This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-071066, filed on Apr. 3, 2019; the entire contents of which are incorporated herein by reference.
Embodiments described herein relate generally to a power generation element, a power generation module, a power generation device, a power generation system, and a method for manufacturing the power generation element.
For example, there is a power generation element that generates power in response to heat from a heat source. It is desirable to stably increase the efficiency of the power generation element.
According to one embodiment, a power generation element includes a first conductive layer, a second conductive layer, a first member, and a second member. The first member is provided between the first conductive layer and the second conductive layer. The first member includes a first crystal region and a first layer region. The first crystal region is between the first layer region and the first conductive layer. An orientation from negative to positive of a polarization of the first crystal region has a component in a first orientation. The first orientation is from the first conductive layer toward the second conductive layer. The first layer region includes a first layer-shaped portion spreading along a first surface. The first surface crosses the first orientation. The first layer-shaped portion includes at least one selected from the group consisting of graphene and a transition metal dichalcogenide. The second member is provided between the first member and the second conductive layer and separated from the first member.
According to another embodiment, a power generation element includes a first conductive layer, a second conductive layer, a first member, and a second member. The first member is provided between the first conductive layer and the second conductive layer. The first member includes a first crystal region, a first layer region, and a first intermediate region. The first crystal region is between the first layer region and the first conductive layer. An orientation from negative to positive of a polarization of the first crystal region has a component in a first orientation. The first orientation is from the first conductive layer toward the second conductive layer. The first intermediate region is provided between the first layer region and the first crystal region. The first intermediate region includes at least one selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra. The second member is provided between the first member and the second conductive layer and separated from the first member.
According to another embodiment, a method for manufacturing a power generation element is disclosed. The method can includes forming a first structure body, and causing the first structure body and a second structure body to oppose each other and to be separated from each other. The forming of the first structure body includes forming a first member on a first substrate, forming a first conductive layer on the first crystal region, and removing the first substrate. The first member includes a first layer region and a first crystal region. The first layer region is between the first substrate and the first crystal region. An orientation from negative to positive of a polarization of the first crystal region has a component in an orientation from the first substrate toward the first crystal region. The first layer region includes a first layer-shaped portion. The first layer-shaped portion includes at least one selected from the group consisting of graphene and a transition metal dichalcogenide. The first layer-shaped portion is between the first crystal region and the second structure body in the causing of the first structure body and the second structure body to oppose each other.
According to another embodiment, a method for manufacturing a power generation element is disclosed. The method includes forming a first structure body, and causing the first structure body and a second structure body to oppose each other and to be separated from each other. The forming of the first structure body includes forming a first member on a first substrate, and forming a first conductive layer. The first substrate is conductive. The first member includes a first layer region and a first crystal region. The first crystal region is between the first substrate and the first layer region. An orientation from negative to positive of a polarization of the first crystal region has a component in an orientation from the first substrate toward the first crystal region. The first layer region includes a first layer-shaped portion. The first layer-shaped portion includes at least one selected from the group consisting of graphene and a transition metal dichalcogenide. The first crystal region is between the first conductive layer and the first layer region. The first substrate is between the first conductive layer and the first crystal region. The first layer-shaped portion is between the first crystal region and the second structure body in the causing of the first structure body and the second structure body to oppose each other.
As shown in
The first member 10M is provided between the first conductive layer E1 and the second conductive layer E2. The second member 20M is provided between the first member 10M and the second conductive layer E2.
The direction from the first conductive layer E1 toward the second conductive layer E2 is taken as a Z-axis direction. One direction perpendicular to the Z-axis direction is taken as an X-axis direction. A direction perpendicular to the Z-axis direction and the X-axis direction is taken as a Y-axis direction.
In one example, at least a portion of the first conductive layer E1 and at least a portion of the second conductive layer E2 are substantially parallel to the X-Y plane. In one example, at least a portion of the first member 10M and at least a portion of the second member 20M are substantially parallel to the X-Y plane.
The second member 20M is separated from the first member 10M. A gap 40 is provided between the first member 10M and the second member 20M. The gap 40 is in a reduced-pressure state. For example, a container 70 is provided. For example, the first member 10M and the second member 20M are provided in the container 70. The interior of the container 70 is in a reduced-pressure state. Thereby, the gap 40 is in a reduced-pressure state.
For example, the first member 10M is electrically connected to the first conductive layer E1. The second member 20M is electrically connected to the second conductive layer E2. A first terminal 71 and a second terminal 72 are provided. The first terminal 71 is electrically connected to the first conductive layer E1. The second terminal 72 is electrically connected to the second conductive layer E2. A load 30 is electrically connectable between the first terminal 71 and the second terminal 72.
The load 30 is electrically connected to the first conductive layer E1 by first wiring 71a. In the example, the connection is performed via the first terminal 71. The load 30 is electrically connected to the second conductive layer E2 by second wiring 72a. In the example, the connection is performed via the second terminal 72. The power generation element 110 may include the container 70, the first terminal 71, and the second terminal 72. The power generation element 110 may include the first wiring 71a and the second wiring 72a.
The temperature of the first member 10M may be considered to be substantially equal to the temperature of the first conductive layer E1 due to thermal conduction. The temperature of the second member 20M may be considered to be substantially equal to the temperature of the second conductive layer E2 due to thermal conduction.
The temperature of the first conductive layer E1 and the temperature of the first member 10M are taken as a first temperature T1. The temperature of the second conductive layer E2 and the temperature of the second member 20M are taken as a second temperature T2. In one example, the first temperature T1 is set to be higher than the second temperature T2. For example, such a temperature difference can be provided by causing the first conductive layer E1 or the first member 10M to approach or contact a heat source.
In the embodiment, a current I1 flows in the first wiring 71a from the first conductive layer E1 toward the load 30 when such a temperature difference is provided. The current I1 flows in the second wiring 72a from the load 30 toward the second conductive layer E2. The current I1 is the electrical power obtained from the power generation element 110.
It is considered that the current I1 is based on the movement of electrons 51. For example, the electrons 51 are emitted from the first member 10M toward the gap 40. The electrons 51 that move through the gap 40 reach the second member 20M. The electrons 51 flow in the second conductive layer E2 via the second member 20M and reach the load 30 via the second wiring 72a. The electrons 51 flow to the first conductive layer E1 and the first member 10M via the first wiring 71a.
In the embodiment as shown in
The first crystal region 11c has polarization. The orientation from negative (−σ) toward positive (+σ) of the polarization has a component in a first orientation from the first conductive layer E1 toward the second conductive layer E2.
In one example, the first crystal region 11c has a wurtzite structure. The <000-1> direction of the first crystal region 11c has a component in the first orientation recited above (the first orientation from the first conductive layer E1 toward the second conductive layer E2).
For example, the first crystal region 11c includes a nitride semiconductor. For example, the first crystal region 11c includes AlN. In such a case, a surface 11ca of the first crystal region 11c opposing the first layer region 21r is, for example, substantially the −c plane (the (000-1) plane). A surface 11cb of the first crystal region 11c opposing the first conductive layer E1 is, for example, substantially the +c plane (the (0001) plane).
As shown in
In the embodiment, the electrons 51 can be emitted efficiently from the first member 10M by using the first crystal region 11c recited above. The efficiency of the power generation can be increased thereby.
There are cases where the front surface of the first crystal region 11c is altered. For example, when the first crystal region 11c is AlN, there are cases where the front surface of the AlN is oxidized; and an oxide film is formed. It was found that changes such as oxidization, etc., occur particularly easily when the front surface of the AlN (the surface from which the electrons 51 are emitted) is the −c plane (the (000-1) plane).
The first layer region 21r recited above is provided in the embodiment. The alteration of the front surface of the first crystal region 11c is suppressed thereby. A power generation element can be provided in which the efficiency can be increased stably thereby.
As shown in
As shown in
In the embodiment, the first intermediate region 21a includes, for example, at least one selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra (a first element 31). By providing the first intermediate region 21a, for example, the efficiency of the emission of the electrons from the first member 10M increases.
At least one first layer-shaped portion 21p is provided between the first intermediate region 21a and the second member 20M. Thereby, for example, scattering of the first element 31 by becoming separated from the first member 10M can be suppressed. For example, the first element 31 remains easily in the first member 10M. Thereby, a high efficiency is obtained stably due to the first element 31.
As shown in
The type of the first element 31 included in the first intermediate region 21a provided between the one of the multiple first layer-shaped portions 21p and the other one of the multiple first layer-shaped portions 21p and the type of the first element 31 included in the first intermediate region 21a provided between the first layer region 21r and the first crystal region 11c may be different from each other.
In one example, the first layer-shaped portion 21p includes graphene. The first intermediate region 21a includes Cs.
In the embodiment, the first crystal region 11c may include at least one selected from the group consisting of BaTiO3, PbTiO3, Pb(Zrx, Ti1-x)O3, KNbO3, LiNbO3, LiTaO3, NaxWO3, Zn2O3, Ba2NaNb5O5, Pb2KNb5O15, and Li2B4O7.
In the example as shown in
The orientation from negative (−σ) toward positive (+σ) of the polarization of the second crystal region 12c has a component in a second orientation from the second conductive layer E2 toward the first conductive layer E1.
For example, the second crystal region 12c has a wurtzite structure. The <000-1> direction of the second crystal region 12c has a component in the second orientation recited above (the second orientation from the second conductive layer E2 toward the first conductive layer E1).
For example, the second crystal region 12c includes a nitride semiconductor. For example, the second crystal region 12c includes AlN. In such a case, a surface 12ca of the second crystal region 12c opposing the second layer region 22r is, for example, substantially the −c plane (the (000-1) plane). A surface 12cb of the second crystal region 12c opposing the second conductive layer E2 is, for example, substantially the +c plane (the (0001) plane).
For example, the second layer region 22r includes a second layer-shaped portion 22p. The second layer-shaped portion 22p spreads along a second surface (e.g., the X-Y plane) crossing the second orientation recited above. The second layer-shaped portion 22p includes at least one selected from the group consisting of graphene and a transition metal dichalcogenide. The transition metal is a compound including a Group 16 element other than oxygen. The transition metal dichalcogenide is represented by the chemical formula MX2. “M” is a transition metal element. The transition metal element includes, for example, at least one selected from the group consisting of Mo and W. “X” is a Group 16 element other than oxygen. The transition metal dichalcogenide includes, for example, at least one selected from the group consisting of MoS2 and WS2. For example, the layer surface of the graphene is substantially along the X-Y plane. The layer surface of the transition metal dichalcogenide is along the X-Y plane.
By using the second crystal region 12c recited above, the electrons 51 that are emitted from the second member 20M efficiently enter the second member 20M. For example, the efficiency of the power generation can be increased. By providing the second layer region 22r recited above, for example, the alteration of the front surface of the second crystal region 12c is suppressed. For example, a power generation element can be provided in which the efficiency can be increased more stably.
The configuration of the second member 20M may be similar to the configuration of the first member 10M. Thereby, a power generation element in which the efficiency can be increased stably can be manufactured with high productivity.
As shown in
As shown in
By providing the second intermediate region 22a, for example, the efficiency of the electrons entering the second member 20M increases. For example, by setting the configuration of the second member 20M to be similar to the configuration of the first member 10M, a power generation element in which the efficiency can be increased stably can be manufactured with high productivity.
At least one second layer-shaped portion 22p is provided between the second intermediate region 22a and the first member 10M. Thereby, for example, scattering of the second element 32 by becoming separated from the second member 20M can be suppressed. For example, the second element 32 remains easily in the second member 20M. Thereby, a high efficiency is obtained stably due to the second element 32.
As shown in
The type of the second element 32 included in the second intermediate region 22a provided between the one of the multiple second layer-shaped portions 22p and the other one of the multiple second layer-shaped portions 22p and the type of the second element 32 included in the second intermediate region 22a provided between the second layer region 22r and the second crystal region 12c may be different from each other.
In one example, the second layer-shaped portion 22p includes graphene. The second intermediate region 22a includes Cs.
In the embodiment, the second crystal region 12c may include at least one selected from the group consisting of BaTiO3, PbTiO3, Pb(Zrx, Ti1-x)O3, KNbO3, LiNbO3, LiTaO3, NaxWO3, Zn2O3, Ba2NaNb5O5, Pb2KNb5O15, and Li2B4O7.
As shown in
The first intermediate region 21a is provided between the first layer region 21r and the first crystal region 11c. The first intermediate region 21a includes at least one selected from the group consisting of Li, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, and Ra (the first element 31).
The second member 20M is provided between the first member 10M and the second conductive layer E2. The second member 20M is separated from the first member 10M.
In the second embodiment as well, for example, the efficiency of the emission of the electrons from the first member 10M is increased by providing the first intermediate region 21a including the first element 31.
At least a portion of the first layer region 21r is provided between the first intermediate region 21a and the second member 20M (referring to
As shown in
At least a portion of the configuration described in reference to the second member 20M in the first embodiment is applicable to the second embodiment.
As shown in
In the first embodiment and the second embodiment, the thickness along the Z-axis direction of at least one of the first crystal region 11c or the second crystal region 12c is, for example, not less than 1 nm and not more than 3000 nm. The thickness along the Z-axis direction of at least one of the first layer region 21r or the second layer region 22r is, for example, not less than 0.3 nm and not more than 30 nm. The length in the Z-axis direction of the gap 40 is, for example, not less than 0.1 μm and not more than 50 μm.
A third embodiment relates to a method for manufacturing a power generation element.
Several examples of step S110 will now be described.
In the example shown in
For example, a first substrate 50s is prepared as shown in
As shown in
As shown in
Thus, in step S111, for example, the first member 10M that includes the first layer region 21r and the first crystal region 11c is formed on the first substrate 50s (referring to
As shown in
In step S117 as shown in
In step S118 as shown in
In the example, for example, after the process of
As shown in
The second structure body SB2 is prepared separately. The second structure body SB2 may be formed by a method similar to the method for manufacturing the first structure body SB1.
In step S120 recited above (causing the opposing), the first layer-shaped portion 21p is between the first crystal region 11c and the second structure body SB2 (referring to
For example, the first element 31 recited above may be introduced to the first layer region 21r between the process of
As shown in
As shown in
In the example as well, as described in reference to
For example, the first substrate 50s is prepared as shown in
As shown in
As shown in
As shown in
As shown in
The second structure body SB2 is prepared separately. The second structure body SB2 may be formed by a method similar to the method for manufacturing the first structure body SB1.
In step S120 recited above (the causing to oppose), the first layer-shaped portion 21p is between the first crystal region 11c and the second structure body SB2 (referring to
According to a manufacturing method such as that recited above, a power generation element can be manufactured in which the efficiency can be increased stably.
As shown in
As shown in
As shown in
As shown in
As shown in
For example, the power generation system 410 includes the power generation device 310. In the example, multiple power generation devices 310 are provided. In the example, the power generation system 410 includes the power generation device 310 and a drive device 66. The drive device 66 causes the power generation device 310 to follow the movement of the sun 61. By following the movement of the sun 61, efficient power generation can be performed.
Highly efficient power generation can be performed by using the power generation element 110 (or the power generation element 120) according to the embodiment.
According to the embodiments, a power generation element, a power generation module, a power generation device, a power generation system, and a method for manufacturing a power generation element can be provided in which the efficiency can be increased stably.
In the specification, “nitride semiconductor” includes all compositions of semiconductors of the chemical formula BxInyAlzGa1-x-y-zN (0≤x≤1, 0≤y≤1, 0≤z≤1, and x+y+z≤1) for which the composition ratios x, y, and z are changed within the ranges respectively. “Nitride semiconductor” further includes Group V elements other than N (nitrogen) in the chemical formula recited above, various elements added to control various properties such as the conductivity type and the like, and various elements included unintentionally.
Hereinabove, exemplary embodiments of the invention are described with reference to specific examples. However, the embodiments of the invention are not limited to these specific examples. For example, one skilled in the art may similarly practice the invention by appropriately selecting specific configurations of components included in power generation elements such as conductive layers, member crystal regions, layer regions, terminals, etc., from known art. Such practice is included in the scope of the invention to the extent that similar effects thereto are obtained.
Further, any two or more components of the specific examples may be combined within the extent of technical feasibility and are included in the scope of the invention to the extent that the purport of the invention is included.
Moreover, all power generation elements, power generation modules, power generation devices, power generation systems, and methods for manufacturing power generation elements practicable by an appropriate design modification by one skilled in the art based on the power generation elements, the power generation modules, the power generation devices, the power generation systems, and the methods for manufacturing power generation elements described above as embodiments of the invention also are within the scope of the invention to the extent that the purport of the invention is included.
Various other variations and modifications can be conceived by those skilled in the art within the spirit of the invention, and it is understood that such variations and modifications are also encompassed within the scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
Number | Date | Country | Kind |
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2019-071066 | Apr 2019 | JP | national |