JP7084172B2 - Manufacturing method of heat radiation structure - Google Patents

Description

The present invention relates to a method for manufacturing a heat radiating structure capable of radiating heat.

It is desired that the temperature of electronic devices including electronic components is kept within an appropriate range from the viewpoint of the performance and life of the electronic components. Therefore, if thermal management can contribute to the efficiency improvement of various industrial equipment, it can have a very large impact such as environmental measures such as reduction of CO ₂ emissions. Of the three modes of heat transfer (conduction, convection, and radiation), heat radiation has high controllability. Therefore, in order to control the temperature of an electronic device, a heat control device that can be controlled by using heat radiation (heat radiation) in the device has been developed. As such a thermal control device, one having a metal / dielectric / metal (MIM) structure is known, which is a dielectric between two metals (conductor layers). It is known that the resonance caused by the formation of the LC resonance circuit in the layer is used, and the radiant heat flow can be controlled by forming various metal patterns on the dielectric.

In the formation of a metal pattern in the conventional production of a MIM structure, mask pattern transfer by electron beam drawing and surface processing by RIE (Reactive Ion Etching) are required, and such a method is expensive and laborious. There was a problem that it took. For example, Patent Document 1 describes that a MIM element pattern of a screen portion is formed by a sequential exposure method in a method of manufacturing a MIM element used for a MIM liquid crystal panel.

On the other hand, conventionally, it has been known to control the heat of an object whose heat should be controlled by using a phase transition material, that is, by utilizing the difference in properties between the high temperature phase and the low temperature phase of the phase transition material. (For example, Patent Document 2-4). The phase transition material has a unique phase transition temperature or a unique thermal radiation characteristic depending on the respective material composition.

Here, Patent Document 5 discloses a method of forming a layer of a phase transition material such as VO ₂ on a substrate, but Patent Document 5 transmits visible light while suppressing transmission of infrared light. It relates to a method for manufacturing coated glass. In Patent Document ₅ , plasmon resonance between VO2 particles is used to suppress the transmission of infrared light. According to Patent Document 5, it is preferable that the VO2 nanoparticles _are dispersed at a specific average particle size or less in order to realize a decrease in transmittance in the near infrared region due to plasmon absorption.

Japanese Unexamined Patent Publication No. 6-22394 Japanese Unexamined Patent Publication No. 11-217562 Japanese Unexamined Patent Publication No. 2002-120799 Japanese Unexamined Patent Publication No. 1-212699 JP-A-2015-137184

K. Ito, K. Nishikawa, H. Iizuka, H. Toshiyoshi, “Experimental investigation of radiative thermal rectifier using vanadium dioxide,” Applied Physics Letters 105, No. 25, 253503 (2014).

Here, if it is possible to form a layer of the phase transition material on the derivative layer in some form to form a thermal radiation structure that causes resonance at a predetermined temperature, such a thermal radiation structure The body can change the heat release properties of the phase transition material used, which is very beneficial as it expands the variety of materials that can be selected as the phase transition material. However, in the production of such a thermal radiation structure, when a layer of the phase transition material is formed, resist is applied for pattern formation, and etching is performed with argon gas or the like, residual phase transition material occurs or the phase transition occurs. There is also the problem that the shape of the material becomes unstable.

Therefore, it is an object of the present invention to provide a simple and economical method for manufacturing a heat radiating structure capable of radiating heat.

In the production of the thermal radiation structure, the present inventors perform heat treatment after forming a phase transition material layer on the dielectric layer so that resonance occurs on the dielectric layer at a desired temperature. It has been found that a film in which particles of a phase transition material are dispersed can be formed, whereby a thermal radiation structure having desired radiation characteristics can be obtained.

That is, the present invention includes the following inventions.
[1] The following steps:
(A) A step of preparing a substrate, a substrate including a conductor layer on the substrate, and a dielectric layer on the conductor layer;
(B) A step of forming a phase transition material layer on the dielectric layer; and (c) heat-treating the base material on which the phase transition material layer is formed to form particles of the phase transition material on the dielectric layer. A method for producing a heat radiating structure capable of radiating heat, which comprises a step of forming a dispersed film.
[2] The method for producing a heat-radiating structure according to [1], wherein the average particle size of the particles of the phase transition material is 5 nm or more and 3000 nm or less.
[3] The method for producing a heat-radiating structure according to [2], wherein the average particle size of the particles of the phase transition material is 500 nm or more and 3000 nm or less.
[4] The method for producing a heat radiating structure according to any one of [1] to [3], which forms a phase transition material layer of 5 nm or more and 3000 nm or less in the step (b).
[5] The method for producing a heat radiating structure according to any one of [1] to [4], wherein the heat treatment is performed at an oxygen pressure of 2 to 30 Pa in the step (c).
[6] The phase transition material is VO ₂ , M _x V _1-x O ₂ (M is W, Ti, Re, Ir, Os, Ru, Nb, Ta, Mo or Mg, and 0 <X <1. ), The method for producing a heat radiating structure according to any one of [1] to [5], which is at least one selected from the group consisting of Ti ₂ O ₃ and WO ₃ .
[7] The dielectric layer is amorphous silicon, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), polysilicon, polygermanium, zinc sulfide (ZnS), zinc selenide (ZnSe), diamond, and potassium bromide. The method for producing a heat-radiating structure capable of radiating heat according to any one of [1] to [6], which is at least one selected from the group consisting of (KBr).

According to the present invention, a heat radiating structure capable of radiating heat can be easily and economically manufactured.

It is a figure which shows the SEM image of the heat radiation structure of Example 1. FIG. It is a figure which shows the SEM image of the heat radiation structure of Example 2. It is a schematic sectional drawing for demonstrating the structure of the heat radiation structure 10 of this embodiment. It is a schematic perspective view of the heat radiation structure of FIG. It is a schematic perspective view for demonstrating the dimensional example of the heat radiation structure (1 cell) of FIG. It is a graph which shows the simulation result performed in Example 3 about the radiation characteristic at a high temperature of a thermal radiation structure 10. It is a graph which shows the simulation result performed in Example 3 about the radiation characteristic at a low temperature of a thermal radiation structure 10.

The present invention relates to a method for manufacturing a heat radiating structure capable of radiating heat, and prepares the following steps: (a) a substrate, a substrate including a conductor layer on the substrate, and a dielectric layer on the conductor layer. And (b) a step of forming a phase transition material layer on the dielectric layer; (c) a base material on which the phase transition material layer is formed is heat-treated, and the phase transition material is formed on the dielectric layer. It includes a step of forming a film in which the particles of the above are dispersed (hereinafter, also referred to as a production method of the present invention). According to the manufacturing method of the present invention, it is economical because it is not necessary to draw an electron beam or perform RIE as in the conventional case, and it is desired to have a stable shape without leaving a phase transition material on the dielectric layer. It is possible to easily form a film in which particles of the phase transition material are dispersed so that resonance occurs at temperature. The thermal radiation structure obtained by the production method of the present invention can control the radiant heat flow with high contrast between the high temperature phase and the low temperature phase of the phase transition material used.

The manufacturing method of the present invention includes a step (a) of preparing a substrate including a substrate, a conductor layer on the substrate, and a dielectric layer on the conductor layer. The step of preparing such a base material is not particularly limited, but after forming a conductor layer on the surface of the substrate by, for example, sputtering, the surface of the conductor layer is made dielectric by, for example, the ALD method (atomic layer deposition). Examples include a method of forming a body layer. Here, an adhesive layer may be provided between the substrate and the conductor layer.

Specific examples of the material of the substrate include Al ₂ O ₃ , TIO ₂ , quartz, glass, Si and the like. The substrate may be, for example, a part of an object whose temperature is controlled. Further, the substrate may be a part of a heater for radiating and heating heat, for example. Further, the heat radiation structure obtained by the manufacturing method of the present invention including the substrate may be used as a heat control device or a heat radiation device.

Examples of the material of the conductor layer on the substrate include metal, and specific examples thereof include gold, aluminum (Al), tungsten, and tantalum. A person skilled in the art considers the material of the dielectric layer and the phase transition material constituting the phase transition material layer to be formed in the step (b) described later, and imparts desired radiation characteristics to the obtained thermal radiation structure. From the viewpoint, the material of the conductor layer can be appropriately selected. The thickness of the conductor layer is not particularly limited, but is preferably 100 nm to 500 nm from the viewpoint of ensuring an optically sufficient thickness for achieving high thermal radiation contrast.

Examples of the material of the dielectric layer on the conductor layer include amorphous silicon, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), polysilicon, polygermanium, zinc sulfide (ZnS), and zinc selenide (ZnSe). ), Diamond, potassium bromide (KBr) and the like. A person skilled in the art considers the material of the conductor layer and the phase transition material constituting the phase transition material layer to be formed in the step (b) described later, and imparts desired radiation characteristics to the obtained thermal radiation structure. The material of the dielectric layer can be selected from. The thickness of the dielectric layer is not particularly limited, but is preferably 30 nm to 300 nm in order to achieve complete resonance in the metal phase.

The production method of the present invention includes a step (b) of forming a phase transition material layer on the dielectric layer. As the phase transition material constituting the phase transition material layer formed in the step (b), for example, the conductivity in the high temperature phase is larger than the conductivity in the low temperature phase, and the thermal radiation coefficient in the high temperature phase. Is a material that is smaller than the heat radiation rate in the low temperature phase (more specifically, it has metallic properties in the high temperature phase, insulator properties in the low temperature phase, and the heat radiation rate in the high temperature phase. A material that is small and has a large heat emission rate in the low temperature phase) can be used. The phase transition material is VO ₂ , M _x V _1-x O ₂ (M is W, Ti, Re, Ir, Os, Ru, Nb, Ta, Mo or Mg, and 0 <X <1). , Ti ₂ O ₃ , and WO ₃ , etc., and VO ₂ is preferable because it exhibits a phase transition temperature near room temperature. Vanadium dioxide generally has a phase transition temperature near 70 ° C. (343K). Further, M (W, Ti, Re, Ir, Os, Ru, Nb, Ta, Mo or Mg) in the above M _x V _1-x O ₂ is used as a doping element for lowering the transition temperature of VO ₂ . Such materials include "Table I" on page 495 of J. Solid State Chem., 3, 490-500 (1971) and "App. Phys. Lett., 95, 171909 (2009)". Can be referred to. Further, in the phase transition material, it is preferable that the resistance value in the high temperature phase and the resistance value in the low temperature phase differ by three orders of magnitude or more.

In the step (b), the method for forming the phase transition material layer is not particularly limited, and examples thereof include physical vapor deposition methods such as sputtering, pulse laser ablation (PLD), and electron beam (EVD). Since it is possible to form a film on a large area, it is preferable to perform it by sputtering. A phase transition material layer is formed by using the above method using V and / or M (M is W, Ti, Re, Ir, Os, Ru, Nb, Ta, Mo or Mg). be able to.

When the phase transition material layer is formed by sputtering, the conditions are not particularly limited as long as a phase transition material layer made of a desired phase transition material can be obtained, and can be appropriately adjusted by a person skilled in the art, for example. The input power to the target is preferably 10 to 100 W, the substrate temperature is preferably 250 to 350 ° C., and it is preferably carried out in an oxygen-containing inert gas. Examples of the inert gas include He gas, Ne gas, Ar gas, Xe gas, N ₂ gas and the like, of which Ar gas is preferable.

The thickness of the phase transition material layer to be formed in the step (b) is preferably 5 nm or more and 3000 nm or less from the viewpoint of forming particles of the phase transition material having a desired average particle size in the subsequent step (c). It is more preferably 50 nm or more and 3000 nm or less, further preferably 500 nm or more and 3000 nm or less, and particularly preferably 510 nm or more and 3000 nm or less. The larger the thickness of the phase transition material layer, the larger the average particle size of the particles of the phase transition material obtained in the subsequent step (c). The thickness of the phase transition material layer can be adjusted, for example, by adjusting the film formation time.

The production method of the present invention includes a step (c) of heat-treating a base material on which a phase transition material layer is formed to form a film in which particles of the phase transition material are dispersed on a dielectric layer. By adjusting the oxygen pressure at which the heat treatment is performed, the average particle size of the particles of the obtained phase transition material can be adjusted, and from this viewpoint, it is preferable to perform the heat treatment at an oxygen pressure of 2 to 30 Pa. Specifically, by increasing the oxygen pressure, the average particle size of the particles of the phase transition material can be increased. Other heat treatment conditions are not particularly limited as long as particles of the phase transition material having a desired average particle size can be formed, and can be appropriately adjusted by those skilled in the art, for example, the temperature is 550 to 650. The temperature is preferably set to 30 minutes to 2 hours.

The average particle size of the particles of the phase transition material obtained in the step (c) is preferable from the viewpoint of causing resonance at a desired temperature and controlling the radiant heat flow with high contrast between the high temperature phase and the low temperature phase of the phase transition material. Is 5 nm or more and 3000 nm or less, more preferably 50 nm or more and 3000 nm or less, further preferably 500 nm or more and 3000 nm or less, and particularly preferably 510 nm or more and 3000 nm or less. The average particle size is obtained by calculating the area of each particle included in the photograph of the SEM image, then calculating the average area per particle, and calculating the diameter of the circle having the average area. The proportion of the total particles of the phase transition material on the dielectric layer is not particularly limited, but may be preferably 15 to 90%, more preferably 30 to 90%.

In one embodiment of the production method of the present invention, a phase transition material layer having a thickness of 5 nm or more and 3000 nm or less is formed in the step (b), and heat treatment is performed at an oxygen pressure of 2 to 30 Pa in the step (c). As a result, particles of the phase transition material having an average particle size of 5 nm or more and 3000 nm or less can be formed on the dielectric layer.

In another embodiment of the production method of the present invention, a phase transition material layer having a thickness of 1 nm or more and 100 nm or less is formed in the step (b), and heat treatment is performed at an oxygen pressure of 8 to 20 Pa in the step (c). As a result, particles of the phase transition material having an average particle size of 5 nm or more and 3000 nm or less can be formed on the dielectric layer.

In still another embodiment of the production method of the present invention, a phase transition material layer having a thickness of 10 nm or more and 1000 nm or less is formed in the step (b), and heat treatment is performed at an oxygen pressure of 2 to 8 Pa in the step (c). As a result, particles of the phase transition material having an average particle size of 50 nm or more and 3000 nm or less can be formed on the dielectric layer.

In the film in which the particles of the phase transition material obtained in the step (c) are dispersed, the primary particles of the particles may be dispersed, or the primary particles of the particles aggregate to form secondary particles, and the secondary particles thereof. May be dispersed, or such primary particles and secondary particles may be mixed and dispersed. Such a form in which the particles of the phase transition material are dispersed can be obtained by self-assembling the phase transition material by heat treatment of the phase transition material layer. Here, "dispersed" means that the particles are separated from each other by 5 nm or more, preferably 10 nm or more, and more preferably 50 nm or more.

Here, a mechanism having the opposite characteristics to the heat release characteristics of the phase transition material used in the thermal radiation structure obtained by the production method of the present invention will be described.

First, a case where the temperature of the heat radiation structure is high, that is, a case where the temperature of the heat radiation structure is equal to or higher than the phase transition temperature of vanadium dioxide (for example, 345 K or higher) will be described. When the temperature of the thermal radiation structure is high, the phase transition material composed of vanadium dioxide has conductivity, and the thermal radiation structure has a structure in which a dielectric layer is sandwiched between two conductor layers. Thereby, the heat radiating structure functions as a metamaterial emitter having a property of being able to radiate heat mainly as infrared rays. This property is believed to be due to the resonance phenomenon described by Magnetic polariton. The magnetic polariton is a resonance phenomenon in which a strong electromagnetic field confinement effect is obtained in a dielectric (dielectric layer) between two upper and lower conductors (particles of a phase transition material and a conductor layer). As a result, in a high-temperature thermal radiation structure, the portion of the dielectric layer sandwiched between the particles of the phase transition material and the individual conductor layer of the conductor layer, and the portion of the conductor layer in contact with the dielectric layer are the radiation sources of infrared rays. It becomes. Then, the infrared rays emitted from the radioactive source are radiated to the surrounding environment. Further, in this thermal radiation structure, the resonance wavelength can be adjusted by adjusting the shape or dispersion structure of the particles of the phase transition material, the material of the dielectric layer or the conductor layer, or the particles of the phase transition material. Conceivable. As a result, the emissivity of the radiation surface of the thermal radiation structure exhibits a characteristic of increasing at a specific wavelength.

Next, a case where the temperature of the heat radiation structure is low, that is, a case where the temperature of the heat radiation structure is lower than the phase transition temperature of vanadium dioxide (for example, 335 K or less) will be described. When the temperature of the thermal radiation structure is low, the phase transition material composed of vanadium dioxide becomes an insulating property, and the conductivity of the low temperature phase is significantly smaller than that of the high temperature phase. Therefore, the thermal radiation structure does not function as the metamaterial emitter as described above, and the resonance phenomenon does not occur. As a result, the heat radiation coefficient of the heat radiation structure at low temperature is smaller than the heat radiation rate of the heat radiation structure at high temperature. The heat radiation coefficient of the heat radiation structure at low temperature reflects the heat radiation from the substrate side due to the presence of the conductor layer (metal layer), and can suppress the permeation of the phase transition material to the particle side. , Low compared to the thermal radiation of vanadium dioxide in the low temperature phase.

For the above reasons, the thermal radiation structure obtained by the production method of the present invention has properties opposite to those of the phase transition material used.

The thermal radiation structure obtained by the production method of the present invention has a thermal emissivity contrast calculated based on the radiation intensity between the high temperature phase (for example, 345K or more) and the low temperature phase (for example, 335K or less) of the phase transition material used. However, it can be 2 to 10 times.

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be carried out in various embodiments as long as it belongs to the technical scope of the present invention.

Hereinafter, the present invention will be described based on examples. The present invention is not limited to the following examples.

[Example 1: Production of thermal radiation structure 1]
(1) The base material used was as follows:
Substrate: Si substrate, 5250 nm
Conductor layer: Tungsten, 100 nm
Dielectric layer: amorphous silicon, 300 nm.
(2) Formation of a phase transition material layer A 10 nm phase transition material layer made of VO ₂ was formed on the above-mentioned substrate by sputter film formation. The conditions for sputter film formation are as follows:
Spatter gas: Ar (99.5%) + O ₂ (0.5%)
Target: Vanadium Spatter input power: 100W
Base material temperature: 350 ° C.
(3) Formation of dispersion film of particles of phase transition material The substrate on which the phase transition material layer is formed is heat-treated at 600 ° C. for 1 hour in an atmosphere of oxygen pressure of 8 Pa to form a dispersion film of particles of VO ₂ . And obtained a heat radiation structure.

[Example 2: Production of thermal radiation structure 2]
A thermal radiation structure was obtained in the same manner as in Example 1 except that a 100 nm phase transition material layer was formed by adjusting the film formation time in the above “(2) Formation of phase transition material layer”.

SEM images of the thermal radiation structures of Examples 1 and 2 are shown in FIGS. 1A and 1B, respectively. The average particle size of the VO2 crystal grains in the thermal radiation structure of Example ₁ obtained from the SEM image of FIG. 1A was about 120 nm, and the ratio of the total particles contained in the photograph of the SEM image was 26%. The average particle size of the VO2 crystal grains in the thermal radiation structure of Example ₂ obtained from the SEM image of FIG. 1B was about 1000 nm, and the ratio of the total particles contained in the photograph of the SEM image was 35%. In both the heat radiating structure of Example 1 and the heat radiating structure of Example ₂ , the VO2 crystal grains exist as substantially independent primary particles, and some of them are secondary by connecting several primary particles. The particles were formed, but both the primary particles and the secondary particles were dispersed. The average particle size was determined as follows. That is, after calculating the area of each particle included in the photograph of the SEM image, the average area per particle was calculated, the diameter of the circle having the average area was calculated, and the value was taken as the average particle size.

[Example 3: Verification using simulation]
In order to verify the thermal radiation characteristics of the thermal radiation structure obtained by the manufacturing method of the present invention, analysis was performed using an electromagnetic field simulator (software name: CST MICROWAVE STUDIO 2016).

The structure of the analyzed thermal radiation structure is shown in Figure 2-4. FIG. 2 is a schematic cross-sectional view for explaining the configuration of the heat radiation structure. FIG. 3 is a schematic perspective view of the heat radiation structure of FIG. FIG. 4 is a schematic perspective view for explaining a dimensional example of the heat radiation structure (1 cell) of FIG. FIG. 2 corresponds to a cross-sectional view when the thermal radiation structure of FIG. 3 is cut along the dotted line AA'in the direction of the arrow. The left-right direction, front-back direction, and up-down direction are as shown in FIG. 3 or 4. In the thermal radiation structure 10, particles of the phase transition material formed on the substrate 4, the conductor layer 1 on the substrate 4, the dielectric layer 3 on the conductor layer 1, and the dielectric layer 3 are dispersed. Includes the formed film 2. Here, it is assumed that the shape of the film 2 in which the particles of the phase transition material formed on the dielectric layer 3 are dispersed is a hemisphere and is regularly dispersed as shown in FIG. Therefore, the average particle size of the particles of the phase transition material corresponds to "W" in FIGS. 2 and 4.

Regarding the composition of the analyzed thermal radiation structure 10, vanadium dioxide (VO ₂ ) was used as the phase transition material, tungsten (W) was used as the conductor layer 1, and amorphous silicon was used as the dielectric layer 3. In the electromagnetic field simulation, the substrate 4 is omitted. This is because tungsten is used as the conductor layer 1, and since the tungsten is optically thick enough, the upper and lower parts of the conductor layer 1 are separated by an electromagnetic field, which affects the result without setting the substrate 4. Because there is no.

The dimensions of the composition of the analyzed thermal radiation structure 10 are as follows:
P _w : 1300 nm
W: 1050 nm
t ₁ : 100 nm
t ₂ : 525 nm
t ₃ : 300 nm
The vertical width _L (width in the front-rear direction) and the pitch PL in the vertical direction (pitch in the front-rear direction) are the same as the width W (width in the left-right direction) and the pitch P _W in the horizontal direction (pitch in the left-right direction), respectively. Set to dimensions.

As the dielectric constant of each material constituting the analyzed thermal radiation structure 10, the following definition formula was referred to:
(Vanadium dioxide)
Definition formula: Refer to Non-Patent Document 1 Parameter: Refer to Non-Patent Document 1 (Amorphous silicon)
Definition formula: ε ＝ ε'＋ iε''
Parameters: ε'= 13, ε'' = 1
(tungsten)
See "W (Tungsten)" and "Ordal et al. 1988: n, k 0.667-200 μm" in "Refractive Index.INFO-Refractive index database" (https://refractiveindex.info/).

Figures 5 and 6 show the simulation results. FIG. 5 shows the result of analyzing the radiation characteristics of the thermal radiation structure 10 using the dielectric constant when the phase transition material (vanadium dioxide) is a high temperature phase (345K). FIG. 6 shows the results of analysis of the radiation characteristics of the thermal radiation structure 10 using the dielectric constant when the phase transition material (vanadium dioxide) is a low temperature phase (335K). For reference, FIGS. 5 and 6 also show the radiation spectra of the blackbody at each temperature. From FIGS. 5 and 6, it can be seen that the heat radiation rate of the heat radiation structure 10 at low temperature is smaller than the heat radiation rate of the heat radiation structure 10 at high temperature.

The radiation characteristics of the heat radiation structure 10 have a high heat emissivity at a high temperature and a low heat emissivity at a low temperature. This characteristic is different from the radiation characteristic of vanadium dioxide, which is a phase transition material, (radiation characteristic having a low thermal radiation rate in the high temperature phase and a high thermal radiation rate in the low temperature phase). This result shows that the heat release property of the phase transition material used can be reversed by the configuration of the heat radiation structure 10.

Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to this embodiment, and even if there are design changes within the scope of the gist of the present invention, they are the present invention. It is included in the invention.

Claims (6)

The following steps:
(A) A step of preparing a substrate, a substrate including a conductor layer on the substrate, and a dielectric layer on the conductor layer;
(B) A step of forming a phase transition material layer on the dielectric layer; and (c) heat-treating the base material on which the phase transition material layer is formed to form particles of the phase transition material on the dielectric layer. Including the step of forming a dispersed film
The materials of the dielectric layer are amorphous silicon, alumina (Al ₂ O ₃ ), silica (SiO ₂ ), polysilicon, polygermanium, zinc sulfide (ZnS), zinc selenide (ZnSe), diamond, and potassium bromide (ZnSe). A method for producing a heat-radiating structure capable of radiating heat , which is at least one selected from the group consisting of KBr) . The method for producing a heat-radiating structure capable of radiating heat according to claim 1, wherein the average particle size of the particles of the phase transition material is 5 nm or more and 3000 nm or less. The method for producing a heat-radiating structure according to claim 2, wherein the average particle size of the particles of the phase transition material is 500 nm or more and 3000 nm or less. The method for producing a heat-radiating structure according to any one of claims 1 to 3, wherein a phase transition material layer having a thickness of 5 nm or more and 3000 nm or less is formed in the step (b). The method for producing a heat radiating structure capable of radiating heat according to any one of claims 1 to 4, wherein the heat treatment is performed at an oxygen pressure of 2 to 30 Pa in the step (c). The phase transition material is VO ₂ , M _x V _1-x O ₂ (M is W, Ti, Re, Ir, Os, Ru, Nb, Ta, Mo or Mg, 0 <X <1),. The method for producing a heat radiating structure capable of radiating heat according to any one of claims 1 to 5, which is at least one selected from the group consisting of Ti ₂ O ₃ and WO ₃ .

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