ ), a 10 nm thick electrically insulating layer 13 made of an electrically insulating material (SrTiO ₃ ), and a 1 nm thick made of a p-type material [(BiSb) ₂ Te ₃ ]. The p-type thin film layer 11 and an electrically insulating layer 13 made of the same material and having a thickness of 10 nm are formed to form the thermoelectric conversion unit 10. Thereafter, a total of 100 sets are formed on the thermoelectric conversion unit 10 by the same method. However, after the three thermoelectric conversion units are stacked and the electrical insulating layer 13 is formed, the other thermal electrode portion 123 is disposed at a position opposite to the thermal electrode portion 133. And the thermoelectric conversion unit laminated assembly 60 connected in series with each other was manufactured. Here, ten thermoelectric conversion unit stacked assemblies 60 are arranged in a plane (however, two are illustrated in FIG. 9). Further, the entire size of the thermoelectric conversion unit alone is about 30 mm × 65 mm, and the ten thermoelectric conversion unit stacked assemblies 60 are electrically connected in parallel as shown in FIG. The parts 123 and 133 are arranged so as to straddle the adjacent thermoelectric conversion unit stacked assemblies 60. In FIG. 9, the numerical value with the unit “mm” indicates the design dimension of the thermoelectric conversion unit stacked assembly 60.

  Next, with respect to the ten thermoelectric conversion unit laminated assemblies 60 on which the hot electrode portions 123 and 133 are formed, a 2 mm thick polystyrene foam (see reference numerals 20 and 30 in FIG. 3) is arranged on the outermost surface, and the above High heat conduction parts made of copper having a diameter of 0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm from the upper and lower portions of the parts corresponding to the respective thermal electrode parts 123 and 133 of the polystyrene foam (length 2 mm) ) Was inserted by an excimer laser, and an adhesive was applied to the surface of the copper wire to be a high heat conduction portion and inserted into the through hole.

  The excimer laser irradiation conditions are as follows.

Excimer laser: Exitech excimer laser processing machine PS2000
Wavelength used: 248 (nm)
Optical system used: 10x lens Transmission frequency = 100 Hz
Next, with respect to the thermoelectric conversion module precursor in which the copper wire constituting the high heat conduction part is inserted into the through hole, the thickness constituting the temperature contact part (see reference numerals 40 and 50 in FIG. 3) of the high temperature part and the low temperature part. A 0.2 mm copper plate was bonded from both sides of the thermoelectric conversion module precursor, and the four types of thermoelectric conversion modules according to the examples (that is, the diameters were 0.2 mm, 0.4 mm, 0.6 mm, and 0.8 mm). A module in which a high thermal conductivity portion is formed of a certain copper wire is manufactured.

  Then, the power generation amount was measured in a state where the high temperature part side of the thermoelectric conversion module was bonded to a copper block at 80 ° C. and the other side of the thermoelectric conversion module was freely radiated to the atmosphere (25 ° C.). In addition, since the amount of power generation was changed when trying to measure the temperature difference in the thermoelectric conversion module, the temperature difference at the temperature contact portion between the upper and lower sides (that is, the high temperature portion and the low temperature portion) was measured. The results are shown in Table 1.

As shown in Table 1, the maximum power generation amount ( ² mW / cm ² ) was obtained in the case of a thermoelectric conversion module in which a high thermal conductivity portion was configured with a copper wire having a diameter of 0.4 mm.

In this case, it can be confirmed that the condition is substantially satisfied when “κa × Sa = κc × Sc” is satisfied. Here, κa = 0.1 W / mK, Sa = 10 × 30 mm ² , and κc = 200 W / mK.

  According to the thermoelectric conversion module according to the present invention, since a large temperature difference is realized in the thermoelectric conversion module, it is possible to increase and improve the amount of power generation, and is proposed in Non-Patent Documents 2 and 3. Compared to the thermoelectric conversion module, it is possible to greatly improve the degree of freedom of arrangement, and it is possible to increase the effective power generation efficiency of the solar cell by bonding it to the back side of the solar cell. Therefore, the thermoelectric conversion module according to the present invention has industrial applicability to be used by being incorporated in a solar cell.

The graph which shows the temperature characteristic of the conventional crystalline Si type solar cell. Sectional drawing which shows the principal part structure of the thermoelectric conversion element which concerns on a prior art. The schematic perspective view of the thermoelectric conversion module which concerns on this invention. The graph which shows the result of having simulated the resin thickness dependence of the total electric power generation amount of the solar cell by which the thermoelectric conversion module was adhere | attached on the back side. 5A to 5C are plan views showing an example of a mask used when manufacturing the thermoelectric conversion module according to the present invention. The schematic perspective view of the thermoelectric conversion unit laminated assembly in the middle of manufacture of the thermoelectric conversion module which concerns on this invention. The schematic perspective view of the thermoelectric conversion module which concerns on this invention which abbreviate | omitted the structure of the said thermoelectric conversion unit laminated assembly. The schematic of the heat flow in the thermoelectric conversion module which concerns on this invention. The schematic perspective view of the thermoelectric conversion unit lamination | stacking assembly | assembly in the middle of manufacture of the thermoelectric conversion module which concerns on the Example of this invention, and a thermal electrode part.

Explanation of symbols

10 thermoelectric conversion unit 11 p-type thin film layer 12 n-type thin film layer 13 electrical insulating layer (polyimide resin sheet)
DESCRIPTION OF SYMBOLS 14 Connection part 20 Board | substrate 21 Low thermal conduction part 22 High thermal conduction part 23 Thermal electrode part 31 Low thermal conduction part 32 High thermal conduction part 33 Thermal electrode part 40 Temperature contact part 50 Temperature contact part 60 Thermoelectric conversion unit laminated assembly 70 High thermal conduction part 80 Temperature Contact part 81 High heat conduction part 82 Low heat conduction part 83 Thermoelectric conversion unit (thermoelectric element part)
DESCRIPTION OF SYMBOLS 100 Thermoelectric conversion module 123 Thermal electrode part 130 Polyimide resin sheet 133 Thermal electrode part 200 Substrate 230 Thermal electrode part 300 Substrate 330 Thermal electrode part 400 Temperature contact part 500 Temperature contact part

Claims (13)

A p-type thin film layer made of a p-type material and an n-type thin film layer made of an n-type material are laminated via an electrical insulating layer, and the p-type thin film layer and the n-type thin film layer are connected at the end of the thin film layer. Conductive heat transfer is performed on the outermost surfaces of a single thermoelectric conversion unit or a thermoelectric conversion unit stacked assembly in which one or more thermoelectric conversion units that are electrically connected are stacked in the thickness direction of the thin film layer via an electric insulating layer. In a thermoelectric conversion module comprising substrates each made of a material having a different rate, wherein one substrate side is disposed on the high temperature side and the other substrate side is disposed on the low temperature side.
Each of the substrates is made of a material having a low thermal conductivity and is composed of a low thermal conductivity portion covering the surface of the single unit of the thermoelectric conversion unit or the outermost surface of the laminated assembly, and a material having a high thermal conductivity and the low thermal conductivity. Embedded in a through-hole or recess provided along the thickness direction of the portion, and one end of the thermoelectric conversion unit is connected to or close to the vicinity of the connection portion, and the other end is a through-hole or recess in the surface of the low heat conducting portion. And the surface of the high thermal conductivity portion exposed from the through hole or recess of the surface of the low thermal conductivity portion is connected to a temperature contact portion composed of a material having high thermal conductivity. A thermoelectric conversion module.   The thermoelectric conversion module according to claim 1, wherein the material having a high thermal conductivity is a metal.   The temperature contact portion to which the surface of the high thermal conductivity portion of one substrate is connected is disposed on the high temperature side or the low temperature side, and the temperature contact portion on the other substrate is disposed in a state of being in thermal contact with the atmosphere side. The thermoelectric conversion module according to claim 1. The thermal conductivity (κc) and the cross-sectional area (Sc) of the high thermal conductivity portion in the substrate, and the thermal conductivity (κa) and the cross-sectional area (Sa) of the low thermal conductivity portion in the substrate are:
1.2κa × Sa ≧ κc × Sc (Formula 1)
And having a relationship
0.8κa × Sa ≦ κc × Sc (Formula 2)
The thermoelectric conversion module according to claim 3, wherein:   The thermoelectric conversion module according to claim 1, wherein the surface of the temperature contact portion is covered with a substantially black oxide film or a material having high thermal conductivity.   The surface of the said temperature contact part of the board | substrate arrange | positioned at a low temperature side is roughened, The thermoelectric conversion module in any one of Claims 1-4 characterized by the above-mentioned.   The thermoelectric conversion module according to claim 1, wherein a heat radiating plate is added to the surface of the temperature contact portion of the substrate disposed on the low temperature side.   The material having low thermal conductivity in the substrate is resin or glass, and the thickness from the outermost surface of the thermoelectric conversion unit single-sided surface or the thermoelectric conversion unit laminated assembly to the substrate surface is 75 μm or more. The thermoelectric conversion module according to claim 1.   A thermoelectric conversion module according to any one of claims 1 to 8 is adhered to a back surface side of a solar cell, and a power generation device is configured to generate power with a temperature difference between the solar cell and outside air.   When the thermal conductivity of the adhesive used for bonding the solar cell and the thermoelectric conversion module is (W / mK) and the thickness of the adhesive is (d), the ratio of (W / mK) / (d) is 1000 or more. The power generator according to claim 9, wherein the power generator is provided.   The substrate surface on the surface side not contacting the solar cell in the thermoelectric conversion module is covered with each temperature contact portion connected to the high heat conduction portion exposed from the through hole or the concave portion of the surface of the low heat conduction portion. The power generator according to claim 9.   The said solar cell is an amorphous Si solar cell, The electric power generating apparatus of Claim 9 characterized by the above-mentioned.   When the temperature on the surface side in contact with the solar cell in the thermoelectric conversion module is lower than the temperature on the surface side not in contact with the solar cell, a switch that switches between positive and negative of electricity is provided in the circuit of the thermoelectric conversion module The power generator according to claim 9, wherein the power generator is provided.

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