Selective absorption emitter

Abstract

The invention discloses a selective absorption emitter. The selective absorption emitter comprises a substrate, a metal film covering the substrate and a cell array arranged on the metal film, whereinthe unit array is composed of a plurality of basic units which are arranged at intervals and have the same shape and the same size, each basic unit is composed of a plurality of stacks which are sequentially stacked from top to bottom, each stack comprises a metal layer and a dielectric layer located on the lower side of the metal layer or two dielectric layers with different refractive indexes,and the included angle between the side surfaces of the basic units and the normal of the substrate is minus 80-80 degrees. The selective absorption emitter is a broadband absorption emitter with wavelength selectivity. The correlation degree between the working wavelength of the emitter and the diameter or the length of the tops and the bottoms of the basic units in the unit array is small, the requirement on the precision of preparation technology is low, when the working wavelength of the emitter ranges from 8 microns to 13 microns, and high absorption and high emissivity are achieved, theemitter can be used for passive radiation refrigeration, and the required absorption characteristics can be obtained in other wavelength ranges by changing array design parameters.

Description

technical field [0001] The invention belongs to the field of photoelectric and photothermal functional materials and devices, and in particular relates to a selective absorption emitter. Background technique [0002] Kirchhoff's thermal radiation law is used to describe the relationship between the emissivity and absorptivity of an object, which states that at the same temperature, the ratio of the monochromatic radiation flux density to the monochromatic absorptivity of different objects for the same wavelength is the same as the The monochromatic radiation flux density of a black body at the same wavelength is equal at temperature, that is, the absorptivity is equal to the emissivity. It shows that the more radiating an object is, the more absorbing it is, and vice versa. [0003] Thermal radiation is a non-contact heat transfer method, which relies on electromagnetic wave radiation to achieve energy transfer between hot and cold objects, even in a vacuum. In 2014, the r...

AI Technical Summary

Problems solved by technology

In 2015, Australia's Min Gu research team reported in Advanced Optical Materials (volume 3, page 1047) an infrared thermal emitter based on a hyperbolic metamaterial, which has an average emissivity of 0.8 in the atmospheric transparent window, higher than 0.67 for the multilayer film system, however, the researchers did not test the passive radiative cooling properties of the metamaterial

In fact, although the use of more materials will bring greater design freedom, it will also be limited by the type of materials, and the design dielectric constant may not have a corresponding material in nature, and it may further increase the experimental equipment. complexity and cost of manufacturing

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