CN114050198A

CN114050198A - Radiation heat flow regulation and control device based on semiconductor material and application thereof

Info

Publication number: CN114050198A
Application number: CN202111160015.0A
Authority: CN
Inventors: 宋柏; 陈群; 李启章
Original assignee: Tsinghua University; Peking University
Current assignee: Tsinghua University; Peking University
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-02-15
Anticipated expiration: 2041-09-30
Also published as: CN114050198B

Abstract

The invention relates to a radiation heat flow regulation and control device based on semiconductor materials and application thereof, wherein the radiation heat flow regulation and control device comprises a first radiator and a second radiator which are oppositely arranged, the first radiator is provided with a semiconductor material layer, the semiconductor material layer contains intrinsic semiconductor materials and the doping concentration of carriers is less than 10¹⁶cm^‑3One or both of the doped semiconductor materials of (a); the first radiator is arranged in a suspended mode, or the first radiator comprises a first substrate containing a metal material layer. The technical scheme of the invention mainly utilizes the change of the local electromagnetic density of state caused by the change of the carrier concentration in the semiconductor material along with the temperature to realize the large-amplitude regulation and control of the radiant heat flow. The radiation heat flow regulation and control device provided by the invention can realize the functions of a thermal diode, a thermal triode, a thermal switch and the like by changing a trigger mechanism or combining with other components.

Description

Radiation heat flow regulation and control device based on semiconductor material and application thereof

Technical Field

The invention relates to the technical field of thermal radiation, in particular to a radiation heat flow regulation and control device based on a semiconductor material and application thereof.

Background

Heat transfer is one of the most basic physical phenomena in nature, and is widely used in scientific research and production life. More than 90% of global energy production is related to heat, so that effective regulation and control of the heat transfer process are of great importance to the development of novel thermal devices, the development of advanced heat management technologies, the improvement of energy utilization efficiency and the like. People's daily life is closely related to heat, ranging from wearing clothes to keep warm, cooking with water, indoor temperature control and air conditioning in vehicles, covering clothes, food, live and go. The continuous development of the regulation and control technology of heat transfer is expected to further improve the living standard of people.

The nonlinear electrical element can realize flexible regulation and control of current, is a cornerstone of modern electronic information technology mansion, and also thoroughly changes the life of people. However, the regulation of heat flow is much more difficult, the research on nonlinear thermal devices capable of flexibly regulating heat flow is not mature, and the research on heat transfer mechanism and the effective regulation of heat transfer process have important significance on scientific research and technical application in the thermal field.

Thermal radiation is one of three basic heat transport mechanisms, and is essentially electromagnetic waves induced by random thermal motion of charges in an object, including propagating waves and evanescent waves. These electromagnetic waves can be classified into electromagnetic waves of a propagation mode, a frustrated mode, and a surface mode according to their propagation characteristics. Wherein the amplitude of the evanescent wave decays exponentially with distance from the surface of the object. When the distance between the radiators is close to or less than the thermal characteristic wavelength, evanescent waves gradually participate in even dominant radiation heat exchange, the classical heat radiation law is broken, and the phenomenon is called near-field heat radiation.

The heat flow regulation device based on near-field thermal radiation usually has two ends, namely radiators on two sides, and the heat flow is transmitted between the two radiators in the form of electromagnetic waves. The thermal rectification based on the near-field thermal radiation can realize the regulation and control of heat flow by utilizing richer electromagnetic modes, is expected to realize larger regulation and control capability, and has attracted extensive attention in various nonlinear thermal devices such as thermal diodes, thermal triodes, thermal switches and the like.

The physical mechanisms behind different nonlinear thermal devices such as thermal diodes, thermal triodes and thermal switches are similar, and in near-field thermal radiation, the following can be concluded: different electromagnetic waves in the near-field thermal radiation are regulated and controlled through different triggering mechanisms such as heat, light, electricity and the like, so that the purpose of changing the size of the radiation heat flow is achieved. Taking a thermal diode as an example, a thermal diode based on a thermal rectification effect is a very typical heat flow regulation manner, and the magnitude of heat flow in a thermal rectification device is related to the bias direction of temperature under the same temperature difference. When the temperature direction changes, the change of the dielectric constant will cause the radiant heat flow to generate difference, thereby forming thermal rectification. The core performance parameter of thermal rectification is the rectification ratio, which is defined as the ratio of the difference between the forward and reverse heat flows to the smaller reverse heat flow.

In summary, in order to better realize the regulation in the heat transportation process, those skilled in the art hope to develop a new technical scheme to effectively improve the heat flow regulation capability of the near-field radiation heat flow regulation device.

Disclosure of Invention

The invention aims to provide a radiation heat flow regulation and control device based on a semiconductor material and application thereof. The radiation heat flow regulation and control device can realize functions of thermal rectification, thermal triodes, thermal switches and the like by changing a trigger mechanism or combining with other components.

To this end, in a first aspect, the present invention provides a radiation heat flow regulating device based on a semiconductor material, which includes a first radiator and a second radiator oppositely disposed;

the first radiator is provided with a semiconductor material layer which contains an intrinsic semiconductor material and has a carrier doping concentration less than 10¹⁶cm^-3One or both of the doped semiconductor materials of (a);

the first radiator is arranged according to one of the following modes (a), (b) and (c):

(a) the first radiator is formed by the semiconductor material layer and is arranged in a suspended mode;

(b) the first radiator also comprises a first substrate, the first substrate is made of non-metal materials, the semiconductor material layer covers the first substrate, and the first radiator is arranged in a suspended mode;

(c) the first radiator further comprises a first substrate, the first substrate comprises a first metal material layer, and the semiconductor material layer covers the first substrate.

Further, the distance between the first radiator and the second radiator is 1nm to 10mm, preferably 10nm to 100 μm, and more preferably 10nm to 1 μm. For example, the first radiator and the second radiator may have a pitch of 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, etc.

Further, in the semiconductor material layer, the volume ratio of the semiconductor material is 30-100% (V/V); preferably, the semiconducting material is present as a regularly or irregularly distributed discrete component, or the semiconducting material layer contains a regularly or irregularly distributed component of a non-semiconducting material.

In some embodiments, the semiconductor material layer is made of an intrinsic semiconductor material and has a carrier doping concentration of less than 10¹⁶cm^-3Of one or both of the doped semiconductor materials of (a).

In some embodiments, the volume of the semiconductor material in the semiconductor material layer is greater than or equal to 30% and less than 100%; preferably, the semiconducting material is present as a regularly or irregularly distributed discrete component, or the semiconducting material layer contains a regularly or irregularly distributed component of a non-semiconducting material.

Further, in the semiconductor material layer, the semiconductor is selected from one or a combination of two or more of the following groups: silicon (Si), germanium (Ge), gallium phosphide (GaP), gallium arsenide (GaAs), indium arsenide (InAs), boron (B), tellurium (Te), selenium (Se), gallium nitride (GaN), indium nitride (InN), aluminum nitride (AlN), aluminum oxide (Al)₂O₃) Silicon carbide (SiC), zinc oxide (ZnO), silicon nitride (Si)₃N₄) Gallium antimonide (GaSb), zinc sulfide (ZnS), cadmium telluride (CdTe), mercury telluride (HgTe), cuprous bromide (CuBr), cuprous iodide (CuI), bismuth telluride (Bi)₂Te₃) Bismuth selenide (Bi)₂Se₃) Bismuth sulfide (Bi)₂S₃) Arsenic telluride (As)₂Te₃) (ii) a Preferably silicon (Si), germanium (Ge), gallium phosphide (GaP), gallium arsenide (GaAs), indium arsenide (InAs), or the like.

Further, the thickness of the semiconductor material layer is 1nm-100mm, preferably 1nm-1mm, and more preferably 1nm-100 μm; for example, 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, etc.

According to the radiation heat flow regulation and control device provided by the invention, when the temperature changes, the carrier concentration of the semiconductor material layer in the first radiator is caused to be changed violently, so that the intensity of a high-kappa mode in a low-frequency region is caused to be changed sharply, and the key factor that the radiation heat flow regulation and control device can realize excellent heat rectification performance is provided. While the intensity of the low-k modes in the high frequency region hardly changes with temperature because these electromagnetic modes are mainly affected by the real part of the dielectric constant epsilon 'of the semiconductor material layer, and epsilon' hardly changes with temperature, and thus these low-k modes have a great negative influence on the performance of thermal rectification. Preferably, when the thickness of the semiconductor material layer is 1nm-1mm, the low-k modes are obviously weakened, and the high-k modes in the low-frequency range are hardly influenced, so that the thermal rectification performance of the radiation heat flow regulation device can be obviously improved.

Further, the first substrate has a thickness of 1nm to 100mm, for example, 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, and the like.

In some embodiments, the first radiator comprises a layer of semiconductor material and a first substrate composed of a non-metallic material, the first substrate having a thickness of 1nm to 1 μm, such as 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, and the like.

Further, the non-metallic material is preferably a polar material.

In some embodiments, the first radiator includes a semiconductor material layer and a first substrate, the semiconductor material layer covers the first substrate, and the first substrate includes a first metal material layer; in the first metal material layer, the volume ratio of the metal material is more than 20% (V/V); preferably, the thickness of the first metallic material layer is 1nm to 100mm, such as 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, and the like;

preferably, the distance from the midpoint of a vertical line between the first radiator and the second radiator to the first metal material layer is 10nm-100 mm; for example, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, etc.

In some embodiments, the first metallic material layer is composed of a metallic material.

In some embodiments, the first substrate is comprised of a first layer of metallic material.

In other embodiments, the first substrate comprises a first layer of metallic material and a layer of non-metallic material; the non-metallic material is preferably a polar material.

Further, the second radiator is provided with one or a combination of two of a polar material layer and a doped semiconductor material layer.

Further, in the polar material layer, the volume ratio of the polar material is 30-100% (V/V); preferably, the polar material is present as a regularly or irregularly distributed discrete component, or the layer of polar material contains a regularly or irregularly distributed component of a non-polar material.

In some embodiments, the polar material layer is composed of a polar material.

In some embodiments, the polar material layer has a volume fraction of polar material of 30% or more and less than 100%; preferably, the polar material is present as a regularly or irregularly distributed discrete component, or the layer of polar material contains a regularly or irregularly distributed component of a non-polar material.

Further, the polar material is selected from sodium chloride (NaCl), potassium bromide (KBr), potassium chloride (KCl), barium fluoride (BaF)₂) Cesium fluoride (SrF)₂) Calcium fluoride (CaF)₂) Lithium fluoride (LiF), gallium nitride (GaN), magnesium oxide (MgO), cesium bromide (CsBr), cesium iodide (CsI), zinc sulfide (ZnS), silver bromide (AgBr), silver chloride (AgCl), cubic boron nitride (cBN), silicon carbide (SiC), silicon dioxide (SiO), silicon nitride (SiC), and the like₂) Hexagonal boron nitride (hBN), zinc selenide (ZnSe), sapphire, cadmium telluride (CdTe), silicon dioxide (SiO)₂) Etc.; preferably sodium chloride (NaCl), potassium bromide (KBr), potassium chloride (KCl), barium fluoride (BaF)₂) Cesium fluoride (SrF)₂) Calcium fluoride (CaF)₂) Lithium fluoride (LiF), gallium nitride (GaN), magnesium oxide (MgO), cesium bromide (CsBr), cesium iodide (CsI), zinc sulfide (ZnS), silver bromide (AgBr), or silver chloride (AgCl).

Further, the thickness of the polar material layer is 1nm-100mm, preferably 1nm-10 mm; for example, 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, etc.

Further, the doping concentration of the doped semiconductor layer is more than 10¹⁵cm^-3Doped semiconductor material of (a); preferably, the doping concentration is 10¹⁵-10²⁰cm^-3(ii) a More preferably, the doping concentration is 10¹⁶-10²⁰cm^-3(ii) a Further preferably, the doping concentration is 10¹⁷-10¹⁹cm^-3(ii) a Wherein the semiconductor is selected from silicon (Si), germanium (Ge), gallium phosphide (GaP), gallium arsenide (GaAs), indium arsenide (InAs), boron (B), tellurium (Te), selenium (Se), gallium nitride (GaN), indium nitride (InN), aluminum nitride (AlN), aluminum oxide (Al)₂O₃) Silicon carbide (SiC), zinc oxide (ZnO), silicon nitride (Si)₃N₄) Gallium antimonide (GaSb), zinc sulfide (ZnS), cadmium telluride (CdTe), mercury telluride (HgTe), cuprous bromide (CuBr), cuprous iodide (CuI), bismuth telluride (Bi)₂Te₃) Bismuth selenide (Bi)₂Se₃) Bismuth sulfide (Bi)₂S₃) Arsenic telluride (As)₂Te₃) (ii) a Preferably silicon (Si), germanium (Ge), gallium phosphide (GaP), gallium arsenide (GaAs) or indium arsenide (InAs).

The thickness of the doped semiconductor layer is 1nm-100mm, preferably 1nm-10 mm; for example, 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, etc.

Further, the second radiator further comprises a second substrate, the polar material layer or the doped semiconductor material layer covers the second substrate, and the second substrate comprises a metal material layer; in the metal material layer, the volume ratio of the metal material is more than 20% (V/V);

preferably, the thickness of the second metallic material layer is 1nm to 100mm, such as 1nm, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, and the like;

preferably, the distance of the midpoint of the vertical line between the first radiator and the second radiator from the second metallic material layer is 10nm to 100mm, for example, 10nm, 20nm, 50nm, 80nm, 100nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 100 μm, 500 μm, 1mm, 2mm, 5mm, 10mm, 50mm, 100mm, and the like.

According to the radiant heat flow regulating device, when the radiant heat flow regulating device comprises a substrate containing a metal material layer, the distance between the midpoint of a vertical line between the first radiator and the second radiator and the metal material layer is 10nm-100 mm. In the research of the invention, it is found that if the metal material layer is too close (for example, less than 10nm), more radiation heat flows can be contributed, and the heat flows are not sensitive to the change of the temperature bias direction (because the dielectric constant of the metal is not sensitive to the temperature change), so that the heat flow regulation performance can be weakened; too far (e.g., greater than 100mm) of the metal layer means a larger volume of radiator above the metal layer, resulting in more low- κ modes, which also impairs heat flow regulation.

In some embodiments, the second metallic material layer is composed of a metallic material.

In some embodiments, the second substrate is comprised of a second layer of metallic material.

In other embodiments, the second substrate comprises a second layer of metallic material and a layer of non-metallic material; the non-metallic material is preferably a polar material.

Further, the metal material is selected from one or a combination of two or more of the following groups: silver (Ag), gold (Au), and aluminum (Al).

According to the radiation heat flow regulation and control device, the first substrate and the second substrate are mainly used for supporting and improving the mechanical strength of the device, the metal material layer is mainly used for shielding heat radiation on the back surface of the device, and when the thickness of the metal material layer is larger than or equal to 10nm, effective shielding can be achieved; when the thickness of the metal material layer is more than or equal to 100nm, high-efficiency shielding can be realized; when the thickness of the metal material layer is more than or equal to 1000nm, nearly complete shielding can be realized, and the radiation heat flow regulation and control device is placed on any object without influencing the heat flow regulation and control performance of the device. Even if the thickness of the metal material layer is only 1nm, a certain shielding effect can be achieved. The thickness of the layer of metallic material can be chosen as appropriate for the actual situation between 10nm and 100mm, common thicknesses being for example between 100nm and 10 μm.

In some embodiments, the second radiator includes a doped semiconductor material layer, a polar material layer, and a second substrate that are sequentially stacked.

According to the radiation heat flow regulation device, if a covering layer with the thickness not more than 1 μm is additionally arranged on the surface of one side of the second radiator close to the first radiator (for example, a covering layer with pores or non-metal materials accounting for more than 20 percent of the total area is additionally arranged); and/or if a covering layer with a thickness not exceeding 1 μm is added to the surface of the first radiator on the side close to the second radiator (for example, a covering layer with pores or non-metallic material content > 20%) is still within the scope of the present invention.

The radiation heat flow regulating device according to the present invention at least includes a first radiator and a second radiator, and on this basis, the radiation heat flow regulating device may be provided with more radiators by stacking a plurality of first radiators and second radiators, which is also within the protection scope of the present invention.

In some embodiments, in the radiant heat flow regulating device, one or more radiators are further disposed between the first radiator and the second radiator.

In some embodiments, in the radiation heat flow regulation device, one or more first radiators and/or second radiators are further disposed between the first radiator and the second radiator.

In a second aspect of the invention, there is provided a use of the radiant heat flow regulating device of the invention in heat flow regulation.

In a third aspect of the invention, a thermal current regulator comprising the radiant heat flow regulating device is provided.

Further, the thermal current regulator is a thermal diode, a thermal triode or a thermal switch.

Compared with the prior art, the invention has the following advantages:

the invention provides a radiation heat flow regulating device comprising a first radiator and a second radiator, wherein the first radiator comprises a semiconductor material layer, so that the first radiator can provide local electromagnetic state density difference as much as possible; the second radiator comprises a polar material layer and/or a doped semiconductor material layer, so that a proper frequency section can be selectively screened to dominate radiation heat exchange, and the local electromagnetic state density difference provided by the first radiator as much as possible can be converted into the difference of radiation heat flow, thereby realizing the efficient regulation and control of the radiation heat flow.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. In the drawings:

FIG. 1: schematic view of a thermal diode based on thermal radiation;

FIG. 2: the change rule of the real part and the imaginary part of the dielectric constant of the intrinsic silicon at different temperatures;

FIG. 3: local electromagnetic density of states of the intrinsic silicon of the semi-infinite planar structure at different temperatures;

FIG. 4: the local electromagnetic state density change proportion of the intrinsic silicon layer materials with different thicknesses; wherein, the change ratio of the local electromagnetic density of states is 1000K local electromagnetic density of states/300K local electromagnetic density of states;

FIG. 5: the change ratio of the local electromagnetic state density of the intrinsic silicon hollow thin film and the local electromagnetic state density of the polar material layer with the infinite plane structure; wherein, the change ratio of the local electromagnetic density of states is 1000K local electromagnetic density of states/300K local electromagnetic density of states;

FIG. 6: the local electromagnetic state density change proportion of the intrinsic silicon hollow thin film and the local electromagnetic state density of the doped silicon thin films with different thicknesses under 300K and 1000K respectively; wherein, the change ratio of the local electromagnetic density of states is 1000K local electromagnetic density of states/300K local electromagnetic density of states;

FIG. 7: the invention provides a structural schematic diagram of a first radiator of a radiation heat flow regulation device;

FIG. 8: the invention provides a structural schematic diagram of a second radiator of a radiation heat flow regulation device;

FIG. 9: another structure diagram of a second radiator of the radiation heat flow regulation device provided by the invention;

FIG. 10: the invention provides a structural schematic diagram of a thermal diode;

FIG. 11: the invention provides a structural schematic diagram of a thermal triode;

FIG. 12: under the condition of different radiator pitches, the change condition of the rectification ratio of the thermal diode provided by the invention is realized;

FIG. 13: a local electromagnetic density of state diagram of a first radiator made of intrinsic silicon under the condition of temperature variation;

FIG. 14: the change ratio of the local electromagnetic state density of the first radiator consisting of the intrinsic silicon and the silver; wherein, the change ratio of the local electromagnetic density of states is 1000K local electromagnetic density of states/300K local electromagnetic density of states;

FIG. 15: a radiation heat exchange coefficient diagram of a thermal diode combining intrinsic silicon and potassium bromide under the conditions of forward and reverse temperature bias respectively;

FIG. 16: the rectification ratio of the intrinsic silicon and potassium bromide combined thermal diode changes along with the thickness of the film;

FIG. 17: a radiation heat exchange coefficient diagram of a thermal diode formed by combining intrinsic silicon and doped silicon under the conditions of forward and reverse temperature bias respectively;

FIG. 18: the rectification ratio of the thermal diode formed by combining the intrinsic silicon and the doped silicon changes along with the thickness of the film;

FIG. 19: a schematic of a thermal diode comprising a combination of intrinsic silicon and potassium bromide of a substrate;

FIG. 20: the rectification ratio of the thermal diode combined by intrinsic silicon containing a substrate and potassium bromide changes along with the thickness of the film;

FIG. 21: a schematic structural diagram of a thermal diode comprising a combination of intrinsic silicon and doped silicon of a substrate;

FIG. 22: the rectification ratio of the thermal diode combined by intrinsic silicon and doped silicon containing a substrate changes along with the thickness of the film;

FIG. 23: a schematic of a thermal diode comprising a combination of intrinsic silicon, doped silicon and potassium bromide of the substrate;

FIG. 24: the rectification ratio of the thermal diode combined by intrinsic silicon containing a substrate, doped silicon and potassium bromide changes along with the thickness of the film;

FIG. 25: a schematic of a thermal diode comprising a non-metallic substrate of intrinsic silicon combined with cubic boron nitride.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Fig. 1 shows a schematic diagram of a thermal diode based on thermal radiation, which is a very typical way of regulating heat flow, and the magnitude of the heat flow in a thermal rectifier device is related to the bias direction of the temperature under the same temperature difference. When the temperature direction changes, the change of the dielectric constant will cause the radiant heat flow to generate difference, thereby forming thermal rectification. The core performance parameter of thermal rectification is the rectification ratio, which is defined as the ratio of the difference between the forward and reverse heat flows to the smaller reverse heat flow.

Based on the theory framework of wave electrodynamic theory, two parallel plane radiators-the first radiator (at T)₁At temperature) and a second radiator (at T)₂Temperature) can be calculated by the following equation:

where d is the spacing between two radiators, ω is the angular frequency, and κ is the transverse wavevector. For far-field thermal radiation at the macro scale, onlyWith transverse wave vector less than omega/c₀The electromagnetic wave participates in radiation heat exchange (c)₀Speed of light in vacuum); and when the distance between the two radiators is less than the thermal wavelength (about 10 μm at room temperature), the transverse wave vector κ is greater than ω/c₀The evanescent wave of (a) can start to participate in even dominant radiative heat exchange, especially when some electromagnetic modes (called high-kappa electromagnetic modes) with large transverse wave vectors kappa participate, the radiative heat exchange capacity can be enhanced by several orders of magnitude compared with far-field thermal radiation. Therefore, by making reasonable use of these high κ modes, efficient modulation of radiant heat flow is expected.

The invention provides the difference of the local electromagnetic density of state as much as possible by the first radiator, so that the near-field radiation heat flow regulation device has the heat flow regulation and control capability as much as possible. In addition, because the local electromagnetic density of state under different frequency bands is different, the invention selectively screens proper frequency bands by applying the second radiator to dominate the radiation heat exchange, thereby converting the local electromagnetic density of state provided by the first radiator as much as possible into the difference of radiation heat flow, and realizing the high-efficiency regulation and control of the radiation heat flow.

The local electromagnetic density of states is defined as the number of electromagnetic modes in a unit space and a unit frequency in a certain area above the radiator. For a planar radiator, the local electromagnetic density of states at its upper position z can be calculated using the following equation:

in the formula (2), r_s、r_pThe interface Fresnel reflection coefficients of s and p polarization states, k₀And gamma₀Respectively the transversal and longitudinal wave vectors (perpendicular to the interface) in vacuum. The local electromagnetic density of states is selected as the reference physical quantity because the local electromagnetic density of states can represent the near-field radiation capability of a radiator, and generally speaking, the larger the local electromagnetic density of states is, the larger the near-field radiation heat flow can be realized by the radiator.

From the above, one key point of realizing efficient thermal radiation regulation is to design a radiator to realize large change of local electromagnetic density under the control of external environment (such as temperature, electric field, magnetic field, pressure, etc.). In order to obtain as large a variation of local electromagnetic density of states as possible, the present invention uses a layered semiconductor material, which induces a large difference in local electromagnetic density of states by using a change in dielectric constant caused by a change in internal carriers. For a semiconductor material, its dielectric constant can be generally written as the following expression:

wherein ε 'and ε' are the real and imaginary parts of the dielectric constant, respectively_blRepresents contributions from internal interband transitions of the material and lattice absorption, N_e、

τ_eConcentration, equivalent mass and relaxation time, N, of electrons in the conduction band, respectively_h、

τ_hConcentration of holes in the valence band, equivalent mass and relaxation time, ε₀Is the dielectric constant in vacuum.

Taking the dielectric constant characteristics of semiconductor materials at different temperatures as an example, when the temperature rises, the concentration of free carriers increases due to thermal excitation, so that the imaginary part epsilon 'of the dielectric constant is remarkably increased, and the real part epsilon' of the dielectric constant is almost unchanged. Taking intrinsic silicon as an example, the change law of the real part and the imaginary part of the dielectric constant with temperature is shown in fig. 2; fig. 3 shows local electromagnetic density of states characteristic of semi-infinite large planar structured intrinsic silicon at different temperatures.

As can be seen from fig. 3, when the temperature of the intrinsic silicon of the semi-infinite planar structure is raised from 300K to 1000K, the local electromagnetic density of states in the low frequency range can be changed by more than 4 orders of magnitude at maximum. The cause of this diseaseDue to the emissivity of the high-k mode of the p-polarization state

It is the increase in these high κ modes that increases with increasing ε "that causes the local electromagnetic state density above the radiator to rise dramatically. Thus, it is known that temperature can induce an increase in the carrier concentration of a semiconductor, resulting in a characteristic change in its dielectric constant, and ultimately a significant difference in local electromagnetic state density.

In order to further improve the difference of the local electromagnetic density of state of the semiconductor layered material at different temperatures, the invention researches the local electromagnetic density of state of the semiconductor layered material with different thicknesses. The invention finds that the semiconductor material is thinned and suspended, so that the contribution of the electromagnetic wave with smaller transverse wave vector kappa to the heat radiation in the material can be reduced, and larger local electromagnetic state density difference can be obtained in a wider frequency range. Using intrinsic silicon as an example, fig. 4 shows the local electromagnetic density of state variation characteristics of intrinsic silicon layered material at different thicknesses.

In order to provide a first radiator with as large a local variation of the electromagnetic density of states as possible, in some embodiments of the invention the semiconductor material in the first radiator is intrinsic silicon; in other embodiments of the present invention, the semiconductor material in the first radiator is a low-doped semiconductor (with a carrier doping concentration less than 10)¹⁶cm^-3) When the low-doped semiconductor material is adopted, the change of the external environment (such as temperature, an electric field, a magnetic field, pressure and the like) is easier to generate larger carrier concentration change due to lower carrier concentration, so that larger local electromagnetic state density difference and corresponding radiation heat flow regulation and control capability are facilitated.

In order to make full use of and convert the local electromagnetic density of states difference of the layered semiconductor material in the first radiator into the difference of radiation heat flow, the invention provides a second radiator which is matched with the first radiator. In some embodiments of the present invention, the second radiator is a narrow band radiator, and is mainly made of polar material; in other embodiments of the present invention, the second radiator is a broadband radiator and is mainly composed of a doped semiconductor material.

In some embodiments of the present invention, the second radiator is a narrow band radiator, which is mainly characterized by supporting a peak of local electromagnetic state density in a narrow frequency band. In some embodiments, the second radiator comprises a polar material layer, and the polar material is selected from one or a combination of two or more of the following groups: sodium chloride (NaCl), potassium bromide (KBr), potassium chloride (KCl), barium fluoride (BaF)₂) Cesium fluoride (SrF)₂) Calcium fluoride (CaF)₂) Lithium fluoride (LiF), gallium nitride (GaN), magnesium oxide (MgO), cesium bromide (CsBr), cesium iodide (CsI), zinc sulfide (ZnS), silver bromide (AgBr), silver chloride (AgCl), cubic boron nitride (cBN), silicon carbide (SiC), silicon dioxide (SiO), silicon nitride (SiC), and the like₂) Hexagonal boron nitride (hBN), zinc selenide (ZnSe), sapphire, cadmium telluride (CdTe), silicon dioxide (SiO)₂) Etc.; preferably sodium chloride (NaCl), potassium bromide (KBr), potassium chloride (KCl), barium fluoride (BaF)₂) Cesium fluoride (SrF)₂) Calcium fluoride (CaF)₂) Lithium fluoride (LiF), gallium nitride (GaN), magnesium oxide (MgO), cesium bromide (CsBr), cesium iodide (CsI), zinc sulfide (ZnS), silver bromide (AgBr), silver chloride (AgCl).

The invention provides the polar material which can be used for the second radiator, and a frequency band with larger local electromagnetic density difference, which is constructed by the semiconductor laminar material, can be screened out by adopting a proper polar material, so that the effective regulation and control of radiation heat flow are realized.

By way of example, FIG. 5 shows five different polar materials, potassium bromide (KBr), potassium chloride (KCl), barium fluoride (BaF)₂) Silicon carbide (SiC), and cubic boron nitride (cBN), and shows the local electromagnetic density of states characteristic of such five polar material layers having a semi-infinite planar structure; for ease of comparison and comparison, the ratio of the local electromagnetic density of states of the intrinsic silicon voided film is also shown.

As can be seen from fig. 5, the five polar materials can form a very sharp peak of local electromagnetic density of states in a specific frequency band, and when the difference of the local electromagnetic density of states induced by the semiconductor layered material in the frequency band corresponding to the peak is larger, the radiation heat flow regulation capability that can be formed is larger. Therefore, for the intrinsic silicon thin film, the matching of the five materials can obtain greater radiation heat flow regulation capacity, and the matching of potassium bromide and the intrinsic silicon thin film is the best.

In some embodiments of the present invention, the second radiator is a broadband radiator, and is mainly characterized in that the second radiator can have a large local electromagnetic state density in a wide low-frequency range, and the local electromagnetic state density in the low-frequency range does not change significantly with changes in external environments (e.g., temperature, electric field, magnetic field, pressure, etc.). In some embodiments, the second radiator comprises a layer of doped semiconductor material having a carrier doping concentration greater than 10¹⁵cm^-3Because the concentration of the doped carriers is high, the local electromagnetic density of states is easy to change obviously along with the change of the external environment.

By way of example, doped silicon of different thicknesses (n-type doping, doping concentration 10) is shown in fig. 6¹⁸cm^-3) The local electromagnetic density of the film under 300K and 1000K respectively; for ease of comparison and comparison, the ratio of the local electromagnetic density of states of the intrinsic silicon voided film is also shown.

As can be seen from fig. 6, the semi-infinite planar structure doped silicon and the doped silicon thin films with different thicknesses can support a large local electromagnetic density in the low frequency range, so that the semiconductor layered material can fully utilize the large local electromagnetic density difference generated in the low frequency range. Meanwhile, as the doped silicon thin film becomes thinner, the local electromagnetic state density in a high-frequency region of the doped silicon thin film is continuously reduced, and the doped silicon thin film is thinned to weaken the electromagnetic wave with smaller transverse wave vector k transmitted in the doped silicon thin film, so that the change of a high-k electromagnetic mode leads the change of radiation heat flow, and more efficient heat flow regulation and control are realized.

In an embodiment, referring to fig. 7, the first radiator is disposed in one of the following three manners:

(a) the first radiator is composed of a semiconductor material layer and is arranged in a suspended mode;

(b) the first radiator comprises a semiconductor material layer and a first substrate, the first substrate is made of a non-metal material, the semiconductor material layer covers the first substrate, and the first radiator is arranged in a suspended mode;

(c) the first radiator comprises a semiconductor material layer and a first substrate, the first substrate comprises a first metal material layer, and the semiconductor material layer covers the first substrate.

In an embodiment, referring to fig. 8, the second radiator is disposed in one of the following three ways:

(a) the second radiator is composed of a polar material layer and is arranged in a suspended mode;

(b) the second radiator comprises a polar material layer and a second substrate, the second substrate is made of a non-metallic material, the polar material layer covers the second substrate, and the second radiator is arranged in a suspended mode;

(c) the second radiator comprises a polar material layer and a second substrate, the second substrate comprises a first metal material layer, and the polar material layer covers the second substrate.

In an embodiment, referring to fig. 9, the second radiator is disposed in one of the following two manners:

(a) the second radiator is formed by a doped semiconductor material layer and is arranged in a suspended mode;

(b) the second radiator comprises a doped semiconductor material layer and a second substrate, the second substrate is made of a non-metal material, the doped semiconductor material layer covers the second substrate, and the second radiator is arranged in a suspended mode;

(c) the second radiator comprises a doped semiconductor material layer and a second substrate, the second substrate comprises a first metal material layer, and the doped semiconductor material layer covers the second substrate.

In the present invention, an important factor for achieving large heat flow regulation performance is to weaken the contribution of low-k modes propagating inside the radiator, and these low-k modes are related to the volume of the radiator, and generally speaking, the larger the volume of the radiator, the more low-k modes, the worse the heat flow regulation performance. Therefore, the radiator employed in the present invention is set in one of the following ways: one of the two is to adopt a substrate containing a metal material layer, and the metal material layer has higher reflectivity and can shield the heat radiation of the back surface of the radiator, namely other materials on the back surface of the radiator cannot influence the radiation heat exchange, and the volume of the radiator for generating the low-k mode is only the volume of the radiator above the metal layer, so that the number of the low-k mode is effectively limited; if the substrate including the metal layer is not used, in order to avoid introducing too many low- κ patterns, the radiator cannot be too thick and needs to be installed in a floating manner (i.e. there is no other radiator on the back of the radiator). In practical use, the suspension mode can be a cantilever support mode.

According to the invention, when the semiconductor material layer covers the first substrate including the metal material layer, the first radiator may be in a suspended configuration or a non-suspended configuration, which is within the protection scope of the invention.

According to the present invention, the term "semiconductor material" includes both intrinsic semiconductor material and doped semiconductor material, which are generic concepts of both.

In a certain embodiment, the semiconductor material layer is comprised of a semiconductor material.

In one embodiment, the semiconductor material layer has a volume fraction of 30% to 100% (V/V), such as 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc.

In an embodiment, when the proportion of the semiconductor material is less than 100%, the portion other than the semiconductor material is a void or a non-metal material (e.g., a polar material).

In some embodiments, the semiconductor material layer is not completely made of a semiconductor material, which may be due to inevitable impurities introduced during the device manufacturing process, or due to voids in the semiconductor material layer or other non-semiconductor material filling for cost considerations, and such technical adjustments and improvements are within the scope of the present invention. For the technical scheme of the invention, when the volume of the semiconductor material in the semiconductor material layer is more than or equal to 30%, the large contribution can be formed to the local electromagnetic state density of the first radiator, so that the heat flow regulation and control performance is remarkably excellent.

The filled material can be a non-metal material, particularly a polar material, because the metal material can induce wide-spectrum surface plasmon polaritons which are not easy to regulate and control, so that the change of the local electromagnetic state density is weakened, and the polar material only has the surface phonon polaritons which are not easy to regulate and control in an extremely narrow frequency band and cannot generate large influence on the local electromagnetic state density in a wider frequency band, so that the first radiator can still form larger difference of the local electromagnetic state density.

In a certain embodiment, the polar material layer is composed of a polar material.

In one embodiment, the polar material layer has a volume ratio of 30% to 100% (V/V); e.g., 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, etc.

In one embodiment, the first substrate or the second substrate contains not only a metallic material layer but also a non-metallic material layer.

In one embodiment, the first substrate or the second substrate comprises a plurality of layers of metallic material and non-metallic material.

In one embodiment, referring to fig. 10, the radiation heat flow control device is a thermal diode having a first radiator and a second radiator oppositely disposed.

In an embodiment, referring to fig. 11, the radiant heat flow regulating device is a radiant heat triode, which includes a first radiator and two second radiators, and the first radiator is sandwiched between the two second radiators.

In one embodiment, the radiant heat flow regulating device (c)Denoted as i-Si-KBr in fig. 12) includes a first radiator made of an intrinsic silicon thin film having a thickness of 10nm and a second radiator made of a potassium bromide thin film having a thickness of 10 nm; in another embodiment, the radiation heat flow control device (i-Si-d-Si in fig. 12) includes a first radiator and a second radiator, the first radiator is composed of an intrinsic silicon thin film with a thickness of 10nm, and the second radiator is composed of doped silicon with a thickness of 10nm (doping concentration of 10nm)¹⁸cm^-3) A film. The calculation analysis shows the change of the rectification ratio when the distance between the two radiators is changed, and the result is shown in fig. 12. As can be seen from fig. 12, when the distance between two radiators is 1 μm, the rectification ratio can still reach more than three orders of magnitude.

Hereinafter, the radiation heat flow control device of the present invention is typically illustrated as a thermal diode, but this does not mean that the radiation heat flow control device of the present invention is limited to be used as a thermal diode, which can implement functions of a thermal triode, a thermal switch, etc. by changing a trigger mechanism or combining with other components.

Example 1

The embodiment provides a first radiator made of an intrinsic silicon material layer, and calculates and analyzes the local electromagnetic density of states at a position 100nm above the first radiator, wherein the relevant parameters include: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis result is shown in FIG. 13.

In fig. 13, (a) the intrinsic silicon material layer is a bulk material, which is equivalent to a semi-infinite plane in thermal radiation analysis; (d) the thickness of the intrinsic silicon material layer is 10 nm; in the figures below (a) (d), the local electromagnetic density of states of the intrinsic silicon material layer under temperature variation is shown, respectively. Each point in the graph corresponds to a particular frequency and local density of electromagnetic states of the transverse wave vector, with the brighter each point the greater the number of electromagnetic modes representing that mode.

In the radiation heat flow regulation device provided by the invention, the key for realizing heat rectification is that when the temperature bias direction is changed, the carrier concentration in the semiconductor material layer of the first radiator is changed violently, so that the intensity of a high-kappa mode in a low-frequency region is changed sharply. As can be seen from fig. 13, the intensity of the low- κ modes (electromagnetic modes that can propagate inside the intrinsic silicon material) in the high-frequency range hardly changes with temperature, because these electromagnetic modes are mainly affected by the real part of the dielectric constant of the intrinsic silicon ∈ ', and ∈' hardly changes with temperature, so these low- κ modes have a large negative effect on the performance of thermal rectification. After the semi-infinite intrinsic silicon bulk is changed into the empty intrinsic silicon thin film with limited thickness, the low-k modes are obviously weakened, and the high-k mode in the low-frequency region is hardly influenced, so that the thermal rectification performance is obviously improved.

Example 2

The present embodiment provides a first radiator made up of a layer of intrinsic silicon material and a first substrate made of silver. Calculating and analyzing the local electromagnetic state density at 10nm and 100nm above the first radiator, wherein the related parameters comprise: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis result is shown in FIG. 14.

Although a suspended film structure can be implemented (e.g., by means of a cantilever support, etc.), for easier processing and assembly, the present embodiment provides the first radiator with a substrate. In order to shield the influence of back radiation and simultaneously improve the mechanical strength of the device, a metal substrate with high reflectivity is arranged below the intrinsic silicon thin film. As can be seen from fig. 14, when a bulk (equivalent to a semi-infinite planar structure) silver substrate is added, a large difference in the local electromagnetic density of states can be formed in the low frequency region with a suitable thickness of the intrinsic silicon thin film.

According to the invention, calculation and analysis show that the metal layer in the substrate can also contribute to the local electromagnetic density of state above the radiator, and because the local electromagnetic density of state formed by the metal layer at different temperatures changes slightly, if the semiconductor material layer is too thin, the metal layer in the substrate is closer to the surface of the radiator, which can make the metal layer greatly contribute to the total local electromagnetic density of state, thereby reducing the difference of the local electromagnetic density of state above the semiconductor material layer at different temperatures, and being not beneficial to realizing large heat flow regulation performance. If too thick a layer of semiconductor material is used to space the metal layer from the surface of the emitter, more low- κ modes are introduced, which also does not facilitate radiant heat flow regulation. Therefore, according to the radiation heat flow regulating device provided by the present invention, when the first radiator comprises the first substrate including the metal layer, the thickness of the semiconductor material layer needs to be moderate (10nm-10mm), and cannot be too thin or too thick.

Example 3

The embodiment provides a radiation heat flow regulation device without a substrate, which comprises a first radiator and a second radiator, wherein the first radiator is made of intrinsic silicon materials, and the second radiator is made of potassium bromide materials; the first radiator is arranged in a suspension manner; the distance between the first radiator and the second radiator is 100 nm. The embodiment analyzes the thermal rectification performance of the radiation heat flow regulation device when the first radiator and the second radiator have different thicknesses.

The embodiment analyzes the thermal rectification performance of the radiation heat flow regulation device with the following three typical structures, and the related parameters comprise: the temperature of the high temperature end was 1000K, the temperature of the low temperature stage was 300K, and the analysis results are shown in Table 1 and FIG. 15.

Table 1 performance of thermal diodes based on different structures of intrinsic silicon and potassium bromide combination

In Table 1, the thickness of the thin film is 10nm, and the bulk indicates that the thickness is set to be semi-infinite in calculation (a sufficiently thick layered planar structure, equivalent to a semi-infinite plane in the thermal emission analysis. for example, when the thickness is more than 100mm, thermal emission performance analysis can be equivalently performed semi-infinite).

In fig. 15, (a) (b) (c) show the structure types of the radiant heat flux controlling device, respectively, (a) indicates the structure type as "intrinsic silicon bulk-potassium bromide bulk" in table 1, (b) indicates the structure type as "intrinsic silicon thin film-potassium bromide bulk" in table 1, and (c) indicates the structure type as "intrinsic silicon thin film-potassium bromide thin film" in table 1; in the diagrams below (a), (b) and (c), the radiation heat exchange coefficient diagrams of the thermal diode of the structure under forward and reverse temperature bias conditions are shown, respectively. Each point in the graph corresponds to an energy transmission channel under a specific frequency and a transverse wave vector, and the brighter the energy transmission channel, the stronger the energy transmission capability of the channel.

As can be seen from fig. 15, when the intrinsic silicon and the potassium bromide are both in a semi-infinite bulk structure, the thermal diode has many low- κ modes in both the forward and reverse directions, so there is almost no difference in the forward and reverse heat flows, and the rectification ratio is only 0.03; when the intrinsic silicon block material is replaced by a suspended 10nm film, the rectification ratio is increased to 1.67 multiplied by 10³This is mainly due to the low- κ mode being significantly attenuated; when the semi-infinite potassium bromide block material is also changed into a suspended 10nm film structure, the rectification ratio can be further improved to 2.52 multiplied by 10³The coupling of surface phonon polaritons on two sides of the potassium bromide film is mainly benefited, so that the peak of the local electromagnetic state density of the potassium bromide film is red shifted (namely, shifted to low frequency), and at the moment, the intrinsic silicon semiconductor in the corresponding frequency band can form larger difference of the local electromagnetic state density along with the temperature change, so that the rectification ratio is further improved.

This example also analyzed the change in rectification ratio of intrinsic silicon and potassium bromide combined thermal diode with film thickness under the suspended film structure. The analysis results are shown in FIG. 16. As can be seen from fig. 16, the thermal diode combining the intrinsic silicon thin film and the potassium bromide thin film provided by the present invention still has good thermal rectification performance within a large film thickness range: when the thickness of the intrinsic silicon film is 1-1000nm and the thickness of the potassium bromide film is 1-1000nm, the rectification ratio of the radiation heat flow regulating device is 1.67 multiplied by 10³-3.07×10³。

Example 4

The embodiment provides a radiation heat flow regulation device without a substrate, which comprises a first radiator and a second radiator, wherein the first radiatorThe body is made of intrinsic silicon material and the second radiator is made of doped silicon (doping concentration 10)¹⁸cm^-3) Material composition; the first radiator is arranged in a suspension manner; the distance between the first radiator and the second radiator is 100 nm. The embodiment analyzes the thermal rectification performance of the radiation heat flow regulation device when the first radiator and the second radiator have different thicknesses.

The embodiment analyzes the thermal rectification performance of the radiation heat flow regulation device with the following three typical structures, and the related parameters comprise: the temperature of the high temperature end was 1000K, the temperature of the low temperature stage was 300K, and the analysis results are shown in Table 2 and FIG. 17.

TABLE 2 Performance of thermal diodes based on different structures of intrinsic and doped silicon

In Table 2, the thickness of the thin film is 10nm, and the bulk indicates that the thickness is set to be semi-infinite in calculation (a sufficiently thick layered planar structure, equivalent to a semi-infinite plane in the thermal emission analysis. for example, when the thickness is more than 100mm, thermal emission performance analysis can be equivalently performed semi-infinite).

In fig. 17, (a) (b) (c) show the structure types of the radiation heat flow control device, respectively, (a) indicates the structure types as "intrinsic silicon bulk-doped silicon bulk" in table 2, (b) indicates the structure types as "intrinsic silicon thin film-doped silicon bulk" in table 2, and (c) indicates the structure types as "intrinsic silicon thin film-doped silicon thin film" in table 2; in the diagrams below (a), (b) and (c), the radiation heat exchange coefficient diagrams of the thermal diode of the structure under forward and reverse temperature bias conditions are shown, respectively. Each point in the graph corresponds to an energy transmission channel under a specific frequency and a transverse wave vector, and the brighter the energy transmission channel, the stronger the energy transmission capability of the channel.

As can be seen from fig. 17, when the intrinsic silicon and the doped silicon are both in the semi-infinite bulk structure, the thermal diode has many low- κ modes in both the forward and reverse directions, so there is almost no difference in the forward and reverse heat flows, and the rectification ratio is only that0.005; when the intrinsic silicon block material is replaced by a suspended 10nm film, the rectification ratio is increased to 4.66 multiplied by 10³This is mainly due to the low- κ mode being significantly attenuated; when the semi-infinite doped silicon block material is also changed into a suspended 10nm film structure, the rectification ratio can be further improved to 1.27 multiplied by 10⁴The coupling of the surface plasma polaritons on the two sides of the doped silicon film is mainly benefited, so that the peak of the local electromagnetic state density of the doped silicon film is red shifted (namely, shifted to low frequency), and at the moment, the intrinsic silicon semiconductor in the corresponding frequency band can form larger difference of the local electromagnetic state density along with the temperature change, so that the rectification ratio is further improved.

This example also analyzed the change in rectification ratio of intrinsic silicon and doped silicon combined thermal diodes under the suspended film structure with the film thickness. The analysis results are shown in FIG. 18. As can be seen from fig. 18, the thermal diode combining the intrinsic silicon thin film and the doped silicon thin film provided by the present invention can still have good thermal rectification performance within a large range of the thickness of the thin film: when the thickness of the intrinsic silicon film is 1-1000nm and the thickness of the doped silicon film is 1-1000nm, the rectification ratio of the radiation heat flow regulation device is 2 multiplied by 10³-4.67×10³。

Example 5

The embodiment provides a radiation heat flow regulating device comprising a substrate, which comprises a first radiator and a second radiator, wherein the first radiator is composed of an intrinsic silicon film and a first substrate, and the second radiator is composed of a potassium bromide film and a second substrate; the first substrate and the second substrate are both made of silver; the distance between the first radiator and the second radiator is 10 nm; the structural schematic diagram of the radiant heat flow regulating device is shown in fig. 19. The embodiment analyzes the thermal rectification performance of the radiation heat flow regulating and controlling device when the intrinsic silicon thin film and the potassium bromide thin film have different thicknesses, and related parameters comprise: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis result is shown in FIG. 20.

As can be seen from fig. 20, for the thermal diode with silver substrate, the thicknesses of intrinsic silicon and potassium bromide cannot be too thin, otherwise, the rectification ratio is very small because the silver substrate participates in the radiative heat exchange too much; when the thickness of the intrinsic silicon film is 10nm-1mm and the thickness of the potassium bromide film is 1 mu m-1mm, the rectification ratio of the radiation heat flow regulating device can reach more than 200.

Example 6

The present embodiment provides a radiation heat flow control device including a substrate, which includes a first radiator and a second radiator, wherein the first radiator is composed of an intrinsic silicon thin film and a first substrate, and the second radiator is made of doped silicon (doping concentration 10)¹⁸cm^-3) A film and a second substrate; the first substrate and the second substrate are both made of silver; the distance between the first radiator and the second radiator is 10 nm; the schematic structural diagram of the radiant heat flow regulating device is shown in fig. 21. The embodiment analyzes the thermal rectification performance of the radiation heat flow regulation device when the intrinsic silicon thin film and the doped silicon thin film have different thicknesses, and related parameters comprise: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis result is shown in FIG. 22.

As can be seen from fig. 22, for the thermal diode with the silver-containing substrate, the thicknesses of the intrinsic silicon and the doped silicon cannot be too thin, otherwise, the rectification ratio is very small because the silver substrate participates in the radiation heat exchange too much; when the thickness of the intrinsic silicon film is 10-100 μm and the thickness of the doped silicon film is 100-1 mm, the rectification ratio of the radiation heat flow regulation device can reach about 80. The thermal diode of this embodiment can achieve a lower rectification ratio than the thermal diode of embodiment 3, mainly due to the larger κ -mode resulting from the separation of the metal substrate by the doped semiconductor material compared to the polar material.

Example 7

The present embodiment provides a radiation heat flux regulating device including a non-metal substrate, which includes a first radiator and a second radiator, wherein the first radiator is composed of an intrinsic silicon thin film and a first substrate, and the second radiator is doped with silicon (doping concentration 6 × 10)¹⁸cm^-3) The film, the potassium bromide film and the second substrate; the first substrate and the second substrate are both made of silver; the distance between the first radiator and the second radiator is 10 nm; the structural schematic diagram of the radiation heat flow regulating device is shown in FIG. 23As shown. In this embodiment, it is analyzed that when the thickness of the doped silicon thin film is 1nm, and the intrinsic silicon thin film and the doped silicon thin film have different thicknesses, the thermal rectification performance of the radiation heat flow control device includes the following relevant parameters: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis result is shown in FIG. 24.

In contrast to the thermal diode provided in example 4, the thermal diode of this example incorporates a layer of polar material as a spacer between the layer of doped semiconductor material and the second substrate. Since the real part of the dielectric constant, ε', of potassium bromide is smaller than that of doped silicon, spacing the silver substrate with potassium bromide does not introduce much low- κ mode. As can be seen from FIG. 24, when the thickness of the intrinsic silicon thin film is 10nm-1mm and the thickness of the potassium bromide thin film is 1 μm-1mm, the rectification ratio of the radiation heat flow control device can reach more than 400; when the thickness of the intrinsic silicon film is 20nm-1mm and the thickness of the potassium bromide film is 1 mu m-1mm, the rectification ratio of the radiation heat flow regulating device can reach about 700.

Example 8

The embodiment provides a radiation heat flow regulating device comprising a substrate, which comprises a first radiator and a second radiator, wherein the first radiator is composed of an intrinsic silicon thin film (the thickness is 10nm) and a first substrate, and the second radiator is composed of cubic boron nitride; the first substrate is made of potassium bromide, the thickness of the intrinsic silicon thin film is 10nm, and the first radiator is arranged in a suspended mode; the second radiator is a block material; the distance between the first radiator and the second radiator is 100 nm; the schematic structural diagram of the radiant heat flow regulating device is shown in fig. 25.

This embodiment analyzes the thermal rectification performance of the radiant heat flow regulating device when the first substrate has different thicknesses, and the related parameters include: the temperature of the high temperature end is 1000K, the temperature of the low temperature section is 300K, and the analysis results are shown in Table 3. For comparison, the results of the performance analysis of the first substrate being absent, i.e., the first substrate having a thickness of 0, are also listed in table 3.

TABLE 3 thermal diode Performance for potassium bromide substrates of varying thickness

According to the results shown in table 3, when the first radiator is in a suspended configuration, the semiconductor material layer can be covered on the non-metal substrate, and such a configuration can also obtain a larger thermal rectification performance. However, as the thickness of the non-metal substrate layer increases, its contribution to near-field thermal radiation increases, and the radiant heat flow contributed by the non-metal substrate is insensitive to changes in the temperature bias direction of the thermal diode, thus resulting in a gradual degradation of the rectification performance.

In addition, it was found through analysis that a similar situation also occurs when the second radiator employs the second substrate composed of a non-metal. When the second radiator is arranged in a suspended manner, the polar material layer or the doped semiconductor material layer in the second radiator covers the second substrate made of the non-metallic material, and the better thermal rectification performance can be obtained.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. The radiation heat flow regulating and controlling device is characterized by comprising a first radiator and a second radiator, wherein the first radiator and the second radiator are arranged oppositely;

2. The radiant heat flow regulating device according to claim 1, characterized in that the first radiator and the second radiator are spaced apart by a distance of 1nm to 10mm, preferably 10nm to 100 μm.

3. The radiant heat flux modulating device of claim 1 wherein the layer of semiconductor material has a thickness of 1nm to 100 mm; more preferably 1nm to 1 mm;

preferably, in the semiconductor material layer, the volume proportion of the semiconductor material is 30% -100%;

preferably, the semiconductor is selected from one or a combination of two or more of silicon, germanium, gallium phosphide, gallium arsenide, indium arsenide, boron, tellurium, selenium, gallium nitride, indium nitride, aluminum oxide, silicon carbide, zinc oxide, silicon nitride, gallium antimonide, zinc sulfide, cadmium telluride, mercury telluride, cuprous bromide, cuprous iodide, bismuth telluride, bismuth selenide, bismuth sulfide, and arsenic telluride.

4. The radiant heat flux modulating device of claim 1 wherein the first metallic material layer comprises more than 20% by volume of metallic material; preferably, the metal material is selected from one or a combination of two or more of silver, gold and aluminum;

preferably, the distance from the midpoint of a vertical line between the first radiator and the second radiator to the first metal material layer is 10nm-100 mm;

preferably, the thickness of the first substrate is 1nm-100 mm;

preferably, the thickness of the first metal material layer is 1nm-100 mm.

5. The radiant heat flux modulating device of claim 1 wherein said second radiator is provided with one or a combination of a layer of polar material, a layer of doped semiconductor material.

6. The radiant heat flux modulating device of claim 5 wherein the polar material layer comprises 30% to 100% polar material by volume;

preferably, the polar material is selected from one or a combination of more than two of sodium chloride, potassium bromide, potassium chloride, barium fluoride, cesium fluoride, calcium fluoride, lithium fluoride, gallium nitride, magnesium oxide, cesium bromide, cesium iodide, zinc sulfide, silver bromide, silver chloride, cubic boron nitride, silicon carbide, silicon dioxide, hexagonal boron nitride, zinc selenide, sapphire, cadmium telluride and silicon dioxide;

preferably, the thickness of the polar material layer is 1nm-100 mm; more preferably 1nm to 10 mm.

7. The radiant heat flux modulating device of claim 5 wherein said doped semiconductor layer is doped with a carrier doping concentration greater than 10¹⁵cm^-3Doped semiconductor material of (a);

preferably, the semiconductor is selected from one or a combination of more than two of silicon, germanium, gallium phosphide, gallium arsenide, indium arsenide, boron, tellurium, selenium, gallium nitride, indium nitride, aluminum oxide, silicon carbide, zinc oxide, silicon nitride, gallium antimonide, zinc sulfide, cadmium telluride, mercury telluride, cuprous bromide, cuprous iodide, bismuth telluride, bismuth selenide, bismuth sulfide, and arsenic telluride;

preferably, the thickness of the doped semiconductor layer is 1nm-100 mm; more preferably 1nm to 10 mm.

8. The radiant heat flux modulating device of claim 5 wherein said second radiator further comprises a second substrate, said second substrate being covered by one or a combination of a layer of polar material, a layer of doped semiconductor material;

the second substrate comprises a second metal material layer, and the metal material proportion in the second metal material layer is more than 20% (V/V); preferably, the metal material is selected from one or a combination of two or more of silver, gold and aluminum;

preferably, the distance between the midpoint of a vertical line between the first radiator and the second metal material layer is 10nm-100 mm;

preferably, the thickness of the second metal material layer is 1nm-100 mm.

9. The radiant heat flux regulating device of claim 1, wherein one or more radiators are further disposed between said first radiator and said second radiator.

10. Use of a radiant heat flow regulating device according to any one of claims 1 to 9 for heat flow regulation.

11. A thermal flow regulator comprising the radiant heat flow modulating device of any one of claims 1-9;

preferably, the thermal current regulator is a thermal diode, a thermal triode, or a thermal switch.