Heat radiation light source

Abstract

This invention provides a thermal radiation source that can be configured to expose a substrate and a thermal radiation layer to the atmosphere, and, in 4 m Narrow-band wavelengths below m have high emissivity and are greater than 4 m The emissivity of wavelengths with wavelengths of m is low. A thermal radiation light source comprises a thermal radiation layer (N) and a substrate (K) for heating the thermal radiation layer (N). The thermal radiation layer (N) is configured such that a radiation control section (Na) having a MIM stack (M) and a radiation-emitting transparent oxide layer (Nb) formed of transparent oxide are stacked in sequence on one side close to the substrate (K). The MIM stack (M) positions a resonance transparent oxide layer (R) formed of transparent oxide between platinum layers (P) arranged along the stacking direction. The thickness of the resonance transparent oxide layer (R) is 4... m The thickness of wavelengths below m is the resonant wavelength.

Description

Technical Field

[0001] The present invention relates to a thermal radiation light source having a thermal radiation layer and a substrate for heating the thermal radiation layer stacked thereon. Background Technology

[0002] The thermal radiation source is generated by heating the thermal radiation layer to a high temperature using a substrate, so that the radiation light from the heated object is emitted from the thermal radiation layer.

[0003] As the aforementioned thermal radiation source, there are thermal radiation sources in which a substrate and a thermal radiation layer are disposed in a sealed state inside a sealed tube formed of a light-transmitting and airtight component such as quartz glass, so that the inside of the sealed tube becomes a vacuum state, or inert gas such as nitrogen is sealed inside the sealed tube (see, for example, Patent Document 1).

[0004] In Patent Document 1, the substrate is made of a high-melting-point metal such as tungsten that heats up when an electric current flows through it, and the heat radiation layer is formed of a metal layer such as tantalum or molybdenum. The substrate or heat radiation layer is disposed inside a sealed tube in a sealed state to prevent the substrate or heat radiation layer from deteriorating due to oxidation.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent document 1: Japanese Patent Application Publication No. 2015-138638. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] Traditional thermal radiation light sources involve sealing the substrate or thermal radiation layer inside a sealed tube, resulting in a complex and expensive overall structure. Therefore, there is an urgent need for thermal radiation light sources that allow the substrate and thermal radiation layer to be exposed to the atmosphere.

[0010] Furthermore, for purposes such as heating the object through quartz glass like a heating lamp, there is an urgent need for 4 μ The wavelengths in the narrow band below m (i.e., the narrow band below the mid-infrared) have high emissivity (radioactivity) and are greater than 4. μ A thermal radiation source with a wavelength of m (i.e., far-infrared light) and low emissivity (radioactivity).

[0011] That is, for example, when heating an object through quartz glass, if the radiation is greater than 4... μ When far-infrared light with a wavelength of m is emitted, the quartz glass absorbs the far-infrared light and reaches a high temperature. Therefore, large-scale equipment is needed to cool the quartz glass, and the equipment used to heat the object stored inside the quartz glass tube becomes complicated, among other disadvantages.

[0012] The present invention is proposed in view of the above-mentioned facts, and its object is to provide a thermal radiation light source that can be configured to expose the substrate and the thermal radiation layer to the atmosphere, and moreover, in 4 μ Narrow-band wavelengths below m have high emissivity and are greater than 4 μ The emissivity of wavelengths with wavelengths of m is small.

[0013] Methods for solving problems

[0014] The thermal radiation light source of the present invention is a thermal radiation light source having a thermal radiation layer and a substrate for heating the thermal radiation layer stacked together, characterized in that:

[0015] The aforementioned thermal radiation layer is configured such that the radiation control section having a MIM stack and the radiation-emitting transparent oxide layer formed of transparent oxide are stacked in such a manner that the radiation control section having a MIM stack and the radiation-emitting transparent oxide layer are located on one side close to the substrate, wherein the MIM stack places the resonance-emitting transparent oxide layer formed of transparent oxide between a pair of platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate.

[0016] The thickness of the aforementioned transparent oxide layer for resonance is 4. μ The thickness of wavelengths below m is the resonant wavelength.

[0017] That is, since the thermal radiation layer is constructed in the following state: the radiation control section having a MIM stacked portion and the radiation transparent oxide layer having a radiation control section having a radiation control section having a radiation transparent oxide layer having a radiation control section having a radiation control section having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a radiation control section having a radiation control section having a radiation control section having a MIM stacked portion have a radiation control section having ... MIM stacked portion having a radiation control section having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a radiation control section having a radiation control section having a MIM stacked portion having a

[0018] In order to heat the heat radiation layer, the substrate, which reaches a high temperature, will emit radiation light. However, the platinum layer adjacent to the substrate in the MIM stack of the radiation control unit blocks the radiation light of the substrate and suppresses the radiation light of the substrate from passing through the interior of the radiation control unit. Therefore, it suppresses the influence of the radiation light of the substrate on the radiation light emitted from the radiation control unit.

[0019] Furthermore, since the radiation-emitting transparent oxide layer, which has a smaller refractive index than platinum and a larger refractive index than air, is arranged adjacent to the platinum layer located on the side of the radiation-emitting transparent oxide layer in the radiation control section (opposite to the side of the substrate), the reflectivity of the platinum layer located on the side of the radiation-emitting transparent oxide layer decreases, allowing the radiation emitted from the radiation control section to be well emitted to the outside.

[0020] Furthermore, the MIM stack in the radiation control section places the resonant transparent oxide layer between a pair of platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate, and the thickness of the resonant transparent oxide layer is 4... μ The wavelength below m is the thickness of the resonant wavelength, so the 4 nm wavelength in the radiation emitted from a platinum layer heated to a high temperature is... μ Wavelengths below 4 nm (i.e., narrow bands below the mid-infrared) are amplified through resonance, so the radiation emitted from the radiation control unit is at 4 nm. μ Narrow band wavelengths below 1 m (e.g., including wavelengths of 0.8 nm) μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ It has a large emissivity (radioactivity) in the narrow band of mid-infrared light below 4 nm, and in wavelengths greater than 4 nm... μ The wavelength of m (i.e., far-infrared light) has a small emissivity (radioactivity), resulting in the amplified 4 μ Radiation with a narrow band wavelength below m is emitted from the radioactive transparent oxide layer to the outside.

[0021] If explained further, MIM stands for Metal-Insulator-Metal. The MIM stack allows the 4... (The sentence is incomplete and requires more context to translate accurately.) μ Radiated light with wavelengths below 1 m is repeatedly reflected between platinum layers (within the transparent oxide layer for resonance) arranged along the stacking direction of the thermal radiation layer and the substrate, thus causing 4 μ Radiant light with wavelengths below m is amplified, and the amplified 4 μ Radiation with wavelengths below 1 m is emitted from the transparent oxide layer used for radiation to the outside.

[0022] That is, 4 μ Radiated light with wavelengths below 1 m is repeatedly reflected and amplified between platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate. μ A portion of the radiation light with wavelengths below 1 m passes through the side containing the radioactive transparent oxide layer and is emitted to the outside. As a result, the 4 m wavelength is amplified. μ Radiation with wavelengths below 1 m is emitted from the transparent oxide layer used for radiation to the outside.

[0023] In contrast, the radiation emitted from the platinum layer contains more than 4 μ The wavelength of m is emitted from the radioactive transparent oxide layer to the outside in a state where it is rarely amplified by resonance.

[0024] As a result, the radiation emitted from the transparent oxide layer to the outside is 4 μIt has a large emissivity (radioactivity) in narrow bands below 4 nm (i.e., narrow bands below the mid-infrared). μ The wavelength of m (i.e., the wavelength of far-infrared light) has a small emissivity (radioactivity).

[0025] It should also be noted that among the multiple platinum layers in the MIM stack, the platinum layer adjacent to the substrate needs to shield the substrate from radiation, while the other platinum layers need to allow some radiation to pass through. Therefore, the platinum layer adjacent to the substrate is formed thicker than the other platinum layers.

[0026] In this way, the thermal radiation layer amplifies the 4 μ Radiation with wavelengths below 1 m is emitted from the transparent oxide layer for radiation to the outside. Moreover, even when placed in air, it suppresses the deterioration of the radiation control unit and the substrate due to oxidation, thereby maintaining optical properties for a long time.

[0027] That is, the platinum layer in the MIM stack is formed of platinum. The standard Gibbs free energy of platinum is positive in all temperature ranges and does not oxidize in air, so it will not deteriorate due to oxidation even when placed in air.

[0028] In addition, the transparent oxide layer for radiation and the transparent oxide layer for resonance inhibit the permeation of oxygen in the air toward the substrate, so even if the substrate is formed of an oxidizable material, the substrate can be suppressed from deterioration due to oxidation for a long time.

[0029] Therefore, the thermal radiation layer can maintain its optical properties for a long time even when it is placed in the air.

[0030] Incidentally, if the platinum forming the platinum layer adjacent to the substrate is heated to a high temperature, it may flow and accumulate on the substrate. However, the transparent oxide layer for resonance plays a role in suppressing the movement of platinum. In addition, if the platinum forming the platinum layer adjacent to the presence side of the transparent oxide layer for radiation is heated to a high temperature, it may flow and accumulate on the transparent oxide layer for resonance. However, since the transparent oxide layer for radiation plays a role in suppressing the movement of platinum, the accumulation of platinum can be suppressed. From this perspective, the thermal radiation layer can also maintain its optical properties for a long time.

[0031] In summary, according to the features of the present invention, a thermal radiation light source can be provided, which can be configured to expose the substrate and the thermal radiation layer to the atmosphere, and, in 4 μ Narrow-band wavelengths below m have high emissivity and are greater than 4 μ The emissivity of wavelengths with wavelengths of m is small.

[0032] A further feature of the thermal radiation light source of the present invention is that the radiation control unit is configured to have a plurality of the above-mentioned MIM stacked portions.

[0033] That is, because it has multiple MIM stacks where the resonant transparent oxide layer is located between a pair of platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate, the amplification based on the resonance effect can be fully utilized, and the amplification can be appropriately increased by 4. μ Radiated light with wavelengths below m.

[0034] Incidentally, having multiple MIM stacks refers to having three or more platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate, with the resonant transparent oxide layer located between adjacent platinum layers.

[0035] It should also be noted that, for example, in a configuration where three platinum layers are arranged along the stacking direction of the thermal radiation layer and the substrate, and a transparent oxide layer for resonance is located between adjacent platinum layers, i.e., in a configuration with two MIM stacks, the radiated light is amplified not only by being reflected between adjacent platinum layers, but also by being reflected between platinum layers located at both ends of the stacking direction of the thermal radiation layer and the substrate.

[0036] That is, when three or more platinum layers are provided along the stacking direction of the thermal radiation layer and the substrate, the following function is achieved: in addition to causing the radiation light to be repeatedly reflected between adjacent platinum layers, the radiation light is also repeatedly reflected between platinum layers arranged in a form that sandwiches other platinum layers.

[0037] It should be noted that, in the case of multiple MIM stacks, by changing the resonant frequency of each MIM stack, the amplified 4 μ Radiation with wavelengths below 1 m, except for wavelengths of 0.8 m. μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ In addition to mid-infrared light below 1 nm, wavelengths as low as 0.4 nm can also be obtained. μ m or more and less than 0.8 μ Visible light with wavelengths of up to 0.4 nm can be obtained, and wavelengths less than 0.4 nm can also be obtained. μ m ultraviolet light.

[0038] In summary, further features of the thermal radiation light source according to the present invention can be appropriately enlarged by 4 μ Radiated light with wavelengths below m.

[0039] A further feature of the thermal radiation light source of the present invention is that a substrate bonding layer is laminated between the substrate and the platinum layer adjacent to the substrate in the radiation control section.

[0040] That is, since a substrate bonding layer is laminated between the substrate and the platinum layer adjacent to the substrate in the radiation control section, the radiation control section can be prevented from peeling off from the substrate when the radiation control section is heated by the substrate.

[0041] That is, since the thermal expansion coefficient of the substrate is different from that of the radiation control section which has multiple thin films stacked, the radiation control section may peel off from the substrate when the radiation control section is heated by the substrate. However, by using a substrate bonding layer to improve the adhesion between the substrate and the platinum layer adjacent to the substrate in the radiation control section, the peeling of the radiation control section from the substrate can be suppressed.

[0042] In summary, the further features of the thermal radiation light source according to the present invention can suppress the radiation control unit from peeling off from the substrate.

[0043] A further feature of the thermal radiation light source of the present invention is that: a platinum sealing layer is stacked between the platinum layer and the transparent oxide layer for resonance in the above-mentioned MIM stack, and between the transparent oxide layer for radiation and the platinum layer adjacent to the transparent oxide layer for radiation in the above-mentioned radiation control section.

[0044] That is, since the platinum bonding layer is provided between the platinum layer and the transparent oxide layer for resonance in the MIM stack, and between the transparent oxide layer for radiation and the platinum layer adjacent to the transparent oxide layer for radiation in the radiation control section, when the radiation control section is heated to a high temperature by the substrate, the flow and aggregation of the platinum layer in the MIM stack can be suppressed. Furthermore, the difference in thermal expansion coefficients can also suppress the peeling of the platinum layer from the transparent oxide layer for resonance, or the peeling of the transparent oxide layer for radiation from the platinum layer.

[0045] That is, because platinum has low adhesion to transparent oxide, when the radiation control section is heated to a high temperature by the substrate, the platinum layer adjacent to the transparent oxide layer for resonance or the transparent oxide layer for radiation may flow and accumulate. However, by stacking a platinum adhesion layer, the adhesion between the platinum layer adjacent to the transparent oxide layer for resonance or the platinum layer adjacent to the transparent oxide layer for radiation is improved. As a result, when the radiation control section is heated to a high temperature by the substrate, the flow and accumulation of platinum layer in the MIM stack can be suppressed, and the peeling of the platinum layer from the transparent oxide layer for resonance or the peeling of the transparent oxide layer for radiation from the platinum layer can also be suppressed.

[0046] In summary, according to a further feature of the thermal radiation light source of the present invention, when the radiation control section is heated to a high temperature by the substrate, the flow and accumulation of platinum layer in the MIM stack can be suppressed.

[0047] A further feature of the thermal radiation light source of the present invention is that the aforementioned substrate adhesive layer and the aforementioned platinum adhesive layer are formed of titanium.

[0048] That is, titanium can effectively improve the adhesion of platinum layers adjacent to the substrate to the substrate, or the adhesion of platinum layers adjacent to the transparent oxide layer for resonance to the transparent oxide layer for resonance, or the adhesion of platinum layers adjacent to the transparent oxide layer for radiation to the transparent oxide layer for radiation. Moreover, its melting point is as high as 1668°C, so when the radiation control section is heated to a high temperature by the substrate, the flow and accumulation of platinum layers in the MIM stack can be appropriately suppressed.

[0049] Incidentally, the titanium forming the substrate adhesive layer and the platinum adhesive layer can sometimes be slowly oxidized into titanium oxide when exposed to thermal radiation in the atmosphere. In other words, if a thermal radiation source is used in the atmosphere, the substrate adhesive layer and the platinum adhesive layer can be considered to be formed of titanium oxide.

[0050] However, not all of the titanium forming the substrate bonding layer and the platinum bonding layer is converted into titanium oxide. The titanium in the part that is bonded to the platinum layer is not oxidized and continues to be in the state of titanium bonded to the platinum layer (metallic state).

[0051] It should also be noted that the substrate adhesive layer and platinum adhesive layer formed from titanium are formed into a thin film in a light-transmitting manner. Then, the titanium that has formed into a thin film becomes titanium oxide. However, since titanium oxide is transparent, even if titanium becomes titanium oxide, it will not have an adverse effect on the performance of the heat radiation layer.

[0052] In summary, according to a further feature of the thermal radiation light source of the present invention, when the radiation control section is heated to a high temperature by the substrate, the flow and accumulation of platinum layer in the MIM stack can be suppressed.

[0053] A further feature of the thermal radiation light source of the present invention is that the transparent oxide forming the above-mentioned transparent oxide layer for resonance and the above-mentioned transparent oxide layer for radiation is aluminum oxide or titanium oxide.

[0054] That is, since aluminum oxide and titanium oxide are materials with low oxygen diffusion coefficients, by using aluminum oxide or titanium oxide as transparent oxides to form transparent oxide layers for radiation and transparent oxide layers for resonance, oxygen permeation in the atmosphere can be appropriately suppressed. Even if the substrate is formed of a material that can be oxidized, the surface of one side of the stacked radiation control section in the substrate can be appropriately prevented from deteriorating due to oxidation.

[0055] In summary, the further features of the thermal radiation light source according to the present invention can appropriately prevent the surface of one side of the stacked radiation control section in the substrate from deteriorating due to oxidation.

[0056] A further feature of the thermal radiation light source of the present invention is that the substrate is configured to generate heat by passing an electric current through it.

[0057] That is, since the substrate is constructed in a form that heats itself by passing electricity through it, the radiation control unit can be heated by passing electricity through the substrate. Therefore, there is no need to provide a special external heating unit for heating the substrate, thus simplifying the overall structure.

[0058] Incidentally, materials that generate heat through the conduction of electricity include metals such as Kanthal alloy and Nichrome alloy, which can be used to construct substrates.

[0059] In summary, further features of the thermal radiation light source according to the present invention can simplify the overall configuration.

[0060] A further feature of the thermal radiation light source of the present invention is that the substrate is configured to be heated by an external heating element.

[0061] That is, since the substrate is heated by an external heating element, various materials such as quartz (silicon dioxide) or sapphire can be used to construct the substrate.

[0062] That is, by using materials that do not oxidize, such as quartz (silicon dioxide) or sapphire, to form the substrate, the oxidation and deterioration of the substrate can be appropriately suppressed.

[0063] In summary, the further features of the thermal radiation light source according to the present invention can appropriately suppress the oxidative degradation of the substrate. Attached Figure Description

[0064] [ Figure 1 [ ] is a diagram showing the basic structure of a thermal radiation source.

[0065] [ Figure 2 [This is a table showing structural examples of the basic components of a thermal radiation source.]

[0066] [ Figure 3 [ ] is a graph showing the relationship between the structure of a thermal radiation source and the radiation spectrum.

[0067] [ Figure 4 [ ] is a diagram showing other forms in the basic structure of a thermal radiation source.

[0068] [ Figure 5 [ ] is a graph showing the relationship between other forms of the basic structure of a thermal radiation source and the radiation spectrum.

[0069] [ Figure 6 [This is a graph showing the relationship between the type of transparent oxide used as a thermal radiation source and the radiation spectrum.]

[0070] [ Figure 7[ ] is a diagram showing the specific composition of a thermal radiation source.

[0071] [ Figure 8 [ ] is a graph showing the changes in the transparent oxide layer used for resonance.

[0072] [ Figure 9 [ ] is a graph showing the relationship between the thickness of the platinum sealing layer and the radiation spectrum.

[0073] [ Figure 10 [ ] is a graph showing the relationship between the changes in the transparent oxide layer used for resonance and the radiation spectrum.

[0074] [ Figure 11 [ ] is a graph showing the relationship between the thickness of the first platinum layer and the radiation spectrum.

[0075] [ Figure 12 [ ] is a graph showing the relationship between the thickness of the second platinum layer and the radiation spectrum.

[0076] [ Figure 13 [ ] is a graph showing the relationship between the thickness of the second platinum layer and the radiation spectrum.

[0077] [ Figure 14 [ ] is a graph showing the relationship between the thickness of the transparent oxide layer used for resonance and the radiation spectrum.

[0078] [ Figure 15 [ ] is a graph showing the relationship between the thickness of the transparent oxide layer used for resonance and the radiation spectrum.

[0079] [ Figure 16 [ ] is a perspective view (three-dimensional view) showing the relationship between the thermal radiation source and the heating electrode.

[0080] [ Figure 17 [ ] is a perspective view showing the relationship between the thermal radiation source and the heating electrode.

[0081] [ Figure 18 [ ] is a slanted view showing the relationship between the thermal radiation source and the thermal radiator.

[0082] [ Figure 19 [ ] is a slanted view showing the relationship between the thermal radiation source and the high-temperature fluid source.

[0083] [ Figure 20 [ ] is a diagram showing the thermal radiation source of a reference example. Detailed Implementation

[0084] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0085] [Basic Components of a Thermal Radiation Source]

[0086] Figure 1This diagram shows the basic structure of a thermal radiation light source Q, which is composed of a thermal radiation layer N and a substrate K for heating the thermal radiation layer N.

[0087] The thermal radiation layer N is configured such that the radiation control section Na and the radiation transparent oxide layer Nb are stacked on the side closest to the substrate K in the order of radiation control section Na and radiation transparent oxide layer Nb formed of transparent oxide.

[0088] The radiation control unit Na is configured with a MIM stacked section M, wherein the MIM stacked section M places a transparent oxide layer R formed of transparent oxide between a pair of platinum layers P arranged along the stacking direction of the thermal radiation layer N and the substrate K.

[0089] The thickness of the transparent oxide layer R used for resonance is set to 4. μ The thickness of wavelengths below m is the resonant wavelength.

[0090] exist Figure 1 In the basic configuration of the thermal radiation source Q shown, the radiation control unit Na has one MIM stacked unit M.

[0091] That is, in the basic configuration of the thermal radiation light source Q, the platinum layer P constituting the MIM stacked portion M, the transparent oxide layer R for resonance and the platinum layer P, and the transparent oxide layer Nb for radiation are sequentially stacked on the upper part of the substrate K in the order described.

[0092] It should also be noted that, in the following description, the platinum layer P adjacent to the substrate K in the MIM stack is referred to as the first platinum layer P1, and the platinum layer P adjacent to the radiometric transparent oxide layer Nb in the MIM stack is referred to as the second platinum layer P2.

[0093] Moreover, it is configured such that by heating the thermal radiation layer N to a high temperature (e.g., 800°C) using the substrate K, the thermal radiation source Q emits radiation light H from the thermal radiation layer N.

[0094] Specifically, it is constructed in the manner of radiating light H, and as radiating light H, in 4 μ Narrow-band wavelengths below 1 m (e.g., including wavelengths of 0.8 nm). μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ It has a large emissivity (radioactivity) in the narrow band of mid-infrared light below 4 nm, and in wavelengths greater than 4 nm. μ The wavelength of m (i.e., far-infrared light) has a small emissivity (radioactivity).

[0095] That is, if the thermal radiation layer N is heated to a high temperature (e.g., 800°C) by the substrate K, the platinum layer P (first platinum layer P1 and second platinum layer P2) in the MIM stack of the radiation control unit Na emits radiation light, such as... Figure 3 As shown, the emissivity (radiance) of its radiated light (radiation from platinum) is in the range of 4. μ In wavelengths below 4 nm, there is a tendency to gradually increase towards shorter wavelengths, while in wavelengths greater than 4 nm... μ The value remains low within the wavelength of m.

[0096] Furthermore, since the thickness of the transparent oxide layer R for resonance in the MIM stack is 4 μ The thickness below the wavelength of the resonant wavelength is the thickness of the layer, so the radiation light of the platinum layer P (the first platinum layer P1 and the second platinum layer P2) in the MIM layer stack M contains 4 μ Wavelengths below 100 nm (i.e., narrow bands below the mid-infrared) are amplified through resonance, resulting in the radiation control unit Na at 4... μ Narrow-band wavelengths below 1 m (e.g., including wavelengths of 0.8 nm). μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ It has a large emissivity (radioactivity) in the narrow band of mid-infrared light below 4 nm, and in wavelengths greater than 4 nm... μ The wavelength of m (i.e., far-infrared light) has a small emissivity (radioactivity), resulting in the amplified 4 μ Radiation H with wavelengths below m is emitted from the radioactive transparent oxide layer Nb to the outside.

[0097] If explained further, MIM refers to metal-insulator-metal. The MIM stacked layer M transmits 4% of the radiant light emitted by the platinum layer P (the first platinum layer P1 and the second platinum layer P2). μ Radiation with wavelengths below m is repeatedly reflected between a pair of platinum layers P (the first platinum layer P1 and the second platinum layer P2) arranged along the stacking direction of the thermal radiation layer N and the substrate K, causing 4 μ Radiant light with wavelengths below m is amplified, and the amplified 4 μ Radiation with wavelengths below 1 m is emitted from the radioactive transparent oxide layer Nb to the outside.

[0098] That is, 4 μ Radiation with wavelengths below m is repeatedly reflected and amplified between platinum layers P (the first platinum layer P1 and the second platinum layer P2) arranged along the stacking direction of the thermal radiation layer N and the substrate K. μA portion of the radiation light with wavelengths below 1 m passes through the presence side of the radioactive transparent oxide layer Nb and is emitted to the outside from the radioactive transparent oxide layer Nb. As a result, the 4 nm wavelength is amplified. μ Radiation with wavelengths below 1 m is emitted from the radioactive transparent oxide layer Nb to the outside.

[0099] In contrast, the radiation emitted by platinum layer P (the first platinum layer P1 and the second platinum layer P2) contains more than 4% of the total radiation. μ Radiation with a wavelength of m is emitted from the radioactive transparent oxide layer to the outside with minimal amplification through resonance.

[0100] As a result, the radiation H emitted from the thermal radiation source Q (radiation light emitted from the transparent oxide layer Nb to the outside) at 4 μ It has a large emissivity (radioactivity) in narrow bands below 4 nm (i.e., narrow bands below the mid-infrared). μ The wavelength of m (i.e., the wavelength of far-infrared light) has a small emissivity (radioactivity).

[0101] However, in order to heat the thermal radiation layer N, radiation light is emitted from the substrate K, which has reached a high temperature. But the transmission of this radiation light to the radiation control section Na is blocked by the first platinum layer P1. In other words, the thickness of the first platinum layer P1 is the thickness that can block the radiation light from the substrate K.

[0102] In addition, since the transparent oxide layer Nb for radiation is a layer with a refractive index less than that of platinum and a refractive index greater than that of air, the reflectivity of the platinum layer P (the second platinum layer P2) located on the side where the transparent oxide layer Nb for radiation is present is reduced, which allows the radiation emitted from the radiation control unit Na to be well emitted to the outside.

[0103] It should also be noted that, in the platinum layers P (first platinum layer P1 and second platinum layer P2) of the MIM stack, the platinum layer P (first platinum layer P1) adjacent to the substrate K needs to block the radiation light from the substrate K, while the other platinum layers P (second platinum layer P2) need to allow some radiation light to pass through. Therefore, the platinum layer P (first platinum layer P1) adjacent to the substrate K is formed thicker than the other platinum layers P (second platinum layer P2). As a result, the radiation intensity of the platinum layer P (first platinum layer P1) adjacent to the substrate K in the platinum layers P (first platinum layer P1 and second platinum layer P2) is greater than that of the other platinum layers P (second platinum layer P2).

[0104] Incidentally, the thermal radiation light source Q of this invention is expected to have "4" characteristics. μ The emissivity increases below m, 0.8 μ m~4 μ The maximum emissivity between m (near-infrared to mid-infrared region) is over 90%, on the other hand, 4 μThe composition of far-infrared regions above m is characterized by small radiation peaks and peaks that do not have emissivity (hereinafter referred to as the rational composition).

[0105] [Explanation of basic structural examples]

[0106] Next, a structural example of the basic configuration of the thermal radiation source Q will be described. In the structural example described below, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is aluminum oxide (Al2O3). It should also be noted that any substrate K can be used; details of substrate K will be described later.

[0107] like Figure 2 As shown in the table, the structural examples described below are structures 1 through 4. It should also be noted that... Figure 2 In the table, substrate K is designated as layer No.1, first platinum layer P1 as layer No.2, transparent oxide layer R for resonance as layer No.3, second platinum layer P2 as layer No.4, and transparent oxide layer Nb for radiation as layer No.5.

[0108] like Figure 3 As shown, the thermal radiation source Q of structures 1 to 4 emits radiation light H, wherein the radiation light H includes a wavelength of 0.8. μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ It has a large emissivity (radioactivity) in the narrow band of mid-infrared light below 4 nm, and in wavelengths greater than 4 nm... μ The wavelength of m (i.e., far-infrared light) has a small emissivity (radioactivity).

[0109] Furthermore, when the thickness of the transparent oxide layer R used for resonance of layer No3 is relatively thin, the peak position of the emissivity becomes short-wavelength due to the short wavelength of the resonance frequency. When the thickness of the transparent oxide layer R used for resonance of layer No3 is relatively thick, the peak of the emissivity tends to shift to longer wavelengths due to the long wavelength of the resonance frequency.

[0110] Furthermore, when the thickness of the second platinum layer P2 in layer No.4 is relatively large, the peaks of the emissivity spectrum tend to become narrower, while when the thickness of the second platinum layer P2 in layer No.4 is relatively thin, the peaks of the emissivity spectrum tend to become wider.

[0111] Furthermore, the thicker the transparent oxide layer Nb for radiation in layer No.5, the more the spectrum of emissivity tends to shift towards longer wavelengths.

[0112] When the thermal radiation source Q is configured as described above, the suitable range for the film thickness of the first platinum layer P1 is, for example, 10 nm or more, and the suitable range for the film thickness of the second platinum layer P2 is, for example, 1.5 nm or more and 18 nm or less.

[0113] The appropriate range of film thickness for the first platinum layer P1 and the second platinum layer P2 is explained below.

[0114] Figure 11 Example: The relationship between the thickness of the first platinum layer P1 and the emissivity in the thermal radiation source Q of structure 2. When the thickness of the first platinum layer P1 varies from 5 to 150 nm, the peak emissivity does not exceed 90% when the thickness of the first platinum layer P1 is 5 nm, and exceeds 90% when the thickness is 10 nm.

[0115] Furthermore, if the thickness of the first platinum layer P1 increases, the radiation spectrum gradually stops changing, and becomes almost fixed from a thickness of approximately 60 nm. Thus, there is no upper limit to the specified thickness of the first platinum layer P1.

[0116] Based on the above results, a suitable range for the thickness of the first platinum layer P1 is, for example, 10 nm or more.

[0117] Figure 12 This example illustrates the relationship between the thickness (thickness) and emissivity of the second platinum layer P2. Wherein, Figure 12 Example: When the thickness of the first platinum layer P1 is set to 150 nm, the thickness of the resonance transparent oxide layer R is set to 140 nm, and the thickness of the radiation transparent oxide layer Nb is set to 75 nm, the radiation spectrum when the thickness of the second platinum layer P2 is changed to 1 nm, 1.5 nm, and 6 nm.

[0118] If the thickness of the second platinum layer P2 is greater than 1.5 nm, the peak of emissivity exceeds 90%; if it is less than 1.5 nm, the peak of emissivity will not exceed 90%.

[0119] Figure 13 This example illustrates the relationship between the thickness (thickness) and emissivity of the second platinum layer P2. Wherein, Figure 13 The radiation spectra are obtained when the thickness of the second platinum layer P2 is set to 6 nm, 15 nm, 18 nm, and 25 nm, respectively, with the thickness of the first platinum layer P1 set to 150 nm, the thickness of the resonance transparent oxide layer R set to 140 nm, and the thickness of the radiation transparent oxide layer Nb set to 100 nm.

[0120] When the thickness of the second platinum layer P2 is 19 nm, the peak of emissivity is 90%. If the thickness is greater than 19 nm, the peak of emissivity becomes smaller.

[0121] Based on the above results, a suitable range for the thickness of the second platinum layer P2 is, for example, 1.5 nm or more and 18 nm or less.

[0122] When the thermal radiation source Q has the above-described reasonable configuration, and the transparent oxide is aluminum oxide (Al2O3), with 4 μ The appropriate range for the thickness (film thickness) of the transparent oxide layer R used for resonance wavelengths below 1050 nm is 60 nm or more and 1050 nm or less.

[0123] The following explains the appropriate range of thickness (film thickness) of the transparent oxide layer R for resonance formed from aluminum oxide (Al2O3).

[0124] Figure 14 This is a graph showing the relationship between the thickness (film thickness) of the transparent oxide layer R used for resonance and the emissivity of the thermal radiation source Q. Among them, Figure 14 Examples are shown of the radiation spectra when the thickness of the first platinum layer P1 is set to 150 nm, the thickness of the second platinum layer P2 is set to 6.6 nm, and the thickness of the transparent oxide layer Nb for radiation is set to 94 nm, and the thickness of the transparent oxide layer R for resonance is changed to 40 nm, 60 nm, 80 nm, and 100 nm.

[0125] By this Figure 14 It can be seen that the lower limit of the thickness of the transparent oxide layer R used for resonance with an emissivity of over 90% at 800nm, where the emissivity reaches its peak, is 60nm.

[0126] Figure 15 This demonstrates the relationship between the thickness (film thickness) of the transparent oxide layer R used for resonance and the emissivity of the thermal radiation source Q. Among these, Figure 15 Examples are shown of the radiation spectra when the thickness of the first platinum layer P1 is set to 150 nm, the thickness of the second platinum layer P2 is set to 10 nm, and the thickness of the transparent oxide layer Nb for radiation is set to 100 nm, and the thickness of the transparent oxide layer R for resonance is changed to 800 nm, 1050 nm, and 1200 nm.

[0127] By this Figure 15 It can be seen that if the thickness of the transparent oxide layer R used for resonance is greater than 1050 nm, then a peak of emissivity will appear in the wavelength region (far-infrared region) longer than 4000 nm.

[0128] Based on the above results, when the transparent oxide is aluminum oxide (Al2O3), with 4 μ The appropriate range for the thickness (film thickness) of the transparent oxide layer R used for resonance wavelengths below 1050 nm is 60 nm or more and 1050 nm or less.

[0129] However, the appropriate range of thickness (film thickness) of the transparent oxide layer R used for resonance varies depending on the refractive index of the transparent oxide.

[0130] The lower limit of the suitable range is (the lower limit of the film thickness for each material (unit: nm)) = -30.4n + 108. It should be noted that n is the refractive index of each material.

[0131] Additionally, the upper limit of the suitable range is (the upper limit of the film thickness for each material (unit: nm)) = -600n + 2030. It should be noted that n is the refractive index of each material.

[0132] Incidentally, when the thermal radiation source Q is configured as described above, the suitable range for the film thickness (thickness) of the radiation-transparent oxide layer Nb of layer No5 is, for example, 50 nm or more and 500 nm or less.

[0133] It should also be noted that, as mentioned above, Figure 3 The radiation spectrum of platinum (platinum only) is shown. By comparing the radiation spectrum of this platinum (platinum only) with the radiation spectra of structures 1 to 4, it can be seen that the emissivity increases in the near-infrared to mid-infrared region, and the contrast between the parts with high emissivity and the parts with low emissivity increases.

[0134] [Other forms of basic components]

[0135] In the above basic configuration, the example shown is that the radiation control unit Na has one MIM stack M, but the radiation control unit Na may have multiple MIM stacks M.

[0136] It should also be noted that having multiple MIM stacks M refers to the following configuration: three or more platinum layers P are arranged along the stacking direction of the thermal radiation layer N and the substrate K, such that the resonant transparent oxide layer R is located between adjacent platinum layers P.

[0137] Figure 4 In the case where the radiation control unit Na has two MIM stacked units M, the thermal radiation source Q illustrated herein will be referred to as structure 5.

[0138] Structure 5 includes a first platinum layer P1 adjacent to the substrate K, a second platinum layer P2 adjacent to the radiometric transparent oxide layer Nb, and a third platinum layer P3 located between the first platinum layer P1 and the second platinum layer P2 as platinum layer P.

[0139] In addition, the transparent oxide layer R for resonance includes a first transparent oxide layer R1 for resonance located between the first platinum layer P1 and the third platinum layer P3, and a second transparent oxide layer R2 for resonance located between the second platinum layer P2 and the third platinum layer P3.

[0140] In structure 5, the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is aluminum oxide (Al2O3). It should also be noted that any substrate can be used for substrate K, and details of substrate K are described later.

[0141] Furthermore, a MIM stack M is formed by the first platinum layer P1, the third platinum layer P3, and the first resonant transparent oxide layer R1, and a MIM stack M is formed by the second platinum layer P2, the third platinum layer P3, and the second resonant transparent oxide layer R2. As a result, the radiation control unit Na has two MIM stacks M.

[0142] In structure 5, with the thickness of the first platinum layer P1 set to 150 nm, the thickness of the first resonant transparent oxide layer R1 set to 65 nm, the thickness of the third platinum layer P3 set to 8 nm, the thickness of the second resonant transparent oxide layer R2 set to 145 nm, the thickness of the second platinum layer P2 set to 5 nm, and the thickness of the radiometric transparent oxide layer Nb set to 72 nm, the radiation spectrum is shown below. Figure 5 .

[0143] It should also be noted that, in Figure 5 The radiation spectrum of structure 1 described above is also recorded in the text.

[0144] In structure 5, due to the change in the resonant frequencies of the two MIM stacked sections M, therefore, as Figure 5 As shown, even at a wavelength of 0.4... μ m or more and less than 0.8 μ The wavelength of visible light in m can also resonate, as an amplified 4 μ Radiation H with wavelengths below m can be obtained except for wavelengths of 0.8 m. μ m or more and less than 2.5 μ Near-infrared light with a wavelength of 2.5 m. μ m or more and 4 μ In addition to mid-infrared light below 1 nm, it also includes light with a wavelength of 0.4 nm. μ m or more and less than 0.8 μ Visible light with a wavelength of m, or wavelengths less than 0.4 nm. μ The ultraviolet radiation H of m.

[0145] [Regarding the categories of transparent oxides]

[0146] In the above-described basic configuration and other forms of the basic configuration of the thermal radiation source Q, the case in which the transparent oxide forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance is aluminum oxide (Al2O3) is exemplified. As the transparent oxide, tantalum pentoxide (Ta2O5), silicon dioxide (SiO2), niobium pentoxide (Nb2O5), magnesium oxide (MgO), titanium oxide (TiO2), hafnium oxide (HfO2), etc. can be used.

[0147] It should also be noted that aluminum oxide (Al2O3) and titanium oxide (TiO2) have low oxygen diffusion coefficients, making them particularly preferred as transparent oxides for forming the transparent oxide layer Nb for radiation and the transparent oxide layer R for resonance.

[0148] Figure 6 Examples of radiation spectra are given when the transparent oxides are different in the above basic configuration. Specifically, examples of radiation spectra are given when the thickness of the first platinum layer P1 is set to 150 nm, the thickness of the resonance transparent oxide layer R is set to 120 nm, the thickness of the second platinum layer P2 is set to 8 nm, and the thickness of the radiation transparent oxide layer Nb is set to 120 nm, so that the transparent oxides forming the radiation transparent oxide layer Nb and the resonance transparent oxide layer R are different.

[0149] like Figure 6 As shown, even when using tantalum pentoxide (Ta₂O₅), silicon dioxide (SiO₂), niobium pentoxide (Nb₂O₅), magnesium oxide (MgO), titanium oxide (TiO₂), and hafnium oxide (HfO₂) as the transparent oxides for forming the radioactive transparent oxide layer Nb and the resonant transparent oxide layer R, amplified 4 μ Radiant light H with wavelengths below m.

[0150] [Specific components of a thermal radiation source]

[0151] As a specific component of the thermal radiation source Q, such as Figure 7 As shown, the configuration is as follows: a substrate bonding layer S1 is stacked between the substrate K and the platinum layer P (first platinum layer P1) adjacent to the substrate K in the radiation control section Na. In addition, platinum bonding layers S2 are stacked between the platinum layer P (first platinum layer P1 and second platinum layer P2) in the MIM stacked section M and the resonance transparent oxide layer R, and between the radiation transparent oxide layer Nb and the platinum layer P (second platinum layer P2) adjacent to the radiation transparent oxide layer Nb in the radiation control section Na.

[0152] That is, since a substrate bonding layer S1 is stacked between the substrate K and the platinum layer P (first platinum layer P1) adjacent to the substrate K in the radiation control section Na, the radiation control section Na can be prevented from peeling off from the substrate K when it is heated by the substrate K.

[0153] That is, since the thermal expansion coefficient of the substrate K is significantly different from that of the radiation control section Na on which multiple thin films are stacked, the radiation control section Na may peel off from the substrate K when the substrate K is heated. However, by using the substrate bonding layer S1 to improve the adhesion between the substrate K and the platinum layer P (first platinum layer P1) adjacent to the substrate K in the radiation control section Na, the peeling off of the radiation control section Na from the substrate K can be suppressed.

[0154] Furthermore, since the platinum bonding layer S2 is provided between the platinum layer P (first platinum layer P1 and second platinum layer P2) in the MIM stack and the transparent oxide layer R for resonance, and between the transparent oxide layer Nb for radiation and the platinum layer P (second platinum layer P2) adjacent to the transparent oxide layer Nb for radiation in the radiation control section Na, when the radiation control section Na is heated to a high temperature by the substrate K, the flow and aggregation of the platinum layer P (first platinum layer P1 and second platinum layer P2) in the MIM stack is suppressed, and the peeling of the platinum layer P from the transparent oxide layer R for resonance or the peeling of the platinum layer P from the transparent oxide layer Nb for radiation can be suppressed.

[0155] That is, because platinum has low adhesion to transparent oxide, when the radiation control section Na is heated to a high temperature by the substrate K, the platinum layer P adjacent to the transparent oxide layer R for resonance or the platinum layer P adjacent to the transparent oxide layer Nb for radiation may flow and accumulate. However, by stacking the platinum adhesion layer S2, the adhesion of the platinum layer P adjacent to the transparent oxide layer R for resonance or the adhesion of the platinum layer P adjacent to the transparent oxide layer Nb for radiation is improved. As a result, when the radiation control section Na is heated to a high temperature by the substrate K, the flow and accumulation of platinum layer P in the MIM stacked section M is suppressed.

[0156] From the viewpoint of melting point and adhesion, titanium (Ti) or chromium (Cr) are superior materials for forming the substrate adhesive layer S1 and the platinum adhesive layer S2. Titanium (Ti) is particularly desirable. The following will describe the case where titanium (Ti) is used to form the substrate adhesive layer S1 and the platinum adhesive layer S2.

[0157] That is, since titanium (Ti) can effectively improve the adhesion of the platinum layer P (first platinum layer P1) adjacent to the substrate K to the substrate K, or the adhesion of the platinum layer P (first platinum layer P1 and second platinum layer P2) adjacent to the transparent oxide layer R for resonance to the transparent oxide layer R for resonance, or the adhesion of the platinum layer P (second platinum layer P2) adjacent to the transparent oxide layer Nb for radiation to the transparent oxide layer Nb for radiation, and its melting point is as high as 1668°C, when the radiation control section Na is heated to a high temperature by the substrate K, the flow and aggregation of the platinum layer P (first platinum layer P1 and second platinum layer P2) in the MIM stack can be appropriately suppressed.

[0158] [Thickness of the adhesive layer for the substrate]

[0159] If the substrate uses a sealing layer S1 that reaches a high temperature, the radiation will be greater than 4. μ The radiation light has a wavelength of m (i.e., far-infrared light), but since the radiation light emitted from the substrate adhesive layer S1 is blocked by the first platinum layer P1, there is no problem in this regard even if the thickness (film thickness) of the substrate adhesive layer S1 increases.

[0160] However, if the adhesive layer S1 of the substrate is too thick, when the radiation control section Na is heated to a high temperature by the substrate K, the titanium (Ti) will move around due to the heat, which may cause a phenomenon to occur on the surface of the side where the resonant transparent oxide layer R of the first platinum layer P1 is present. If this phenomenon occurs, the thermal radiation control structure of the radiation control section Na will be destroyed, and thus thermal radiation control will become difficult.

[0161] In addition, if the adhesive layer S1 of the substrate is too thin, it cannot accommodate the difference in thermal expansion rate between the radiation control section Na, which has multiple thin films, and the substrate K. When the radiation control section Na is heated to a high temperature by the substrate K, the radiation control section Na may peel off from the substrate K.

[0162] Based on this viewpoint, the thickness of the substrate bonding layer S1 (the thickness of titanium) is preferably above 2 nm and below 15 nm.

[0163] [Thickness of the platinum bonding layer]

[0164] The thickness (film thickness) of the platinum bonding layer S2 needs to be set from both optical and durability perspectives.

[0165] In other words, if the thickness (film thickness) of the platinum bonding layer S2 is too thick, it is optically disadvantageous. Specifically, if the platinum bonding layer S2 reaches a high temperature, the radiation will be greater than 4. μ The radiation light has a wavelength of m (i.e., far-infrared light). Therefore, if the thickness (film thickness) of the platinum sealing layer S2 is too thick, the intensity of the radiation light from the platinum sealing layer S2 will increase, and the intensity of the radiation light from the radiation control unit Na will be greater than 4. μ A low emissivity (radioactivity) at wavelengths of m (i.e., far-infrared light) can have adverse effects.

[0166] Furthermore, if the thickness (film thickness) of the platinum bonding layer S2 is too thick, it will block radiation light, so it is necessary to avoid making the platinum bonding layer S2 too thick. It should also be noted that if it becomes too thick, then... μ The peak of emissivity below m is below 90%.

[0167] However, the platinum bonding layer S2 does not bond the substrate K to the thin film, but rather bonds the thin films to each other. Therefore, even if it is thinner than the substrate bonding layer S1, it will still produce a bonding effect.

[0168] Based on this viewpoint, the thickness (film thickness) of the platinum bonding layer S2 is preferably above 0.1 nm and below 10 nm.

[0169] Figure 9 This is a graph showing the relationship between the thickness (film thickness) of the platinum bonding layer S2 and the emissivity (radioactivity) of the thermal radiation source Q.

[0170] It should also be noted that, Figure 9 The figure shows how the thickness (film thickness) of the platinum adhesive layer S2 changes when the thickness of the substrate bonding layer S1 is set to 7 nm, the thickness of the first platinum layer P1 is set to 150 nm, the thickness of the resonance transparent oxide layer is set to 120 nm, the thickness of the second platinum layer P2 is set to 6 nm, and the thickness of the radiation transparent oxide layer Nb is set to 120 nm.

[0171] Examine the Figure 9 It can be seen that the thicker the platinum bonding layer S2 (film thickness), the longer it is than 4... μ The more far-infrared light is emitted on the wavelength side of m, the more it increases.

[0172] [On the oxidation of titanium]

[0173] The titanium (Ti) forming the substrate bonding layer S1 and the platinum bonding layer S2 is very likely to be slowly oxidized into titanium oxide (TiO2) when exposed to thermal radiation light source Q in the atmosphere. In other words, under the condition of using thermal radiation light source Q in the atmosphere, the substrate bonding layer S1 and the platinum bonding layer S2 can be regarded as being formed of titanium oxide (TiO2).

[0174] However, as Figure 8 As shown, not all of the titanium forming the platinum bonding layer S2 is converted into titanium oxide. The titanium in the part that is bonded to the platinum layer P (the second platinum layer P2) is not oxidized and continues to be in the state of titanium bonded to the platinum layer P (the second platinum layer P2) (metallic state).

[0175] Although the illustration is omitted, the titanium forming the substrate bonding layer S1 is not entirely converted into titanium oxide. The titanium in the part that is bonded to the platinum layer P (first platinum layer P1) is not oxidized and continues to be in the state of titanium bonded to the platinum layer P (first platinum layer P1) (metallic state).

[0176] That is, the titanium forming the substrate bonding layer S1 and the platinum bonding layer S2 is not completely transformed into titanium oxide. The titanium in the part bonded to the platinum layer P is not oxidized and continues to be in the state of titanium bonded to the platinum layer P, and continues to perform its function as the substrate bonding layer S1 and the platinum bonding layer S2.

[0177] This can be explained as follows: Because the standard Gibbs energy change of platinum (Pt) is +200 kJ / mol / O2, it does not react with oxygen (chemical reactions proceed in the direction of a negative Gibbs energy change. A positive Gibbs energy change means no reaction has occurred). This means that, due to the binding energy, it is difficult to use oxides as a bonding layer for platinum (Pt). Therefore, if titanium is oxidized to titanium oxide, there is a concern that it will not function as a bonding layer for platinum (Pt). However, even if titanium oxidizes, the titanium at the interface with platinum (Pt) maintains its bond with platinum, thus continuing to function as both the substrate bonding layer S1 and the platinum bonding layer S2.

[0178] Incidentally, the substrate adhesive layer S1 and the platinum adhesive layer S2 formed by titanium are formed into a thin film in a light-transmitting manner. Then, the titanium in the thin film state becomes titanium oxide. However, since titanium oxide is transparent, even if titanium becomes titanium oxide, it will not have an adverse effect on the performance of the heat radiation layer N.

[0179] It should also be noted that if the materials forming the substrate bonding layer S1 and the platinum bonding layer S2 are oxidized, chromium (Cr) turns black after oxidation. Therefore, chromium, which turns black after oxidation, is not suitable as a bonding layer from the point of view of radiation control. Titanium (Ti), which forms transparent titanium oxide (TiO2) after oxidation, is superior from the point of view of radiation control.

[0180] However, it is believed that as long as the titanium (Ti) in the platinum bonding layer S2 oxidizes over time, even if the platinum bonding layer S2 is relatively thick, it will still be close to the desired oxidation state. Figure 8 Thermal radiation is controlled when the film thickness is relatively thin. However, when the film thickness is relatively thick, as the radiation control section Na is heated to a high temperature by the substrate K, the titanium (Ti) moves due to the heat, potentially causing a phenomenon that occurs on the surface of the second platinum layer P2. If this phenomenon occurs, the thermal radiation control structure of the radiation control section Na is disrupted, making thermal radiation control more difficult. In particular, since the platinum in the second platinum layer P2 is relatively thin, the movement of titanium (Ti) has a significant impact on the disruption of the thermal radiation control structure.

[0181] Therefore, the thickness (film thickness) of the platinum bonding layer S2 is preferably around sub-nm (less than 1nm).

[0182] [Regarding the temporal changes of thermal radiation sources]

[0183] Figure 10 It is a graph showing the time-dependent changes in the thermal radiation spectrum of an actual thermal radiation source Q after it is heated to 800°C in the atmosphere.

[0184] Incidentally, Figure 10This is an example of a thermal radiation spectrum of a thermal radiation source Q when sapphire is used in substrate K, and the thickness of substrate bonding layer S1 is set to 7 nm, the thickness of first platinum layer P1 is set to 150 nm, the thickness of resonance transparent oxide layer is set to 120 nm, the thickness of second platinum layer P2 is set to 6 nm, the thickness of radiation transparent oxide layer Nb is set to 120 nm, and the thickness of platinum bonding layer S2 is set to 0.5 nm.

[0185] It should be noted that, as Figure 20 As shown, although it includes a substrate K, a substrate bonding layer S1, a first platinum layer P1, a platinum bonding layer S2, a resonant transparent oxide layer R, and a second platinum layer P2, if the platinum bonding layer S2 and the radioactive transparent oxide layer Nb on the surface opposite to the presence of the radioactive transparent oxide layer Nb in the second platinum layer P2 are omitted, the platinum (Pt) in the second platinum layer P2 will accumulate and scatter light during heating, and it will be unable to properly emit radioactive light.

[0186] like Figure 10 As shown, the thermal radiation spectrum after heating for 120 hours (5 days) is roughly the same as that after heating for 24 hours (1 day).

[0187] The thermal radiation spectrum immediately after film formation differs from that after heating for 24 hours and 120 hours. This is believed to be because heating increases the crystallinity of alumina (Al2O3) or platinum (Pt).

[0188] The theoretical (calculated) thermal radiation spectrum is obtained by calculation using the optical constants of highly crystalline alumina (Al2O3).

[0189] The thermal radiation spectrum immediately after film formation deviates from the theoretical (calculated) value, but the thermal radiation spectrum after heating becomes very close to the theoretical (calculated) value. Therefore, it is believed that the crystallinity of alumina (Al2O3) or platinum (Pt) is improved by heating, and thus the optical constants of alumina (Al2O3) or platinum (Pt) are close to the theoretical values.

[0190] As shown in the results above, the thermal radiation light source Q of the present invention is a thermal radiation light source that can be used by heating to about 800°C in the atmosphere.

[0191] It should also be noted that the melting points of the constituent materials of the thermal radiation light source Q of the present invention are as follows: platinum (Pt) is 1768°C, aluminum oxide (Al2O3) is 2072°C, titanium (Ti) is 1668°C, and titanium oxide (TiO2) is 1843°C. Although it also depends on the melting point of the substrate K, the thermal radiation layer N of the thermal radiation light source Q of the present invention can withstand a temperature of about 1400°C.

[0192] [About the substrate]

[0193] The thermal radiation of the substrate K, which reaches a high temperature, is blocked by the first platinum layer P1. Since the radiation control part Na does not pass through, various materials such as quartz (SiO2), sapphire, stainless steel (SUS), Kanthal, nickel-chromium alloy, aluminum, and silicon can be used as the material (base material) for the substrate K.

[0194] There is no problem when using an oxide-based substrate K, but when using a metal-based substrate K, oxidation degradation of the substrate K becomes a problem when it is heated in the atmosphere. However, due to the presence of a transparent oxide layer R for resonance and a transparent oxide layer Nb for radiation, as described above, oxidation degradation of the surface on the side where the thermal radiation layer N is present in the substrate K is prevented.

[0195] It should also be noted that the surface of the side containing the thermal radiation layer N in the substrate K forms a mirror surface to the extent that diffuse reflection does not occur.

[0196] The substrate K can be configured to generate heat by itself when energized, or it can be configured to be heated by an external heating element U.

[0197] That is, when the substrate K is made of materials such as Kanthal or nickel-chromium alloy that generate heat when electricity is applied, the substrate K can be constructed in a form that generates heat by itself when electricity is applied.

[0198] When the substrate K is formed of materials such as quartz (SiO2), sapphire, or stainless steel (SUS), such as Figures 16-19 As shown, it is configured to be heated by an external heating element U.

[0199] Figure 16 and Figure 17 In the case where the external heating unit U is configured as a plate-shaped heating electrode Ud with a heating wire that generates heat when energized, the substrate K of the thermal radiation source Q and the heating electrode Ud are fitted together in a close manner.

[0200] It should also be noted that, Figure 17 This refers to the case where a thermal radiation source Q is installed on one side of the heating electrode Ud. Figure 16 An example is shown where thermal radiation sources Q are arranged on both sides of the heating electrode Ud.

[0201] Figure 18 In the case where the external heating part U is configured as a thermal radiation source Ug that emits thermal radiation light G with uncontrolled wavelength, the substrate K of the thermal radiation source Q is arranged opposite to the thermal radiation source Ug.

[0202] Figure 19In the case where the external heating unit U is configured as a fluid supply source Ut that supplies high-temperature fluid T, the substrate K of the thermal radiation light source Q is arranged opposite to the fluid supply source Ut.

[0203] [Example of a modified adhesive layer for a substrate]

[0204] As mentioned above, the substrate adhesive layer S1 is made of titanium (Ti), but its composition needs to be slightly modified depending on the type of material used to form the substrate K.

[0205] When the material forming the substrate K is sapphire or aluminum oxide (Al2O3), as described above, the substrate bonding layer S1 is composed only of titanium (Ti).

[0206] When the material forming the substrate K is quartz (SiO2), the substrate bonding layer S1 can be made of titanium (Ti), or it can be a stacked structure of titanium (Ti) and aluminum oxide (Al2O3). That is, a structure can be formed by stacking the first platinum layer P1 / titanium (Ti) / aluminum oxide (Al2O3) (30nm) / substrate K in that order.

[0207] When the material constituting the substrate K is stainless steel (SUS), Kanthal, nickel-chromium alloy, aluminum, or silicon, a configuration can be formed by stacking the first platinum layer P1 / titanium (Ti) / aluminum oxide (Al2O3) (30nm) / substrate K in that order, or by stacking the first platinum layer P1 / titanium (Ti) / aluminum oxide (Al2O3) (30nm) / hafnium oxide (HfO2) / substrate K in that order.

[0208] That is, when the substrate K is a metal or a semiconductor, the first platinum layer P1 / titanium (Ti) reacts with the substrate K to alloy, which may make it impossible to control radiation. Therefore, from the viewpoint of preventing alloying, the oxide layer can be placed between the substrate K and the titanium (Ti).

[0209] [Other Implementation Methods]

[0210] Other implementation methods are listed below.

[0211] (1) In the above embodiment, even if oxidation occurs on the back side opposite to one side of the stacked thermal radiation layer N in the substrate K, as long as the substrate K is thick, it will not have an adverse effect on the thermal radiation layer N. In view of this, although a state is formed in which the back side opposite to one side of the stacked thermal radiation layer N in the substrate K is exposed, an anti-oxidation film that inhibits oxidation can be stacked on the back side.

[0212] (2) In the above embodiments, the radiation control unit Na is shown to have one MIM stacked portion M or two MIM stacked portions M, but the radiation control unit Na may be implemented in a form having three or more MIM stacked portions M.

[0213] It should be noted that as long as the configurations disclosed in the above embodiments (including other embodiments, the same below) do not contradict each other, they can be combined with the configurations disclosed in other embodiments. In addition, the embodiments disclosed in this specification are only illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope without departing from the purpose of the present invention.

[0214] Symbol Explanation

[0215] K: substrate;

[0216] N: Thermal radiation layer;

[0217] Na: Radiation Control Department;

[0218] Nb: Transparent oxide layer for radioactive applications;

[0219] M: MIM stack-up;

[0220] P: Platinum layer;

[0221] R: Transparent oxide layer for resonance;

[0222] S1: Adhesive layer for substrate;

[0223] S2: Platinum sealing layer.

Claims

1. A thermal radiation light source, which is a thermal radiation light source having a thermal radiation layer and a substrate for heating the thermal radiation layer stacked together. The aforementioned thermal radiation layer is configured such that the radiation control section having a MIM stack and the radiation-emitting transparent oxide layer formed of transparent oxide are stacked in such a manner that the radiation control section having a MIM stack and the radiation-emitting transparent oxide layer are located on one side close to the substrate, wherein the MIM stack places the resonance-emitting transparent oxide layer formed of transparent oxide between a pair of platinum layers arranged along the stacking direction of the thermal radiation layer and the substrate. The thickness of the aforementioned transparent oxide layer for resonance is the thickness at wavelengths below 4 μm that are used for resonance. By providing three or more platinum layers arranged along the stacking direction of the aforementioned thermal radiation layer and the aforementioned substrate, and placing the aforementioned resonant transparent oxide layer between adjacent platinum layers, the aforementioned radiation control unit is configured to have a plurality of aforementioned MIM stacked portions.

2. The thermal radiation light source according to claim 1, wherein, An adhesive layer for the substrate is laminated between the aforementioned substrate and the platinum layer adjacent to the aforementioned substrate in the aforementioned radiation control section.

3. The thermal radiation light source according to claim 2, wherein, A platinum sealing layer is stacked between the platinum layer and the transparent oxide layer for resonance in the MIM stack, and between the transparent oxide layer for radiation and the platinum layer adjacent to the transparent oxide layer for radiation in the radiation control section.

4. The thermal radiation light source according to claim 3, wherein, The aforementioned adhesive layer for the substrate and the aforementioned adhesive layer for platinum are formed of titanium.

5. The thermal radiation light source according to any one of claims 1 to 4, wherein, The transparent oxides forming the above-mentioned transparent oxide layer for resonance and the above-mentioned transparent oxide layer for radiation are aluminum oxide or titanium oxide.

6. The thermal radiation light source according to any one of claims 1 to 4, wherein, The aforementioned substrate is configured to generate heat by itself when energized.

7. The thermal radiation light source according to any one of claims 1 to 4, wherein, The aforementioned substrate is configured to be heated using an external heating element.

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