WO2023038107A1 - Power generation element, method for manufacturing power generation element, power generation device, and electronic apparatus - Google Patents

Abstract

[Problem] To provide a power generation element, a method for manufacturing a power generation element, a power generation device, and an electronic apparatus with which it is possible to mitigate a decrease in the amount of power generated. [Solution] A power generation element 1 that does not require a temperature difference between electrodes during conversion of thermal energy into electric energy is characterized by comprising a first electrode 11, an intermediate portion 14 disposed on the first electrode 11 and including fine particles, and a second electrode 12 provided on the intermediate portion 14 and having a work function different from that of the first electrode 11. The fine particles include first fine particles and second fine particles having a central diameter smaller than that of the first fine particles. For example, the power generation element 1 is characterized in that the first fine particles have a particle number concentration less than a particle number concentration of the second fine particles.

Description

Power generation element, method for manufacturing power generation element, power generation device, and electronic device

The present invention relates to a method for manufacturing a power generation element, a power generation element, a power generation device, and an electronic device that eliminate the need for a temperature difference between electrodes when converting thermal energy into electrical energy.

In recent years, the development of power generation elements that generate electrical energy using thermal energy has been actively carried out. In particular, regarding a power generation element that does not require a temperature difference between electrodes, for example, a power generation element disclosed in Patent Document 1 has been proposed. Such a power generating element is expected to be used in various applications as compared with a configuration in which electric energy is generated by utilizing a temperature difference between electrodes.

Patent Document 1 discloses a generation step of generating nanoparticles dispersed in a solvent or an organic solvent using a femtosecond pulse laser, a first electrode portion forming step of forming a first electrode portion on a first substrate, a second electrode portion forming step of forming a second electrode portion on a second substrate; and the first substrate with the solvent or the organic solvent sandwiched between the first electrode portion and the second electrode portion. and a bonding step of bonding the second substrate and the like.

Japanese Patent No. 6781437

Here, in the power generation element disclosed in Patent Document 1, there is a concern that the amount of power generated may decrease due to fluctuations in the dispersion state of the nanoparticles between the electrodes. For this reason, it is desired to suppress the decrease in power generation due to fluctuations in fine particles such as nanoparticles.

Accordingly, the present invention has been devised in view of the above-described problems, and aims to provide a power generation element capable of suppressing a decrease in the amount of power generated, a method for manufacturing the power generation element, a power generation device, and to provide an electronic device.

A power generation element according to a first aspect of the invention is a power generation element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy, comprising: a first electrode; and a second electrode provided on the intermediate portion and having a work function different from that of the first electrode, the fine particles being smaller than the first fine particles and the first fine particles It is characterized by including second fine particles having a median diameter.

The power generation element according to the second invention is characterized in that, in the first invention, the particle number concentration of the first fine particles is lower than the particle number concentration of the second fine particles.

A power generating element according to a third invention is characterized in that, in the first invention or the second invention, the intermediate portion includes a non-conductor layer that encloses the fine particles and supports the first electrode and the second electrode. do.

A method for manufacturing a power generation element according to a fourth aspect of the invention is a method for manufacturing a power generation element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy, comprising: a first electrode; an intermediate portion containing fine particles; and a second electrode having a work function different from that of the first electrode, wherein the fine particles include first fine particles and second fine particles having a median diameter smaller than that of the first fine particles. characterized by comprising

A power generating device according to a fifth aspect of the invention includes the power generating element according to the first aspect of the invention, a first wiring electrically connected to the first electrode, and a second wiring electrically connected to the second electrode. It is characterized by having

An electronic device according to a sixth invention is characterized by comprising the power generating element according to the first invention and an electronic component driven by using the power generating element as a power supply.

According to the first to fourth inventions, the fine particles include the first fine particles and the second fine particles having a smaller median diameter than the first fine particles. Therefore, it is possible to increase the possibility that the second fine particles enter between the particles of the first fine particles, and it is possible to suppress fluctuations in the dispersed state of the fine particles. As a result, it is possible to suppress a decrease in the power generation amount.

In particular, according to the second invention, the particle number concentration of the first fine particles is lower than the particle number concentration of the second fine particles. That is, it is possible to increase the filling degree of the fine particles between the electrodes. Therefore, it is possible to further suppress fluctuations in the dispersed state of the fine particles. As a result, it is possible to further suppress the decrease in the power generation amount.

In particular, according to the third invention, the intermediate portion includes a non-conductor layer containing fine particles. That is, the non-conductor layer suppresses movement of the fine particles between the electrodes. For this reason, it is possible to prevent the fine particles from becoming unevenly distributed on one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Also, according to the third invention, the intermediate portion includes a non-conductor layer that supports the first electrode and the second electrode. Therefore, compared to the case where a solvent or the like is used instead of the non-conductive layer, there is no need to provide a support portion or the like for maintaining the distance (gap) between the electrodes, and the gap resulting from the formation accuracy of the support portion is eliminated. Distortion can be removed. This makes it possible to increase the amount of power generation.

In particular, according to the fifth invention, the power generator includes the power generation element according to the first invention. Therefore, it is possible to realize a power generation device that stabilizes the power generation amount.

In particular, according to the sixth invention, an electronic device includes the power generation element according to the first invention. Therefore, it is possible to realize an electronic device that stabilizes the amount of power generation.

FIG. 1(a) is a schematic cross-sectional view showing an example of a power generation element and a power generation device in an embodiment, and FIG. 1(b) is a schematic cross-sectional view along AA in FIG. 1(a). . FIG. 2 is a schematic cross-sectional view showing an example of the intermediate portion. FIG. 3(a) is a graph showing an example of particle size distribution of fine particles, and FIG. 3(b) is a graph showing an example of fine particles. FIG. 4 is a flow chart showing an example of a method for manufacturing a power generation element according to the embodiment. 5(a) to 5(d) are schematic cross-sectional views showing an example of the method for manufacturing the power generation element according to the embodiment. FIG. 6A is a schematic cross-sectional view showing a first modification of the power generation element and the power generation device in the embodiment, and FIG. 6B is a second modification of the power generation element and the power generation device in the embodiment. It is a schematic cross-sectional view showing the. FIG. 7 is a schematic cross-sectional view showing a first modification of the intermediate portion. FIG. 8 is a schematic cross-sectional view showing a second modification of the intermediate portion. FIGS. 9(a) to 9(d) are schematic block diagrams showing examples of electronic devices having power generation elements, and FIGS. 9(e) to 9(h) show power generation devices including power generation elements. It is a schematic block diagram which shows the example of the electronic device provided.

Hereinafter, examples of a method for manufacturing a power generation element, a power generation element, a power generation device, and an electronic device as embodiments of the present invention will be described with reference to the drawings. In each figure, the height direction in which each electrode is stacked is defined as a first direction Z, and one planar direction that intersects, for example, is orthogonal to the first direction Z is defined as a second direction X. A third direction Y is another planar direction that intersects, for example, is orthogonal to each of the directions X. As shown in FIG. Also, the configuration in each drawing is schematically described for explanation, and for example, the size of each configuration and the comparison of the size of each configuration may differ from those in the drawings.

(Embodiment: power generation element 1, power generation device 100)
FIG. 1 is a schematic diagram showing an example of a power generation element 1 and a power generation device 100 in this embodiment. FIG. 1(a) is a schematic cross-sectional view showing an example of a power generation element 1 and a power generation device 100 in this embodiment, and FIG. 1(b) is a schematic cross section along AA in FIG. 1(a). It is a diagram.

(Power generator 100)
As shown in FIG. 1( a ), the power generation device 100 includes a power generation element 1 , first wiring 101 and second wiring 102 . The power generation element 1 converts thermal energy into electrical energy. For example, the power generation device 100 including such a power generation element 1 is mounted or installed on a heat source (not shown), and based on the thermal energy of the heat source, the electrical energy generated from the power generation element 1 is transferred to the first wiring 101 and the second wiring 101. 2 output to the load R via the wiring 102 . One end of the load R is electrically connected to the first wiring 101 and the other end is electrically connected to the second wiring 102 . A load R indicates, for example, an electrical device. The load R is driven, for example, using the generator 100 as a main power source or an auxiliary power source.

Examples of heat sources for the power generation element 1 include electronic devices or electronic parts such as CPUs (Central Processing Units), light emitting elements such as LEDs (Light Emitting Diodes), engines such as automobiles, production equipment in factories, human bodies, sunlight, and environmental temperature. For example, electronic devices, electronic parts, light-emitting elements, engines, production equipment, etc. are artificial heat sources. The human body, sunlight, ambient temperature, etc. are natural heat sources. The power generation device 100 including the power generation element 1 can be provided inside mobile devices such as IoT (Internet of Things) devices and wearable devices and self-supporting sensor terminals, and can be used as an alternative or supplement to batteries. Furthermore, the power generation device 100 can also be applied to larger power generation devices such as solar power generation.

(Power generation element 1)
The power generation element 1 converts, for example, thermal energy generated by the artificial heat source or thermal energy possessed by the natural heat source into electrical energy to generate current. The power generation element 1 can be provided not only inside the power generation device 100, but also inside the mobile device, the self-contained sensor terminal, or the like. In this case, the power generation element 1 itself can serve as an alternative or auxiliary part of the battery, such as the mobile device or the self-contained sensor terminal.

The power generation element 1 includes, for example, a first electrode 11, a second electrode 12, and an intermediate portion 14, as shown in FIG. 1(a). The power generation element 1 may include at least one of the first substrate 15 and the second substrate 16, for example.

The first electrode 11 and the second electrode 12 are provided facing each other. The first electrode 11 and the second electrode 12 have different work functions. The intermediate portion 14 is provided in a space 140 including a gap G between the first electrode 11 and the second electrode 12, as shown in FIG. 2, for example. The intermediate portion 14 includes fine particles 141 .

The particles 141 include first particles 141f and second particles 141s. For example, as shown in FIG. 3A, the median diameter D50s of the second fine particles 141s is smaller than the median diameter D50f of the first fine particles 141f. In this case, for example, as shown in FIG. 3B, it is possible to increase the possibility that the second fine particles 141s enter between the first fine particles 141f. At this time, compared to the case where only one of the fine particles 141f and 141s is included in the intermediate portion 14, the variable range is narrower. Therefore, fluctuation of the fine particles 141 can be suppressed. As a result, it is possible to suppress a decrease in the power generation amount.

In addition, since the particles 141 contain the particles 141f and 141s, the areas of the electrodes 11 and 12 in contact with the particles 141 can be increased compared to the case where only the first particles 141f having a large median diameter D50f are included. can. Therefore, the amount of electrons moving between the electrodes 11 and 12 can be increased. This makes it possible to increase the amount of power generation.

In addition, since the fine particles 141 include the fine particles 141f and 141s, the filling degree of the fine particles 141 in the intermediate portion 14 can be easily improved compared to the case where only the second fine particles 141s having a small median diameter D50s are included. can be done. Thereby, the movement of electrons between the fine particles 141 can be facilitated. Also in this respect, it is possible to improve the power generation amount.

The details of each configuration are described below.

<First Electrode 11, Second Electrode 12>
The first electrode 11 and the second electrode 12 are spaced apart in the first direction Z, as shown in FIG. 1(a), for example. Each of the electrodes 11 and 12 may extend in the second direction X and the third direction Y, for example, and may be provided in plurality. For example, one second electrode 12 may be provided facing the plurality of first electrodes 11 at different positions. Also, for example, one first electrode 11 may be provided facing the plurality of second electrodes 12 at different positions.

A conductive material is used as the material of the first electrode 11 and the second electrode 12 . As materials for the first electrode 11 and the second electrode 12, for example, materials having different work functions are used. The same material may be used for the electrodes 11 and 12, and in this case, the electrodes 11 and 12 may have different work functions.

As the material of the electrodes 11 and 12, for example, a material composed of a single element such as iron, aluminum, or copper may be used, or an alloy material composed of, for example, two or more elements may be used. A non-metallic conductor, for example, may be used as the material of the electrodes 11 and 12 . Examples of nonmetallic conductors include silicon (Si: for example, p-type Si or n-type Si) and carbon-based materials such as graphene.

The thickness of the first electrode 11 and the second electrode 12 along the first direction Z is, for example, 4 nm or more and 1 μm or less. The thickness of the first electrode 11 and the second electrode 12 along the first direction Z may be, for example, 4 nm or more and 50 nm or less.

The gap G, which indicates the distance between the first electrode 11 and the second electrode 12, can be arbitrarily set by changing the thickness of the non-conductor layer 142, for example. For example, by narrowing the gap G, the electric field generated between the electrodes 11 and 12 can be increased, so that the power generation amount of the power generation element 1 can be increased. Further, for example, by narrowing the gap G, the thickness of the power generation element 1 along the first direction Z can be reduced.

The gap G is a finite value of 500 μm or less, for example. The gap G is, for example, 10 nm or more and 1 μm or less. For example, if the gap G is 200 nm or less, variations in the gap G on the surfaces along the second direction X and the third direction Y may lead to a decrease in the power generation amount. Also, if the gap G is larger than 1 μm, the electric field generated between the electrodes 11 and 12 may weaken. For these reasons, the gap G is preferably larger than 200 nm and 1 μm or less.

<Intermediate part 14>
The intermediate portion 14 includes, for example, fine particles 141 and a non-conductor layer 142 . The non-conductor layer 142 contains the fine particles 141 and supports the first electrode 11 and the second electrode 12 . In this case, movement of the particles 141 in the gap G is suppressed by the non-conductor layer 142 . Therefore, it is possible to prevent the fine particles 141 from becoming unevenly distributed on the side of one of the electrodes 11 and 12 over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

The non-conductor layer 142 is formed, for example, by curing a non-conductor material. The non-conductor layer 142 exhibits a solid, for example. The non-conducting layer 142 may include, for example, diluent residue and uncured portions of the non-conducting material. In this case as well, it is possible to stabilize the power generation amount in the same manner as described above. Also, the fine particles 141 are fixed in a dispersed state in the non-conductor layer 142, for example. In this case as well, it is possible to stabilize the power generation amount in the same manner as described above.

The intermediate portion 14 is provided on the first electrode 11 . Also, the second electrode 12 is provided on the non-conductor layer 142 . Here, in the power generation element 1 that does not require a temperature difference between the electrodes when converting thermal energy into electrical energy, by suppressing variations in the gap G on the surfaces along the second direction X and the third direction Y, , the amount of power generation can be increased. In this regard, when a liquid such as a solvent is used as the intermediate portion, it is necessary to provide a support portion or the like for maintaining the gap G. However, there has been a concern that the gap G may vary greatly with the formation of the supporting portion and the like. On the other hand, in the power generating element 1 of the present embodiment, the second electrode 12 is provided on the non-conductor layer 142, so there is no need to provide a supporting portion or the like for maintaining the gap G, and the supporting portion or the like is not required. It is possible to eliminate gap variations due to formation accuracy. This makes it possible to increase the amount of power generation.

Also, when providing a support or the like for maintaining the gap, there is a concern that the fine particles 141 may come into contact with the support and aggregate around the support. On the other hand, in the power generating element 1 of the present embodiment, it is possible to eliminate the state in which the fine particles 141 aggregate due to the supporting portion. This makes it possible to maintain a stable power generation amount.

The intermediate portion 14 extends on a plane along the second direction X and the third direction Y, as shown in FIG. 1(b), for example. The intermediate portion 14 is provided within a space 140 formed between the electrodes 11 , 12 . The intermediate portion 14 may be in contact with the main surfaces of the electrodes 11 and 12 facing each other, and may also be in contact with the side surfaces of the electrodes 11 and 12, for example.

The fine particles 141 may be dispersed in the non-conductor layer 142 and partially exposed from the non-conductor layer 142, for example. The particles 141 may be filled in the gap G, for example, and the non-conductor layer 142 may be provided in the gaps between the particles 141 . The particle diameter of the fine particles 141 is smaller than the gap G, for example. The particle diameter of the fine particles 141 is set to a finite value of 1/10 or less of the gap G, for example. If the particle diameter of the fine particles 141 is set to 1/10 or less of the gap G, it becomes easier to form the intermediate portion 14 containing the fine particles 141 in the space 140 . This makes it possible to improve the workability when generating the power generation element 1 .

Here, "fine particles" refer to those containing a plurality of particles. The fine particles 141 include particles having a particle diameter of, for example, 2 nm or more and 1000 nm or less. The fine particles 141 may include, for example, particles having a median diameter (median diameter: D50) of 3 nm or more and 8 nm or less, or particles having an average particle diameter of 3 nm or more and 8 nm or less. . The particle number concentration of the fine particles 141 may be, for example, about 1.0×10 ⁶ to 1.0×10 ¹² /ml, and can be arbitrarily set according to the application. The median diameter or average particle diameter and particle number concentration can be measured, for example, by using a particle size distribution analyzer. As the particle size distribution measuring instrument, for example, a particle size distribution measuring instrument using a dynamic light scattering method (eg, Zetasizer Ultra manufactured by Malvern Panalytical, etc.) may be used.

The first fine particles 141f and the second fine particles 141s contained in the fine particles 141 can be arbitrarily selected, for example, as long as the particle diameter is within the range described above. Also, the difference between the median diameter D50f of the first fine particles 141f and the median diameter D50s of the second fine particles 141s is arbitrary.

For example, the particle number concentration of the first fine particles 141f is lower than the particle number concentration of the second fine particles 141s. Here, when the particle number concentration of the first fine particles 141f is higher than the particle number concentration of the second fine particles 141s, the possibility of the second fine particles 141s entering between the particles of the first fine particles 141f becomes low. For this reason, the degree of filling of the particles 141 between the electrodes 11 and 12 cannot be increased, and there is a concern that the particles 141 may be unevenly distributed. In contrast, according to the present embodiment, for example, the particle number concentration of the first fine particles 141f is lower than the particle number concentration of the second fine particles 141s. In this case, the filling degree of the fine particles 141 between the electrodes 11 and 12 can be increased. Therefore, it is possible to suppress uneven distribution of the fine particles 141 and the like.

For example, the work function of the first fine particles 141f is lower than the work function of the second fine particles 141s. In this case, electrons can easily move from the first electrode 11 and the first fine particles 141f toward the second fine particles 141s. In addition, since the inter-particle distance of the second fine particles 141s tends to be shorter than the inter-particle distance of the first fine particles 141f, an electron transfer path is easily formed in the intermediate portion 14 . Therefore, electrons are easily supplied from the first electrode 11 to the intermediate portion 14 via the second fine particles 141s. Thereby, the transmission of electrons between the electrodes 11 and 12 can proceed smoothly. Therefore, it is possible to improve the power generation amount.

The fine particles 141 include, for example, a conductive material, and any material is used depending on the application. The fine particles 141 may contain one type of material, or may contain a plurality of materials depending on the application. Note that when the fine particles 141 include a plurality of particles, in addition to including one type of material having different characteristics such as particle size and work function, the fine particles 141 may include a plurality of types of materials having the same or different characteristics as described above.

The fine particles 141 contain, for example, metal. As the fine particles 141, for example, in addition to particles containing one kind of material such as gold or silver, particles of an alloy containing two or more kinds of materials may be used.

Fine particles 141 contain, for example, a metal oxide. Examples of fine particles 141 containing metal oxides include zirconia (ZrO ₂ ), titania (TiO ₂ ), silica (SiO ₂ ), alumina (Al ₂ O ₃ ), iron oxides (Fe ₂ O ₃ , Fe ₂ O ₅ ), Copper oxide (CuO ₎ , zinc oxide (ZnO), yttria ( _Y2O3 ), niobium _oxide ( _Nb2O5 ) _, molybdenum oxide ( _MoO3 ), indium oxide ( _In2O3 ), tin oxide ( _SnO2 ), tantalum oxide (Ta ₂ O ₅ ), tungsten oxide (WO ₃ ), lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ), ceria (CeO ₂ ), antimony oxide (Sb ₂ O ₅ , Sb ₂ O ₃ ), a metal oxide of at least one element selected from the group consisting of metals and Si is used. Particulate 141 may include, for example, a dielectric.

The fine particles 141 may contain, for example, metal oxides other than magnetic substances. For example, if the fine particles 141 contain a metal oxide exhibiting a magnetic substance, the movement of the fine particles 141 may be restricted by the magnetic field generated due to the environment in which the power generating element 1 is installed. Therefore, by including a metal oxide other than a magnetic material, the fine particles 141 are not affected by the magnetic field caused by the external environment, and it is possible to suppress the decrease in the power generation amount over time.

The microparticles 141 include, for example, a coating 141a on the surface. The thickness of the coating 141a is, for example, a finite value of 20 nm or less. By providing such a film 141 a on the surface of the fine particles 141 , it is possible to suppress aggregation when dispersed in the non-conductor layer 142 , for example. Further, for example, electrons are more likely to move between the first electrode 11 and the microparticles 141, between the plurality of microparticles 141, and between the second electrode 12 and the microparticles 141 using the tunnel effect or the like. becomes possible.

A material having, for example, a thiol group or a disulfide group is used as the coating 141a. Alkanethiol such as dodecanethiol is used as the material having a thiol group. As a material having a disulfide group, for example, an alkane disulfide or the like is used.

The non-conductor layer 142 is provided between the electrodes 11 and 12 and is in contact with the electrodes 11 and 12, for example. The thickness of the non-conductor layer 142 is a finite value of 500 μm or less, for example. The thickness of the non-conductor layer 142 affects the value and variation of the gap G described above. Therefore, for example, when the thickness of the non-conductor layer 142 is 200 nm or less, variations in the gap G in the planes along the second direction X and the third direction Y may lead to a decrease in power generation. Also, if the thickness of the non-conductor layer 142 is greater than 1 μm, the electric field generated between the electrodes 11 and 12 may weaken. For these reasons, the thickness of the non-conductor layer 142 is preferably greater than 200 nm and equal to or less than 1 μm.

The non-conductor layer 142 may contain, for example, one type of material, or may contain a plurality of materials depending on the application. Materials described in ISO 1043-1 or JIS K 6899-1, for example, may be used as the non-conductor layer 142 . The non-conductor layer 142 may include a plurality of layers containing different materials, for example, and may include a structure in which each layer is laminated. When the non-conductor layer 142 includes a plurality of layers, for example, particles 141 containing different materials may be included (eg, dispersed) in each layer.

The non-conductor layer 142 has insulating properties, for example. The material used for the non-conductor layer 142 is arbitrary as long as it is a non-conductor material that can fix the fine particles 141 in a dispersed state, but an organic polymer compound is preferable. When the non-conductor layer 142 contains an organic polymer compound, the non-conductor layer 142 can be formed flexibly, so that the power generating element 1 can be formed in a shape such as curved or bent according to the application.

Examples of organic polymer compounds include polyimides, polyamides, polyesters, polycarbonates, poly(meth)acrylates, radically polymerizable photo- or thermosetting resins, photo-cationically polymerizable photo- or thermosetting resins, epoxy resins, and acrylonitrile components. can be used, such as copolymers containing

An inorganic substance may be used as the non-conductor layer 142, for example. Examples of inorganic substances include porous inorganic substances such as zeolite and diatomaceous earth, as well as cage-like molecules.

<First Substrate 15, Second Substrate 16>
The first substrate 15 and the second substrate 16 are spaced apart in the first direction Z with the electrodes 11 and 12 and the intermediate portion 14 interposed therebetween, as shown in FIG. 1A, for example. The first substrate 15 is, for example, in contact with the first electrode 11 and separated from the second electrode 12 . The first substrate 15 fixes the first electrode 11 . The second substrate 16 is in contact with the second electrode 12 and separated from the first electrode 11 . A second substrate 16 fixes the second electrode 12 .

The thickness of each of the substrates 15 and 16 along the first direction Z is, for example, 10 μm or more and 2 mm or less. The thickness of each substrate 15, 16 can be set arbitrarily. The shape of each of the substrates 15 and 16 may be, for example, square, rectangular, or disk-like, and can be arbitrarily set according to the application.

As the substrates 15 and 16, for example, plate-shaped members having insulation properties can be used, and known members such as silicon, quartz, and Pyrex (registered trademark) can be used. For each of the substrates 15 and 16, for example, a film-like member may be used, and for example, a known film-like member such as PET (polyethylene terephthalate), PC (polycarbonate), polyimide, or the like may be used.

For the substrates 15 and 16, for example, a member having conductivity can be used, such as iron, aluminum, copper, or an alloy of aluminum and copper. As the substrates 15 and 16, for example, a member such as a conductive polymer may be used in addition to a conductive semiconductor such as Si or GaN. If conductive members are used for the substrates 15 and 16, wiring for connecting to the electrodes 11 and 12 becomes unnecessary.

For example, if the first substrate 15 is a semiconductor, it may have a degenerate portion that contacts the first electrode 11 . In this case, the contact resistance between the first electrode 11 and the first substrate 15 can be reduced as compared with the case without the degenerate portion. Also, the first substrate 15 may have a recessed portion on a surface different from the surface in contact with the first electrode 11 . In this case, the contact resistance between the wiring (for example, the first wiring 101) electrically connected to the first substrate 15 can be reduced.

For example, when stacking a plurality of power generation elements 1 shown in FIG. In this case, contact resistance can be reduced by providing contraction portions on the contact surfaces of the substrates 15 and 16 that are in contact with each other as the power generation elements 1 are stacked.

The above-mentioned degenerate portion is generated, for example, by ion-implanting an n-type dopant into a semiconductor at a high concentration, coating a semiconductor with a material such as glass containing an n-type dopant, and performing heat treatment after coating.

As impurities to be doped into the semiconductor first substrate 15, known impurities such as P, As, Sb, etc. for n-type, and B, Ba, Al, etc. for p-type are mentioned. Further, electrons can be efficiently emitted when the impurity concentration in the degenerate portion is, for example, 1×10 ¹⁹ ions/cm ³ .

For example, when the first substrate 15 is a semiconductor, the specific resistance value of the first substrate 15 may be, for example, 1×10 ⁻⁶ Ω·cm or more and 1×10 ⁶ Ω·cm or less. If the resistivity value of the first substrate 15 is less than 1×10 ⁻⁶ Ω·cm, it is difficult to select the material. Also, if the specific resistance value of the first substrate 15 is greater than 1×10 ⁶ Ω·cm, there is a concern that current loss may increase.

In addition, although the case where the first substrate 15 is a semiconductor has been described above, the second substrate 16 may be a semiconductor. In this case, the description is omitted because it is the same as the above.

The power generation element 1 may include only the first substrate 15 as shown in FIG. 6(a), or may include only the second substrate 16, for example. Moreover, as shown in FIG. 6B, for example, the power generation element 1 has a laminated structure in which a plurality of the first electrode 11, the intermediate portion 14, and the second electrode 12 are laminated in this order without the respective substrates 15 and 16. (e.g. 1a, 1b, 1c, etc.), for example, a laminated structure comprising at least one of the substrates 15, 16 may be indicated.

Note that the intermediate portion 14 may contain a solvent 142s instead of the non-conductor layer 142, as shown in FIG. 7, for example. In this case, the fine particles 141 are dispersed in the solvent 142s. Moreover, each of the electrodes 11 and 12 is supported by a supporting portion (not shown). A known liquid such as water or toluene is used as the solvent 142s. Even in this case, it is possible to suppress a decrease in the power generation amount by including the above-described first fine particles 141f and second fine particles 141s.

Note that the intermediate portion 14 may not include the non-conductor layer 142, as shown in FIG. 8, for example. In this case, the gap G is filled with the fine particles 141 . Moreover, each of the electrodes 11 and 12 is supported by a supporting portion (not shown). Even in this case, it is possible to suppress a decrease in the power generation amount by including the above-described first fine particles 141f and second fine particles 141s.

<Example of operation of power generation element 1>
For example, when thermal energy is applied to the power generation element 1, a current is generated between the first electrode 11 and the second electrode 12, and the thermal energy is converted into electrical energy. The amount of current generated between the first electrode 11 and the second electrode 12 depends on thermal energy and also depends on the difference between the work function of the second electrode 12 and the work function of the first electrode 11 .

The amount of current generated can be increased, for example, by increasing the work function difference between the first electrode 11 and the second electrode 12 and by decreasing the gap G. For example, the amount of electrical energy generated by the power generation element 1 can be increased by considering at least one of increasing the work function difference and decreasing the gap G. Further, by providing the fine particles 141 between the electrodes 11 and 12, the amount of electrons moving between the electrodes 11 and 12 can be increased, which can lead to an increase in the amount of current.

　The "work function" indicates the minimum energy required to extract electrons in a solid into a vacuum. The work function is measured using, for example, ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), or Auger electron spectroscopy (AES). can be done. As the “work function”, in addition to using an actual measurement value for each configuration of the power generation element 1, for example, a known value measured for a material may be used.

(Embodiment: Method for manufacturing power generation element 1)
Next, an example of a method for manufacturing the power generating element 1 according to this embodiment will be described. FIG. 3 is a flow chart showing an example of a method for manufacturing the power generating element 1 according to this embodiment.

The method for manufacturing the power generating element 1 includes an element forming step S100, and may include, for example, a sealing material forming step S140.

<Element formation step S100>
The element forming step S100 forms the first electrode 11, the intermediate portion 14, and the second electrode 12, respectively. In the element forming step S100, for example, a plurality of first electrodes 11, intermediate portions 14, and second electrodes 12 may be laminated. In the element forming step S100, the first electrode 11, the intermediate portion 14, and the second electrode 12 are formed using, for example, a known forming technique. The element formation step S100 includes, for example, a first electrode formation step S110, an intermediate portion formation step S120, and a second electrode formation step S130. The order in which steps S110, S120, and S130 are performed is arbitrary.

<First Electrode Forming Step S110>
The first electrode forming step S110 forms the first electrode 11 . In the first electrode forming step S110, the first electrode 11 is formed on the first substrate 15, for example, as shown in FIG. 5(a). The first electrode 11 is formed, for example, by a sputtering method or a vacuum deposition method under a reduced pressure environment, or is formed by using a known electrode forming technique. In the first electrode forming step S110, for example, instead of the first substrate 15, the first electrode 11 may be formed by processing a stretched electrode material into an arbitrary size. In this case, the first substrate 15 may not be used.

In the first electrode forming step S110, the first electrode 11 may be formed on the first substrate 15, for example. For example, when a film member is used as the first substrate 15, the first electrode 11 can be applied onto the first substrate 15, and the first substrate 15 and the first electrodes 11 can be rolled up. After that, for example, in at least one of the intermediate portion forming step S120, the second electrode forming step S130, and the sealing material forming step S140, which will be described later, it may be cut into an area according to the application.

<Intermediate portion forming step S120>
In the intermediate portion forming step S120, the intermediate portion 14 including the non-conductor layer 142 is formed on the first electrode 11, as shown in FIG. 5B, for example. In the intermediate portion forming step S120, for example, a non-conductor material containing fine particles 141 is applied to the surface of the first electrode 11 or the like, and the non-conductor layer 142 is formed by curing the non-conductor material. As a result, the intermediate portion 14 including the non-conductor layer 142 containing the fine particles 141 is formed.

In the intermediate portion forming step S120, a non-conductive material is applied to the surface of the first electrode 11 by a known coating technique such as screen printing or spin coating. The film thickness of the non-conducting material can be arbitrarily set according to the design of the gap G described above.

As the non-conducting material, a polymer material with known insulating properties such as epoxy resin is used. As the non-conducting material, a thermosetting resin is used, and for example, an ultraviolet curable resin is used. In the intermediate portion forming step S120, the non-conductor layer 142 may be formed by heating, UV irradiation, or the like on the applied non-conductor material according to the properties of the non-conductor material.

In the intermediate portion forming step S120, for example, a fine particle material may be mixed in any inorganic material and laser irradiation may be performed. As a result, the non-conductor layer 142 containing the fine particles 141 is formed, and the intermediate portion 14 is formed.

<Second electrode forming step S130>
The second electrode forming step S130 forms the second electrode 12 on the non-conductor layer 142, as shown in FIG. 5C, for example. The second electrode 12 is formed using a material having a work function lower than that of the first electrode 11, for example. The second electrode 12 is formed using a known electrode forming technique such as nanoimprinting.

The second electrode forming step S130 is formed, for example, on the surface of the non-conductor layer 142 by sputtering or vacuum deposition under a reduced pressure environment. In this case, when the second electrode 12 is formed, the main surface of the second electrode 12 is in contact with the non-conductor layer 142 without being exposed to the air or the like. Therefore, fluctuations in the work function of the second electrode 12 can be suppressed. This makes it possible to further stabilize the power generation amount.

In the second electrode forming step S130, for example, the surface of the second electrode 12 provided in advance on the second substrate 16 is brought into contact with the surface of the non-conductor layer 142 to form the second electrode 12. good too. In this case, variations in the surface state of the second electrode 12 due to the surface state of the non-conductor layer 142 can be suppressed compared to the case where the second electrode 12 is formed directly on the surface of the non-conductor layer 142 . This makes it possible to increase the amount of power generation.

For example, when a film member is used as the second substrate 16, it can be realized by preparing the second substrate 16 coated with the second electrode 12. For example, the second substrate 16 and the second electrode 12 are wound into a roll. It can be prepared as is. After that, for example, before or after the sealing material forming step S140, which will be described later, it may be cut into areas according to the application.

In addition, in the second electrode forming step S130, for example, after the second electrode 12 is formed on the non-conductor layer 142, the intermediate portion 14 and the second electrode 12 may be heated. The heating of the intermediate portion 14 and the second electrode 12 may be performed, for example, instead of the heating in the intermediate portion forming step S120, or may be performed in addition to the heating in the intermediate portion forming step S120. In this case, the surface of the nonconductor layer 142 in contact with the second electrode 12 is easily flattened. Therefore, it is possible to suppress the generation of a slight gap between the non-conductor layer 142 and the second electrode 12 . This makes it possible to increase the amount of power generation.

<Sealing Material Forming Step S140>
For example, the sealing material forming step S140 may be performed after the element forming step S100 (for example, the second electrode forming step S130). In the sealing material forming step S140, the sealing material 17 is formed in contact with at least one of the first electrode 11, the intermediate portion 14, and the second electrode 12, as shown in FIG. The sealing material 17 is formed using a known technique such as nanoimprinting.

As the sealing material 17, an insulating material is used, for example, a known insulating resin such as a fluorine-based insulating resin is used. By forming the sealing material 17, deterioration of the non-conductor layer 142 and the fine particles 141 caused by the external environment can be suppressed. This makes it possible to improve the durability.

In particular, when the sealing material 17 is formed so as to cover the intermediate portion 14, the intermediate portion 14 is not exposed to the outside, so durability can be further improved.

The power generating element 1 in the present embodiment is formed by performing the steps described above. In addition, for example, a second substrate 16 shown in FIG. 1A may be formed on the second electrode 12 . Further, for example, by forming the wirings 101, 102, etc., the power generator 100 in the present embodiment is formed.

According to the present embodiment, the microparticles 141 include first microparticles 141f and second microparticles 141s having a smaller median diameter D50s than the first microparticles 141f. Therefore, it is possible to increase the possibility that the second fine particles 141s enter between the particles of the first fine particles 141f, and it is possible to suppress fluctuations in the dispersed state of the fine particles 141 . As a result, it is possible to suppress a decrease in the power generation amount.

Further, according to the present embodiment, the particle number concentration of the first fine particles 141f is lower than the particle number concentration of the second fine particles 141s. That is, the filling degree of the fine particles 141 between the electrodes 11 and 12 can be increased. Therefore, it is possible to further suppress fluctuations in the dispersed state of the fine particles 141 . As a result, it is possible to further suppress the decrease in the power generation amount.

Further, according to the present embodiment, the intermediate portion 14 includes the non-conductor layer 142 containing the fine particles 141 . That is, the non-conductor layer 142 suppresses movement of the fine particles 141 between the electrodes. Therefore, it is possible to prevent the fine particles 141 from becoming unevenly distributed on the one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Also, according to the present embodiment, the intermediate portion 14 includes the non-conductor layer 142 that supports the first electrode 11 and the second electrode 12 . Therefore, compared to the case where a solvent or the like is used instead of the non-conductor layer 142, there is no need to provide a supporting portion or the like for maintaining the distance (gap G) between the electrodes, and the accuracy of forming the supporting portion is reduced. Variation in the gap G can be eliminated. This makes it possible to increase the amount of power generation.

Further, according to the present embodiment, for example, the sealing material forming step S140 forms the sealing material 17 in contact with the first electrode 11, the intermediate portion 14, and the second electrode 12 after the second electrode forming step S130. may In this case, deterioration of the non-conductor layer 142 and the fine particles 141 due to the external environment can be suppressed. This makes it possible to improve the durability.

Further, according to the present embodiment, for example, the second electrode forming step S130 may form the second electrode 12 on the surface of the non-conductor layer 142 under a reduced pressure environment. In this case, fluctuations in the work function of the second electrode 12 can be suppressed. This makes it possible to further stabilize the power generation amount.

Further, according to the present embodiment, for example, the second electrode forming step S130 includes bringing the surface of the second electrode 12 provided on the second substrate 16 in advance and the surface of the non-conductor layer 142 into contact with each other. may contain. In this case, variations in the surface state of the second electrode 12 due to the surface state of the non-conductor layer 142 can be suppressed compared to the case where the second electrode 12 is formed directly on the surface of the non-conductor layer 142 . This makes it possible to increase the amount of power generation.

Also, according to the present embodiment, the non-conductor layer 142 may contain an organic polymer compound, for example. In this case, the non-conductor layer 142 can be formed flexibly. Thereby, it is possible to form the power generation element 1 having a shape according to the application.

Further, according to the present embodiment, for example, the intermediate portion 14 is provided on the first electrode 11 and includes a solid non-conductor layer 142 and fine particles 141 dispersed and fixed in the non-conductor layer 142. may contain. That is, the non-conductor layer 142 suppresses movement of the fine particles 141 between the electrodes (the first electrode 11 and the second electrode 12). In this case, it is possible to prevent the fine particles 141 from becoming unevenly distributed on one electrode side over time and reducing the amount of movement of electrons. This makes it possible to stabilize the power generation amount.

Further, according to this embodiment, for example, the intermediate portion 14 may be provided on the first electrode 11 and include a solid non-conductor layer 142 . Also, the second electrode 12 may be provided on the non-conductor layer 142 and have a work function different from that of the first electrode 11 . In this case, compared to the case where a solvent or the like is used instead of the non-conductor layer 142, there is no need to provide a support or the like for maintaining the distance (gap G) between the electrodes. Therefore, it is possible to eliminate the variation of the gap G to be applied. This makes it possible to increase the amount of power generation.

(Embodiment: electronic device 500)
<Electronic device 500>
The power generation element 1 and the power generation device 100 described above can be mounted on, for example, an electronic device. Some embodiments of the electronic device are described below.

FIGS. 9(a) to 9(d) are schematic block diagrams showing an example of an electronic device 500 including the power generation element 1. FIG. 9(e) to 9(h) are schematic block diagrams showing an example of an electronic device 500 having a power generation device 100 including the power generation element 1. FIG.

As shown in FIG. 9A, an electronic device 500 (electric product) includes an electronic component 501 (electronic component), a main power supply 502, and an auxiliary power supply 503. Each of the electronic device 500 and the electronic component 501 is an electrical device.

The electronic component 501 is driven using the main power supply 502 as a power supply. Examples of the electronic component 501 include, for example, a CPU, motors, sensor terminals, lighting, and the like. If electronic component 501 is, for example, a CPU, electronic device 500 includes an electronic device that can be controlled by a built-in master (CPU). If the electronic components 501 include at least one of, for example, motors, sensor terminals, and lighting, the electronic device 500 includes electronic devices that can be controlled by an external master or person.

The main power supply 502 is, for example, a battery. Batteries also include rechargeable batteries. A plus terminal (+) of the main power supply 502 is electrically connected to a Vcc terminal (Vcc) of the electronic component 501 . A negative terminal (−) of the main power supply 502 is electrically connected to a GND terminal (GND) of the electronic component 501 .

The auxiliary power supply 503 is the power generation element 1. The power generation element 1 includes at least one power generation element 1 described above. In the electronic device 500, the auxiliary power supply 503 is used, for example, together with the main power supply 502, and is used as a power supply for assisting the main power supply 502 or as a power supply for backing up the main power supply 502 when the capacity of the main power supply 502 runs out. be able to. If the main power source 502 is a rechargeable battery, the auxiliary power source 503 can also be used as a power source for charging the battery.

As shown in FIG. 9(b), the main power source 502 may be the power generation element 1. An electronic device 500 shown in FIG. 9B includes a power generation element 1 used as a main power supply 502 and an electronic component 501 that can be driven using the power generation element 1 . The power generation element 1 is an independent power supply (for example, an off-grid power supply). Therefore, the electronic device 500 can be, for example, an independent type (standalone type). Moreover, the power generating element 1 is of the energy harvesting type. The electronic device 500 shown in FIG. 9B does not require battery replacement.

The electronic component 501 may include the power generation element 1 as shown in FIG. 9(c). The anode of the power generation element 1 is electrically connected to, for example, a GND wiring of a circuit board (not shown). The cathode of the power generation element 1 is electrically connected to, for example, Vcc wiring of a circuit board (not shown). In this case, the power generating element 1 can be used as, for example, an auxiliary power source 503 for the electronic component 501 .

As shown in FIG. 9(d), when the electronic component 501 includes the power generation element 1, the power generation element 1 can be used as the main power source 502 of the electronic component 501, for example.

As shown in each of FIGS. 9(e) to 9(h), the electronic device 500 may include the power generator 100. FIG. The power generation device 100 includes a power generation element 1 as a source of electrical energy.

The embodiment shown in FIG. 9(d) comprises a power generation element 1 in which an electronic component 501 is used as a main power supply 502. Similarly, the embodiment shown in Figure 9(h) comprises a generator 100 in which an electronic component 501 is used as the main power source. In these embodiments, electronic component 501 has an independent power supply. Therefore, the electronic component 501 can be made self-supporting, for example. Free-standing electronic component 501 can be effectively used, for example, in an electronic device that includes multiple electronic components and in which at least one electronic component is separate from another electronic component. An example of such electronics 500 is a sensor. The sensor has a sensor terminal (slave) and a controller (master) remote from the sensor terminal. Each of the sensor terminals and controller is an electronic component 501 . If the sensor terminal is provided with the power generation element 1 or the power generation device 100, it becomes a self-supporting sensor terminal and does not require a wired power supply. Since the power generation element 1 or the power generation device 100 is of the energy harvesting type, it is unnecessary to replace the battery. A sensor terminal can also be regarded as one of the electronic devices 500 . The sensor terminals considered electronic equipment 500 further include, for example, IoT wireless tags, etc., in addition to sensor terminals of sensors.

Common to the embodiments shown in FIGS. 9A to 9H is that the electronic device 500 includes a power generation element 1 that converts thermal energy into electrical energy, and uses the power generation element 1 as a power source. and an electronic component 501 that can be driven.

The electronic device 500 may be an autonomous type with an independent power supply. Examples of autonomous electronic devices include, for example, robots. Furthermore, the electronic component 501 with the power generation element 1 or the power generation device 100 may be autonomous with an independent power supply. Examples of autonomous electronic components include, for example, movable sensor terminals.

Although several embodiments of the invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

Reference Signs List 1: power generation element 11: first electrode 12: second electrode 14: intermediate portion 15: first substrate 16: second substrate 17: sealing material 100: power generation device 101: first wiring 102: second wiring 140: space 141: Fine particles 141a: Coating 142: Non-conductor layer 142s: Solvent 500: Electronic device 501: Electronic component 502: Main power source 503: Auxiliary power source G: Gap R: Load S100: Element forming step S110: First electrode forming step S120: Intermediate portion forming step S130: Second electrode forming step S140: Sealing material forming step Z: First direction X: Second direction Y: Third direction

Claims (6)

A power generation element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy,
a first electrode;
an intermediate portion provided on the first electrode and containing fine particles;
a second electrode provided on the intermediate portion and having a work function different from that of the first electrode;
with
The fine particles are
A power generation element comprising: first fine particles; and second fine particles having a smaller median diameter than the first fine particles. The power generation element according to claim 1, wherein the particle number concentration of the first fine particles is lower than the particle number concentration of the second fine particles. 3. The power generation element according to claim 1, wherein the intermediate portion includes a non-conductor layer that encloses the fine particles and supports the first electrode and the second electrode. A method for manufacturing a power generation element that does not require a temperature difference between electrodes when converting thermal energy into electrical energy,
a first electrode;
an intermediate portion containing fine particles; and a second electrode having a work function different from that of the first electrode;
An element forming step for forming each,
The fine particles are
A method for producing a power generation element, comprising: first fine particles; and second fine particles having a smaller median diameter than the first fine particles. The power generation element according to claim 1;
a first wiring electrically connected to the first electrode;
a second wiring electrically connected to the second electrode;
A power generation device comprising: The power generation element according to claim 1;
An electronic device comprising: an electronic component driven by using the power generation element as a power supply.

Images