KR-20260064469-A - Multilayer Photothermal Substrate and Fabrication Method Thereof

Abstract

The present invention relates to a multilayer photothermal device and a method for manufacturing the same. More specifically, the multilayer photothermal device comprises a multilayer light-absorbing structure formed on a transparent substrate, wherein the first metal layer is composed of non-uniformly distributed metal nanoclusters that induce localized surface plasmon resonance, an insulating layer that controls optical interference conditions, and a second metal layer capable of inducing a photothermal effect. The multilayer photothermal device has high absorbance and high-efficiency photothermal effects across the entire visible light range.

Inventors

• 정기훈
• 정혜정
• 유은실

Assignees

• 한국과학기술원

Dates

Publication Date

20260507

Application Date

20250613

Priority Date

20241030

Claims (6)

1. A photothermal element comprising a multilayer light-absorbing structure formed on a transparent substrate (100), wherein the multilayer light-absorbing structure comprises the following: A first metal layer (200) comprising a metal nanostructure formed on the above-mentioned transparent substrate; An insulating layer (300) formed on the first metal layer; and A second metal layer (400) made of a continuous metal film formed on the insulating layer.
2. A photothermal device according to claim 1, characterized in that the metal nanostructure is selected from one or more of the group consisting of metal nanoparticles, metal nanofilms, metal nanofibers, and amorphous metal nanoclusters.
3. A photothermal element according to claim 1, characterized in that the metal of the first metal layer and the second metal layer is a conductive metal or a metal alloy.
4. A photothermal element according to claim 1, characterized in that the insulating layer is selected from one or more of the group consisting of SiO2 , TiO2 , Al2O3 , MgF2 , Si3N4 , and a polymer .
5. A photothermal element according to claim 3, characterized in that the metal is selected from one or more of the group consisting of gold, silver, aluminum, copper, platinum, and tungsten.
6. A method for manufacturing a photothermal element according to any one of claims 1 to 5, comprising the following steps: (a) A step of forming a first metal layer comprising metal nanostructures fabricated by depositing or heat-treating a metal on a transparent substrate; (b) a step of forming an insulating layer on the first metal layer; and (c) A step of forming a second metal layer comprising a continuous metal film on the insulating layer.

Description

Multilayer Photothermal Substrate and Fabrication Method Thereof The present invention relates to a multilayer photothermal device and a method for manufacturing the same, and more specifically, to a multilayer photothermal device and a method for manufacturing the same comprising a multilayer light-absorbing structure having a first metal layer composed of a non-uniformly distributed aggregate metal nanostructure that induces localized surface plasmon resonance on a transparent substrate, an insulating layer that controls optical interference conditions, and a second metal layer that can induce a photothermal effect. With growing interest in environmental issues, the development of pollution-free renewable energy—which captures energy that would otherwise be transformed or lost in nature and converts it into usable energy—is actively underway. Consequently, there is a focus on securing sustainable, eco-friendly energy sources, with solar energy receiving significant attention. In this context, achieving the highest efficiency in photothermal energy requires a light absorber that efficiently absorbs solar energy and converts it into heat. Meanwhile, thermoelectric devices utilize the thermoelectric effect, in which holes or free electrons flow from a high-temperature region to a low-temperature region to generate an electric current when a temperature difference occurs within the thermoelectric material and the temperature difference is reduced to return to the initial state. By utilizing this effect to check the output value of the thermoelectric device, the electrical energy generation efficiency can be measured. Light absorbers have been studied from three perspectives: high light absorption, efficient photothermal conversion, and low thermal radiation; however, the transfer of generated heat has not been investigated. Therefore, there is a growing need for a photothermal transfer layer capable of transferring generated heat to a specific location by imparting directionality to it. Light absorbers are materials that selectively absorb sunlight in specific spectral regions and convert light into heat through a photothermal conversion process. However, a problem exists in that efficiency decreases as the temperature rises and radiant heat is emitted during the photothermal conversion. Heat transfer materials possess high thermal conductivity, thermal diffusivity, and low specific heat to transfer externally obtained thermal energy to a target. Conventional carbon-based materials used as heat transfer materials have poor efficiency due to a large amount of heat radiated in the infrared region. Korean Patent Publication No. 10-2024-0096370 discloses a photothermal nanostructure device comprising a substrate having a first thermal conductivity and a light absorption layer, an insulating layer, and an anti-reflection layer formed thereon, wherein a nanostructure is formed on the surface of a silicon substrate to improve the light absorption rate, heat loss of the substrate is suppressed through an insulating layer with low thermal conductivity, and an anti-reflection layer is additionally included to reduce interfacial reflection. However, since the aforementioned prior art relies on the etched silicon substrate itself to form the light absorption layer, it has low flexibility in substrate material and structural design. Furthermore, because it does not incorporate precise optical design elements such as plasmonic resonance, multilayer interference, and nanocluster-based light trapping technology for enhancing light absorption, it has limitations in being utilized in various photothermal applications. FIG. 1 is a cross-sectional view illustrating a multilayer photothermal element structure according to one embodiment of the present invention. FIG. 2 is a diagram illustrating a method for fabricating a plasmonic nanocavity photothermal substrate (a spontaneous gold cluster-based plasmonic nanocavity structure) according to one embodiment of the present invention. FIG. 3 is a diagram illustrating a method for fabricating a plasmonic nanocavity photothermal substrate (a heat-treatable gold cluster-based plasmonic nanocavity structure) according to one embodiment of the present invention. FIG. 4 is a scanning electron microscope (SEM) image of a plasmonic nanocavity photothermal substrate (spontaneous gold cluster-based plasmonic nanocavity structure) according to one embodiment of the present invention ((a) spontaneous gold cluster, (b) plasmonic nanocavity structure). FIG. 5 is a scanning electron microscope (SEM) image of a plasmonic nanocavity photothermal substrate (thermal-treated gold cluster-based plasmonic nanocavity structure) according to one embodiment of the present invention ((a) thermal-treated gold cluster, (b) plasmonic nanocavity structure). FIG. 6 is a spectrum of absorbance in the visible light region of a plasmonic nanocavity photothermal substrate (spontaneous gold cluster-based plasmonic nan