CN113659064A

CN113659064A - Thermoelectric device and thermoelectric apparatus

Info

Publication number: CN113659064A
Application number: CN202010399566.1A
Authority: CN
Inventors: 刘方诚; 辛凯; 刘云峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-05-12
Filing date: 2020-05-12
Publication date: 2021-11-16
Anticipated expiration: 2040-05-12

Abstract

The application provides a thermoelectric device and a thermoelectric device, and relates to the technical field of semiconductors; the thermoelectric device has the advantages of low heat loss and high output power; the thermoelectric device comprises a hot end substrate, a cold end substrate, a thermoelectric unit and a support piece; the thermoelectric unit includes: at least one first thermoelectric leg and at least one second thermoelectric leg in series; two ends of each thermoelectric arm are connected with different end conductive connecting pieces, and the two thermoelectric arms connected in series are connected through the same end conductive connecting piece; the types of two adjacent thermoelectric arms are different; the first thermoelectric arm comprises a nanowire cluster mainly formed by a P-type semiconductor thermoelectric material, and the second thermoelectric arm comprises a nanowire cluster mainly formed by an N-type semiconductor thermoelectric material; two end conductive connecting pieces connected with two ends of the thermoelectric arm are connected with different substrates; the nanowire clusters are arranged in parallel with the hot end substrate and the cold end substrate and are not in direct contact with each other; the support pieces are located on the periphery of the thermoelectric unit and connected with the hot end substrate and the cold end substrate.

Description

Thermoelectric device and thermoelectric apparatus

Technical Field

The present application relates to the field of semiconductor technology, and more particularly, to a thermoelectric device and a thermoelectric apparatus.

Background

The thermoelectric material is a functional material capable of directly converting heat energy and electric energy mutually, mainly uses semiconductor material, and the thermoelectric device made of thermoelectric material has the advantages of small size, light weight and long service life. Compared with the traditional thermoelectric material, the low-dimensional nano material such as a superlattice structure, a carbon nano tube, a silicon nano wire, a quantum dot superlattice and the like can reduce the thermal conductivity of the material and improve the thermoelectric conversion efficiency and the power generation capacity of a system by increasing lattice scattering through a size effect, and the thermoelectric material becomes a research hotspot of a thermoelectric conversion mode in recent years.

In the prior art, a planar thermoelectric device is provided, in which a thermoelectric material having a low-dimensional single-layer structure (generally, a planar etching process) is disposed on a substrate to realize thermoelectric conversion, and on one hand, the thermoelectric material having a single-layer structure is employed, and the spatial arrangement density thereof is low, which results in a limitation of output power of the thermoelectric device; on the other hand, when the thermoelectric material is directly attached to the substrate, the substrate may dissipate heat flowing through the thermoelectric material, resulting in heat flow loss (i.e., heat loss), which may result in low thermoelectric conversion efficiency of the thermoelectric device.

Disclosure of Invention

The present application provides a thermoelectric device and a thermoelectric apparatus, which have advantages of low heat loss and high thermoelectric conversion rate.

The application provides a thermoelectric device, which comprises a hot end substrate and a cold end substrate which are oppositely arranged; the thermoelectric device further includes: a thermoelectric unit and a support member disposed between the hot side substrate and the cold side substrate; the thermoelectric unit includes: at least one first thermoelectric leg and at least one second thermoelectric leg in series; the two ends of the first thermoelectric arm and the second thermoelectric arm are respectively connected with different end conductive connecting pieces, and the ends of the two thermoelectric arms connected in series are connected through the same end conductive connecting piece; in the thermoelectric unit, one of any two adjacent thermoelectric legs connected in series is the first thermoelectric leg, and the other is the second thermoelectric leg; that is, the type of connecting the two thermoelectric arms is not feasible; the first thermoelectric arm comprises a first nanowire cluster mainly formed by a P-type semiconductor thermoelectric material, namely, the majority carriers of the first thermoelectric arm are holes; the second thermoelectric leg includes a second nanowire cluster formed primarily of an N-type semiconductor thermoelectric material, i.e., majority carriers of the second thermoelectric leg are electrons. In addition, in order to ensure that the first thermoelectric arm and the second thermoelectric arm in the thermoelectric unit can drive carriers in the semiconductor thermoelectric material to directionally migrate at the temperature difference between the cold source and the heat source so as to generate current, one of the two end conductive connecting pieces connected with the two ends of the first thermoelectric arm and the second thermoelectric arm is connected with the hot-end substrate, and the other end conductive connecting piece is connected with the cold-end substrate. Meanwhile, in order to disperse heat flows flowing through the nanowire clusters by the hot end substrate and the cold end substrate, the first nanowire cluster and the second nanowire cluster are arranged in the thermoelectric device and are not in direct contact with the hot end substrate and the cold end substrate; the first nanowire cluster and the second nanowire cluster are arranged in parallel with the hot end substrate and the cold end substrate (namely the thermoelectric device is a planar thermoelectric device); the support pieces are located on the periphery of the thermoelectric unit and connected with the hot end substrate and the cold end substrate, effective strength support between the hot end substrate and the cold end substrate is achieved through the support pieces, the whole thermoelectric device has certain mechanical strength, and therefore the fact that the nanowire clusters are not damaged due to external force under the condition that the nanowire clusters are separated from the substrates is guaranteed.

In summary, in the thermoelectric device provided in the embodiment of the present application, on one hand, the nanowire clusters (the first nanowire cluster and the second nanowire cluster) in the thermoelectric arm are parallel to the hot-end substrate and the cold-end substrate and are not in direct contact with each other, that is, the nanowire clusters are suspended; therefore, the heat flow of the nano-wire clusters which are dispersedly flowed through by the hot end substrate and the cold end substrate is avoided, the heat loss is reduced, and the thermoelectric conversion efficiency and the output power of the thermoelectric device are improved. On the other hand, through around thermoelectric unit, set up the support piece all connected with hot junction base plate and cold junction base plate, realize effectual intensity between hot junction base plate and cold junction base plate and support for whole thermoelectric device possesses certain mechanical strength, has guaranteed that the nanowire cluster does not take place to damage because of external force under the condition of breaking away from the base plate.

In some possible implementations, the support is a sealed annular structure; the supporting piece is made of a material with the heat conductivity coefficient less than or equal to 1W/mK; so as to ensure that the thermoelectric unit is positioned in a relatively closed space, isolate the convection current of the nanowire cluster and the outside air, and further reduce the heat loss of the nanowire cluster.

In some possible implementations, the first thermoelectric arm includes a plurality of the first nanowire clusters connected in series by an intermediate conductive connection; and/or, the second thermoelectric arm comprises a plurality of the second nanowire clusters connected in series by an intermediate electrically conductive connection; in order to fix the middle conductive connecting piece, the middle conductive connecting piece is connected with the hot end substrate or the cold end substrate through a supporting connecting piece; the supporting connecting piece is made of a material with the heat conductivity coefficient less than or equal to 1W/mK, so that heat flow is prevented from being dispersed to a hot end substrate or a cold end substrate connected with the supporting connecting piece through the middle conductive connecting piece. Under this condition, guaranteed that the thermoelectric arm forms sufficient isolation distance between cold junction and hot junction, increased the hot road distance between cold junction and the hot junction, formed better cold junction and hot junction and keep apart, effectively maintained the difference in temperature of cold junction and hot junction, and then improved thermoelectric device's thermoelectric conversion efficiency.

In some possible implementations, the first thermoelectric arm includes one of the first nanowire clusters connected between two of the end conductive connections, the first nanowire cluster being growth-connected between two opposing sides of the two end conductive connections; or the first thermoelectric arm comprises two first nanowire clusters which are connected between the two end conductive connecting pieces and are connected in series through a middle conductive connecting piece, and the two first nanowire clusters are respectively connected between opposite side surfaces of the middle conductive connecting piece and the two end conductive connecting pieces in a growing mode; said second thermoelectric leg comprising one said second nanowire cluster connected between two said end conductive connections, said second nanowire cluster being growth connected between opposing sides of two said end conductive connections; or the second thermoelectric arm comprises two second nanowire clusters which are connected between the two end conductive connecting pieces and are connected in series through a middle conductive connecting piece, and the two second nanowire clusters are respectively connected between the middle conductive connecting piece and the opposite side faces of the two end conductive connecting pieces in a growing mode.

In some possible implementations, the thermoelectric unit includes a plurality of the first thermoelectric legs and a plurality of the second thermoelectric legs; the two end conductive connecting pieces connected with two ends of the thermoelectric unit are arranged on the same side of the first thermoelectric arms and the second thermoelectric arms; the two end conductive connecting pieces connected with the two ends of the thermoelectric unit are connected with one of the hot end substrate and the cold end substrate; so as to simplify the connection circuit between the anode and the cathode at the two ends of the thermoelectric device and other devices in the thermoelectric device.

In some possible implementations, the thermoelectric unit includes a plurality of the first thermoelectric legs and a plurality of the second thermoelectric legs that are alternately connected in series in sequence through the end conductive connection, and the plurality of the first thermoelectric legs and the plurality of the second thermoelectric legs are distributed in two rows and two columns; wherein the first nanowire cluster and the second nanowire cluster both extend in a row direction; one of the two thermoelectric arms in the same row is the first thermoelectric arm, and the other one is the second thermoelectric arm; the plurality of thermoelectric arms positioned in the same column are sequentially and alternately connected in series through the end conductive connecting piece; the two thermoelectric arms positioned in the first row or the last row are connected in series through the end conductive connecting piece; end conductive connecting pieces connected with two ends of each thermoelectric arm are distributed at two ends of each thermoelectric arm along the extending direction of the thermoelectric arms.

In some possible implementations, the hot side substrate and the cold side substrate are both rectangular.

In some possible implementations, the thermoelectric unit includes a plurality of the first thermoelectric arms and a plurality of the second thermoelectric arms that are alternately connected in series in sequence through the end conductive connecting member, and the plurality of the first thermoelectric arms and the plurality of the second thermoelectric arms are uniformly distributed along a circumference of the first circular ring; wherein the extending direction of the first nanowire cluster and the second nanowire cluster is consistent with the extending direction of the thermoelectric arm; and the end part conductive connecting pieces connected with the two ends of each thermoelectric arm are distributed at the two ends of each thermoelectric arm along the radius direction of the first circular ring.

In some possible implementations, the hot end substrate and the cold end substrate are both circular.

In some possible implementations, the hot end substrate and the cold end substrate are metalized ceramic substrates.

In some possible implementations, the material used for the support member and/or the support connection member includes silicon gel or glass.

The embodiment of the application also provides a thermoelectric device, which comprises the thermoelectric device, the electric energy conversion system and the load in any one of the possible implementation manners; the thermoelectric device is connected with the load through the electric energy conversion system.

In some possible implementations, the thermoelectric device is a wearable device.

Drawings

FIG. 1 is a schematic diagram of a thermoelectric device according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a thermoelectric device according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating a thermoelectric principle of a thermoelectric device according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a thermoelectric device provided in an embodiment of the present application;

FIG. 5 is a schematic cross-sectional view taken along line CC' of FIG. 4;

FIG. 6 is a schematic structural diagram of a thermoelectric device according to an embodiment of the present disclosure;

FIG. 7 is a schematic structural diagram of a thermoelectric device according to an embodiment of the present disclosure;

FIG. 8 is a schematic cross-sectional view taken along the position DD' in FIG. 7;

fig. 9 is a schematic structural diagram of a thermoelectric device according to an embodiment of the present application.

Detailed Description

To make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be fully described below with reference to the accompanying drawings in the present application, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first," "second," and the like in the description examples and claims of this application and in the drawings are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, nor order. Furthermore, the terms "comprises" and "comprising," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such as a list of steps or elements. A method, system, article, or apparatus is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, system, article, or apparatus. "Upper," "lower," and the like are used solely in relation to the orientation of the components in the figures, and these directional terms are relative terms that are used for descriptive and clarity purposes and that will vary accordingly depending on the orientation in which the components in the figures are placed.

It should be understood that in the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" for describing an association relationship of associated objects, indicating that there may be three relationships, e.g., "a and/or B" may indicate: only A, only B and both A and B are present, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single item(s) or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

The embodiment of the application provides a thermoelectric device, as shown in fig. 1, the thermoelectric device comprises a thermoelectric device 1, an electric energy conversion system 2, a load 3; the load 3 is connected to the thermoelectric device 1 through the thermoelectric conversion system 2. In the working process of the thermoelectric device, heat energy flows from a heat source to a cold source (in the direction of a dotted arrow in fig. 1), passes through the thermoelectric device 1 on the way, is converted into electric energy through the thermoelectric device 1 and is output to the electric energy conversion system 2, and the electric energy conversion system 2 is responsible for boosting or reducing the voltage to adjust the voltage to the voltage matched with the load 3, so that the electric energy is supplied to the load 3 for use.

The thermoelectric device can be electronic products such as wearable equipment such as smart watches, smart bracelets, but is not limited to this, and can also be other electronic products such as cell-phones, industrial sensing equipment.

Taking this thermoelectric device as an example of a smart watch, as shown in fig. 2, the thermoelectric device 1 can be placed on a thermal path of a human body radiating to the environment, according to a thermoelectric effect (seebeck effect) of a semiconductor, the temperature of the human body is generally higher than the temperature of the environment, the human body is used as a heat source of the thermoelectric device 1, heat energy is continuously released to the environment, the thermoelectric device 1 continuously generates electric energy, and the voltage is increased or decreased through the electric energy conversion system 2, so that the power supply requirement of the load 3 of the smart watch is met.

Illustratively, in the smart watch, the power conversion system 2 may include a power chip and a peripheral circuit; the load 3 may include a processor (e.g., a central processing unit), a display module (e.g., a liquid crystal display), a communication module (e.g., a transceiver), and the like.

Of course, in addition to using human body as the heat source of thermoelectric devices, in some industrial application fields, the large temperature difference between the industrial heat source and the environment can be utilized, so that more heat energy is converted into electric energy through the thermoelectric devices, and the electric energy is supplied to devices such as industrial sensors.

The thermoelectric device that the thermoelectric device of this application adopted is through adopting the unsettled high density semiconductor nanowire cluster that sets up as the thermoelectric arm, has reduced thermoelectric device heat waste, has improved thermoelectric device's thermoelectric conversion efficiency. The following examples further illustrate specific arrangements of thermoelectric devices provided in the examples of the present application.

First, the principle of power generation of the thermoelectric device will be briefly described below.

Referring to fig. 3, the smallest thermoelectric unit in the thermoelectric device is a pair of thermocouples (i.e., two thermoelectric legs), one of which is mainly composed of P-type semiconductor thermoelectric material, i.e., the majority carriers are holes (represented as "+" in fig. 3); the other of the arms is composed mainly of N-type semiconductor thermoelectric material, i.e., the majority carriers are electrons (denoted as "-" in fig. 3). One end of the two thermoelectric arms passes through the same conductive structure T_coldConnected with the other end of the conductive structure T respectively_hotConnecting; conductive structure T_coldConnected with cold source and conductive structure T_hotConnected to a heat source (of course, the heat source and the heat source are relative), the temperature difference between the heat source and the heat source drives the carriers in the semiconductor thermoelectric material to perform directional migration, thereby generating the current I. Certainly, the direction of the current I has certain correlation with the arrangement directions of the cold source and the heat source; as shown in fig. 3, if the upper end is a cold source and the lower end is a heat source, the direction of the current is from left to right; if the upper end is a heat source and the lower end is a cold source, the direction of the current is from right to left.

With reference to fig. 4 and 5 (fig. 4 is a schematic cross-sectional view taken along a position CC'), the thermoelectric device 1 provided by the embodiment of the present application includes a hot-side substrate 10 and a cold-side substrate 20 disposed opposite to each other; in practical applications, the hot side substrate 10 may be connected to a heat source, and the cold side substrate 20 may be connected to a cold source. While fig. 5 is only illustrated schematically with the hot side substrate 10 below and the cold side substrate 20 above, in other implementations, the hot side substrate 10 may be above and the cold side substrate 20 below.

Illustratively, in some possible implementations, the hot-side substrate 10 and the cold-side substrate 20 may be metalized ceramic substrates; such as alumina (Al)₂O₃) Ceramic substrates, aluminum nitride (AlN) ceramic substrates, and the like.

As shown in fig. 4 and 5, the thermoelectric device 1 further includes: a thermoelectric unit 30 disposed between the hot side substrate 10 and the cold side substrate 20. The thermoelectric unit 30 includes: at least one first thermoelectric leg 31 and at least one second thermoelectric leg 32 connected in series by an end electrically conductive connection 33; two ends of each thermoelectric arm (31, 32) are respectively connected with different end conductive connecting pieces 33, and two adjacent thermoelectric arms are connected in series through the same end conductive connecting piece 33. In the thermoelectric unit 30, one of two adjacent thermoelectric legs connected in series is a first thermoelectric leg 31, and the other is a second thermoelectric leg 32.

That is, in the case where one first thermoelectric leg 31 and one second thermoelectric leg 32 are included in the thermoelectric unit 30, three end electrically conductive connections 33 are provided in the thermoelectric unit 30; one of the end conductive connectors 33 is connected between the first end of the first thermoelectric arm 31 and the first end of the second thermoelectric arm 32, and the other two end conductive connectors 33 are respectively connected with the second end of the first thermoelectric arm 31 and the second end of the second thermoelectric arm 32.

In the case where the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 are included in the thermoelectric unit 30, the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 are alternately connected in sequence by different end conductive connections 33, and both ends of the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 connected in series are connected to the other two end conductive connections 33, respectively.

In some possible implementations, the end conductive connector 33 may be made of a metal conductive material; such as copper, nickel or nickel alloys, etc.

The first thermoelectric leg 31 includes a first nanowire cluster S1 formed mainly of a P-type semiconductor thermoelectric material, and the second thermoelectric leg 32 includes a second nanowire cluster S2 formed mainly of an N-type semiconductor thermoelectric material.

Illustratively, in some possible implementation manners, the first nanowire cluster S1 may be obtained by performing P-type doping on a semiconductor such as silicon, a silicon germanium alloy, bismuth telluride, or the like as a body; the second nanowire cluster S2 can be obtained by N-type doping using a semiconductor such as silicon, silicon germanium alloy, bismuth telluride, or the like as a body.

It can be understood here that, in order to ensure that the first thermoelectric leg 31 and the second thermoelectric leg 32 in the thermoelectric unit 30 perform directional migration of carriers in the semiconductor thermoelectric material driven by the temperature difference between the heat source and the heat source to generate electric current, as shown in fig. 5, one of two end conductive connectors 33 connected to both ends of each thermoelectric leg (including 31, 32) is connected to the hot-side substrate 10, and the other is connected to the cold-side substrate 20. Illustratively, in some possible implementations, the hot-side substrate 10, the cold-side substrate 20, and the end conductive connector 33 may be connected by welding or bonding.

Compared with the single-layer thermoelectric structure formed by an etching process in the prior art, the semiconductor thermoelectric material of the present application adopts a nanowire cluster structure (i.e., a plurality of nanowires are arranged in parallel), so that the number of thermoelectric materials in a unit space (i.e., the space density of a power generation unit) can be increased spatially, and further, while the thermoelectric conversion efficiency of the thermoelectric device is increased, the output power of the thermoelectric device is increased, which is beneficial to increasing the power generation capacity of the thermoelectric device, and is beneficial to further expanding the application range of the thermoelectric device.

As shown in fig. 5, the nanowire clusters (including the first nanowire cluster S1 and the second nanowire cluster S2) in the thermoelectric unit 30 of the present application are disposed in parallel with the hot-side substrate 10 and the cold-side substrate 20, that is, the thermoelectric device 1 is a planar thermoelectric device; the nanowire clusters (including S1 and S2) in the thermoelectric unit 30 are not in direct contact with the hot-end substrate 10 and the cold-end substrate 20, i.e., the nanowire clusters are suspended; in this case, the hot-side substrate 10 and the cold-side substrate 20 do not disperse the heat flow passing through the nanowire clusters, so that the heat loss is reduced, and the thermoelectric conversion efficiency of the thermoelectric device is improved.

In addition, considering that the nanowire cluster (including S1 and S2) is composed of a plurality of nanowires which are not completely in the same plane and are arranged in parallel or approximately parallel, the strength of the nanowire (or the nanowire cluster) is small, and the nanowire cluster is easily damaged by external force. Illustratively, in some possible implementations, the single nanowire has a radius of about 10nm to about 100nm and a length of about 100nm to about 10 μm).

Based on this, as shown in fig. 4 and 5, in the thermoelectric device 1 of the present application, at the periphery of the thermoelectric unit 30, the supporting member 40 connected to both the hot side substrate 10 and the cold side substrate 20 is provided; effective strength support between hot junction base plate 10 and cold junction base plate 20 is realized through this support piece 40 for whole thermoelectric device possesses certain mechanical strength, thereby has guaranteed that the nanowire cluster is not taking place to damage because of external force under the condition of breaking away from the base plate.

The specific arrangement of the support member 40 in the present application is not particularly limited as long as the support member 40 can ensure effective strength support between the hot-side substrate 10 and the cold-side substrate 20.

In some possible implementations, as shown in fig. 6, the supports 40 may be disposed around the thermoelectric unit 30 in a dispersed manner.

In some possible implementations, to ensure that the support member 40, while ensuring effective strength support between the hot side substrate 10 and the cold side substrate 20, to ensure that the thermoelectric unit 30 is in a relatively closed space, isolates the convection of the nanowire clusters (including S1, S2) from the outside air, further reducing the heat loss of the nanowire clusters; as shown in fig. 4, the support member 40 may be provided as a sealed ring-shaped structure; and the supporting member is made of a material having a thermal conductivity of less than or equal to 1W/mK.

Illustratively, the low thermal conductivity material forming the support member 40 may include silicone or glass, etc.; the support member 40 may be fixed to an edge region between the hot end substrate 10 and the cold end substrate 20 by means of bonding.

Of course, it is understood that in the case of the support 40 having the sealed ring structure, for the traces of the thermoelectric device at the edge position, the sealed ring structure may be filled around the traces to ensure the insulation of the thermoelectric unit 30 from the external air.

In addition, in view of the short length of the single nanowire, in order to ensure that the thermoelectric arms (including 31, 32) form a sufficient separation distance between the cold side and the hot side to increase the hot path distance between the cold side and the hot side, in some possible implementations, the thermoelectric arms may be formed by a plurality of clusters of the same type doped nanowires connected in series by an intermediate conductive connector (also referred to as a cluster connector); thereby form better cold junction and hot junction and keep apart, effectively maintain the difference in temperature of cold junction and hot junction, and then improved thermoelectric device's thermoelectric conversion efficiency.

Schematically, as shown in fig. 7 and 8 (a cross-sectional view along position DD' of fig. 7), the first thermoelectric leg 31 may include a plurality of first nanowire clusters S1 connected in series by an intermediate conductive connection M; in fig. 7, the example that the first thermoelectric arm 31 includes 2 first nanowire clusters S1 is merely illustrated, but the present application is not limited thereto, and 3 or more first nanowire clusters S1 may be used.

It can be understood that the middle conductive connection member M serves as an electrical connection structure of the adjacent two first nanowire clusters S1. In some possible implementations, to avoid the intermediate conductive connector M from dispersing the heat flow through the nanowire clusters, as shown in fig. 8, the intermediate conductive connector M may be configured to be connected to the hot side substrate 10 or the cold side substrate 20 through the support connector Z; that is, the intermediate conductive connecting member M is not in direct contact with the hot-side substrate 10 or the cold-side substrate 20 (fig. 8 is only schematically illustrated by taking the example that the supporting connecting member Z is connected to the hot-side substrate 10), but is supported on the substrate (10 or 20) through the supporting connecting member Z, and the supporting connecting member Z is formed by a material having a thermal conductivity of less than or equal to 1W/mK.

Illustratively, in some possible implementations, the material forming the support connection Z may be silicon gel or glass.

Similarly, as shown in fig. 7 and 8, the second thermoelectric leg 32 may include a plurality of second nanowire clusters S2 connected in series by intermediate electrically conductive connections M; and the intermediate conductive connector M is connected to the hot-side substrate 10 or the cold-side substrate 20 through a support connector Z formed of a material having a thermal conductivity of 1W/mK or less.

In addition, the number of the first thermoelectric legs 31 and the second thermoelectric legs 32 in the thermoelectric unit 30 is not particularly limited in the present application. For example, a first thermoelectric leg 31 and a second thermoelectric leg 32 may be provided; two or more first thermoelectric legs 31 and two or more second thermoelectric legs 32 may be provided; in practice, considering that the thermoelectric devices continuously use electricity under different powers, the thermoelectric devices can be set according to the needs, and more than two first thermoelectric arms 31 and more than two second thermoelectric arms 32 can be arranged in the thermoelectric unit 30 to ensure that the output voltage of the thermoelectric device can meet the load of the thermoelectric devices; the following examples are all described by way of example.

It will be appreciated that the two end electrically conductive connections (33_1, 33_2) at the two ends of the thermoelectric element 30, one as the positive pole of the thermoelectric device and the other as the negative pole of the thermoelectric device; in practice, to simplify the connection between the positive and negative electrodes of the thermoelectric device and other devices in the thermoelectric device, as shown in fig. 4 and 9, two end conductive connectors (33_1, 33_2) may be disposed on the same side of the first plurality of thermoelectric legs 31 and the second plurality of thermoelectric legs 32 distributed in the thermoelectric unit 30, and both end conductive connectors (33_1, 33_2) are connected to one of the hot side substrate 10 or the cold side substrate 20.

In addition, the method for preparing the nanowire cluster (including S1 and S2) is not particularly limited, and in practice, the nanowire cluster may be prepared by selecting an appropriate preparation process according to the need. For example, in some possible implementations, Chemical Vapor Deposition (CVD) may be used, but is not limited thereto.

Illustratively, for the first nanowire cluster S1 consisting essentially of a P-type semiconductor thermoelectric material, Silane (SiH) may be used₄) As a silicon source, borane (B)₂H₆) As doping gas, gold (Au) as catalyst; silane gas and borane gas are continuously accumulated on the surface of the catalyst, grow and precipitate when the concentration reaches a certain degree, form a solid state of a silicon-based material, push the catalyst to continuously move along the growth, promote the growth of a new round, repeat the above steps, and finally inject gas to be converted into a solid along a single direction due to the moving traction of the catalyst in the single direction, so as to finally form a nanowire mainly made of a P-type semiconductor thermoelectric material; and simultaneously, a plurality of catalysts are adopted, so that the first nanowire cluster S1 formed by a plurality of nanowires can be prepared.

Similarly, for the second nanowire cluster S2 mainly composed of the N-type semiconductor thermoelectric material, Silane (SiH) may be used₄) As a silicon source, Phosphane (PH)₃) As a doping gas, and gold (Au) as a catalyst, a second nanowire cluster S2 formed of a plurality of nanowires is prepared.

Schematically, referring to fig. 4, in some embodiments, the first thermoelectric leg 31 includes a first nanowire cluster S1 connected between two end conductive connectors 33, in which case, two ends of the first nanowire cluster S1 are directly connected to the end conductive connectors 33, and when the first nanowire cluster is prepared, the first surface of one end conductive connector 33 (i.e., the surface facing the other end conductive connector 33) may be used as a substrate, and the first nanowire cluster 31 is formed by continuously growing from the first surface of the end conductive connector 33 to the surface of the other end conductive connector 33 by using a chemical vapor deposition method; i.e. the first nanowire cluster 31 is grown connected between two opposite sides of two end conductive connections 33.

Similarly, in the case where the second thermoelectric leg 32 includes one second nanowire cluster S2 connected between the two end electrically conductive connections 33, the second nanowire cluster 32 is grown connected between the two opposite sides of the two end electrically conductive connections 33.

Schematically, referring to fig. 7, in the case that the first thermoelectric leg 31 includes two first nanowire clusters S1 connected between two end conductive connectors 33 and connected in series through an intermediate conductive connector M, taking the preparation of the left first nanowire cluster S1 as an example, the first surface of the left end conductive connector 33 facing to the intermediate conductive connector M may be used as a substrate, and the first nanowire cluster 31 may be formed by continuously growing from the first surface of the end conductive connector 33 to the surface of the intermediate conductive connector M by using a chemical vapor deposition method; that is, the first nanowire cluster S1 on the left side is grown between the opposite sides of the end conductive connection 33 and the middle conductive connection M on the left side; the same is true for the preparation of the first nanowire cluster S1 on the right, i.e., the first nanowire cluster S1 on the right is grown and connected between the opposite sides of the end conductive connection 33 and the middle conductive connection M on the right.

Similarly, in the case where the second thermoelectric leg 32 comprises two second nanowire clusters S2 connected between the two end electrically conductive connections 33 and in series via the middle electrically conductive connection M, two second nanowire clusters S2 are respectively grown connected between the middle electrically conductive connection M and the opposite sides of the two end electrically conductive connections 33.

Of course, in the case where the first thermoelectric leg 31 includes three or more first nanowire clusters S1 connected between the two end conductive connectors 33 and connected in series via the plurality of middle conductive connectors M, as described above, the first nanowire cluster S1 connected between the end conductive connectors 33 and the middle conductive connectors M may be provided, and the first nanowire cluster S1 connected between the two middle conductive connectors M may be in a growth connection manner.

In the present application, the distribution form of the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 alternately connected in series in sequence in the thermoelectric unit 30 is not limited, and the distribution of the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 may be actually set according to the power demand and the shape, size, etc. of the substrates (including 10 and 20).

Illustratively, in some possible implementations, as shown in fig. 4, the first thermoelectric arms 31 and the second thermoelectric arms 32 alternately connected in series in sequence in the thermoelectric unit 30 may be distributed in two rows and two columns (fig. 4 is only schematically illustrated by the example that the first thermoelectric arms 31 and the second thermoelectric arms 32 are distributed in two rows and two columns, and the application is not limited thereto).

In this thermoelectric unit 30, the first nanowire cluster S1 in the first thermoelectric leg 31 and the second nanowire cluster S2 in the second thermoelectric leg 32 both extend in the row direction; the two thermoelectric legs in the same row are a first thermoelectric leg 31 and a second thermoelectric leg 32, i.e. the two thermoelectric legs in the same row are of different types; two adjacent thermoelectric legs in the same column are a first thermoelectric leg 31 and a second thermoelectric leg 32. In addition, the plurality of first thermoelectric legs 31 and the plurality of second thermoelectric legs 32 located in the same column are alternately arranged in series in turn by the end conductive connection member 33; the two thermoelectric legs in the first or last row are connected in series by an end electrically conductive connection. In this case, it can be understood that two thermoelectric legs located in the same row and connected, and two end electrically conductive connections (33_1, 33_2) located at both ends of the thermoelectric unit 30 are distributed on opposite sides of the thermoelectric unit 30.

In some possible implementations, as shown in fig. 4, the end conductive connectors 33 connected to both ends of each thermoelectric arm (31, 32) are distributed at both ends of the thermoelectric arm in the row direction (i.e., the extending direction of the thermoelectric arm); that is, the end conductive connecting pieces 33 connected with both ends of each thermoelectric arm (31, 32) are distributed on the left and right sides of each thermoelectric arm in the row direction; the end conductive connections 33 on the left and right sides of the thermoelectric legs in different rows of the same column may be aligned.

It should be noted that fig. 4 is only schematic, and the first thermoelectric arms 31 and the second thermoelectric arms 32 are distributed in six rows and two columns for example, in some other possible implementation manners, the first thermoelectric arms 31 and the second thermoelectric arms 32 in the thermoelectric unit 30 are alternately connected in series in sequence, and may also adopt other matrix arrangements, for example, eight rows and four columns, six rows and six columns, and the like.

It is understood herein that, in the case where the plurality of first thermoelectric arms 31 and the plurality of second thermoelectric arms 32 are alternately connected in series in sequence in the thermoelectric unit 30 and arranged in a matrix, the outer contour of the thermoelectric unit 30 is rectangular as a whole. Based on this, the shapes of the hot side substrate 10 and the cold side substrate 20 in the thermoelectric device may be correspondingly set to be rectangular, but are not limited thereto, and may be set to be other shapes as long as the setting of the thermoelectric unit 30 is satisfied.

Illustratively, in some possible implementations, as shown in fig. 9, the first plurality of thermoelectric arms 31 and the second plurality of thermoelectric arms 32 are alternately connected in series in sequence in the thermoelectric unit 30 and are uniformly distributed along a circumference of the first ring. The extending direction of the first nanowire cluster S1 in the first thermoelectric arm 31 and the second nanowire cluster S2 in the second thermoelectric arm 32 is consistent with the radius direction of the first circular ring; it is understood that the first ring is not a ring of a solid structure, but is merely an artificially configured arrangement of the first thermoelectric arm 31 and the second thermoelectric arm 32.

In addition, as for the uniform distribution of the plurality of first thermoelectric arms 31 and the plurality of second thermoelectric arms 32 along the circumference of the first ring, the middle points of the plurality of first thermoelectric arms 31 and the plurality of second thermoelectric arms 32 can be considered to be uniformly distributed along the circumference of the first ring; in practice, the first thermoelectric leg 31 and the second thermoelectric leg 32 may be configured to have substantially the same shape and size.

In some possible implementations, as shown in fig. 9, the end conductive connectors 33 connected to both ends of each thermoelectric arm (31, 32) are distributed at both ends of the thermoelectric arm along the radial direction of the first ring (i.e. the extending direction of the thermoelectric arm); that is, the end conductive connection members 33 connected to the respective thermoelectric legs (31, 32) are respectively distributed on the circular ring formed at the outer end of the thermoelectric leg and the circular ring formed at the inner end of the thermoelectric leg.

It is understood that, in the case where the plurality of first thermoelectric arms 31 and the plurality of second thermoelectric arms 32 are arranged in the ring form in the thermoelectric unit 30 in sequence and alternately in series, the outer contour of the thermoelectric unit 30 is generally circular. Based on this, the shapes of the hot end substrate 10 and the cold end substrate 20 in the thermoelectric device may be correspondingly set to be circular (especially suitable for current wearable devices, such as smart watches, etc.), but are not limited thereto, and may be set to be other shapes as long as the setting of the thermoelectric unit 30 is satisfied.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The thermoelectric device is characterized by comprising a hot end substrate and a cold end substrate which are oppositely arranged; the thermoelectric device further includes: a thermoelectric unit and a support member disposed between the hot side substrate and the cold side substrate;

the thermoelectric unit includes: at least one first thermoelectric leg and at least one second thermoelectric leg in series; the two ends of the first thermoelectric arm and the second thermoelectric arm are connected with different end conductive connecting pieces, and the ends of the two thermoelectric arms connected in series are connected through the same end conductive connecting piece; any two adjacent thermoelectric arms in series, one of which is the first thermoelectric arm, and the other of which is the second thermoelectric arm;

the first thermoelectric arm comprises a first nanowire cluster formed primarily of a P-type semiconductor thermoelectric material, and the second thermoelectric arm comprises a second nanowire cluster formed primarily of an N-type semiconductor thermoelectric material;

one of the two end conductive connecting pieces connected with the two ends of the first thermoelectric arm and the second thermoelectric arm is connected with the hot end substrate, and the other end conductive connecting piece is connected with the cold end substrate;

the first nanowire cluster and the second nanowire cluster are not in direct contact with the hot end substrate and the cold end substrate; the first nanowire cluster and the second nanowire cluster are arranged in parallel with the hot end substrate and the cold end substrate;

the support pieces are located on the periphery of the thermoelectric unit, and the support pieces are connected with the hot end substrate and the cold end substrate.

2. The thermoelectric device as claimed in claim 1, wherein the support is a sealed ring structure; the supporting piece is made of a material with a thermal conductivity coefficient smaller than or equal to 1W/mK.

3. The thermoelectric device as claimed in claim 1 or 2, wherein said first thermoelectric arm comprises a plurality of said first nanowire clusters connected in series by an intermediate electrically conductive connection;

and/or, the second thermoelectric arm comprises a plurality of the second nanowire clusters connected in series by an intermediate electrically conductive connection;

the middle conductive connecting piece is connected with the hot end substrate or the cold end substrate through a supporting connecting piece;

the supporting and connecting piece is made of a material with the thermal conductivity coefficient less than or equal to 1W/mK.

4. The thermoelectric device according to any one of claims 1 to 3,

said first thermoelectric leg comprising one said first nanowire cluster connected between two said end conductive connections, said first nanowire cluster being growth connected between two opposing sides of two said end conductive connections;

or the first thermoelectric arm comprises two first nanowire clusters which are connected between the two end conductive connecting pieces and are connected in series through a middle conductive connecting piece, and the two first nanowire clusters are respectively connected between opposite side surfaces of the middle conductive connecting piece and the two end conductive connecting pieces in a growing mode;

said second thermoelectric leg comprising one said second nanowire cluster connected between two said end conductive connections, said second nanowire cluster being growth connected between opposing sides of two said end conductive connections;

or the second thermoelectric arm comprises two second nanowire clusters which are connected between the two end conductive connecting pieces and are connected in series through a middle conductive connecting piece, and the two second nanowire clusters are respectively connected between the middle conductive connecting piece and the opposite side faces of the two end conductive connecting pieces in a growing mode.

5. The thermoelectric device according to any one of claims 1 to 4,

the thermoelectric unit comprises a plurality of the first thermoelectric legs and a plurality of the second thermoelectric legs;

the two end conductive connecting pieces connected with two ends of the thermoelectric unit are arranged on the same side of the first thermoelectric arms and the second thermoelectric arms;

and the two end conductive connecting pieces connected with the two ends of the thermoelectric unit are connected with one of the hot end substrate and the cold end substrate.

6. The thermoelectric device as claimed in any one of claims 1 to 5, wherein the thermoelectric unit comprises a plurality of the first thermoelectric legs and a plurality of the second thermoelectric legs alternately connected in series in sequence by the end conductive connection, and the plurality of the first thermoelectric legs and the plurality of the second thermoelectric legs are distributed in two rows and two columns; wherein the first nanowire cluster and the second nanowire cluster both extend in a row direction;

one of the two thermoelectric arms in the same row is the first thermoelectric arm, and the other one is the second thermoelectric arm;

the plurality of thermoelectric arms positioned in the same column are sequentially and alternately connected in series through the end conductive connecting piece, and the two thermoelectric arms positioned in the first row or the last row are connected in series through the end conductive connecting piece;

end conductive connecting pieces connected with two ends of each thermoelectric arm are distributed at two ends of each thermoelectric arm along the extending direction of the thermoelectric arms.

7. The thermoelectric device as recited in claim 6 wherein the hot side substrate and the cold side substrate are both rectangular.

8. The thermoelectric device according to any one of claims 1 to 5,

the thermoelectric unit comprises a plurality of first thermoelectric arms and a plurality of second thermoelectric arms which are sequentially and alternately connected in series through the end conductive connecting piece, and the plurality of first thermoelectric arms and the plurality of second thermoelectric arms are uniformly distributed along the circumference of the first circular ring; wherein the extending direction of the first nanowire cluster and the second nanowire cluster is consistent with the radius direction of the first circular ring;

and the end part conductive connecting pieces connected with the two ends of each thermoelectric arm are distributed at the two ends of the thermoelectric arm along the extending direction of the thermoelectric arm.

9. The thermoelectric device as recited in claim 8 wherein the hot side substrate and the cold side substrate are both circular.

10. The thermoelectric device as claimed in any one of claims 1 to 9 wherein said hot side substrate and said cold side substrate are metallized ceramic substrates.

11. The thermoelectric device as claimed in any of claims 1 to 10, wherein the material used for the support and/or the support connection comprises silica gel or glass.

12. A thermoelectric device comprising the thermoelectric device of any one of claims 1 to 11, an electric energy conversion system, and a load; the thermoelectric device is connected with the load through the electric energy conversion system.

13. The thermoelectric device of claim 12, wherein the thermoelectric device is a wearable device.