US 11,914,179 B2
Radiative cooling optical filter, its preparing method and application
Weidong Shen, Zhejiang (CN); Huaxin Yuan, Zhejiang (CN); Chenying Yang, Zhejiang (CN); Xiaowen Zheng, Zhejiang (CN); Wen Mu, Zhejiang (CN); Zhen Wang, Zhejiang (CN); Wenjia Yuan, Zhejiang (CN); and Yueguang Zhang, Zhejiang (CN)
Assigned to ZHEJIANG UNIVERSITY, Zhejiang (CN)
Appl. No. 17/263,161
Filed by ZHEJIANG UNIVERSITY, Zhejiang (CN)
PCT Filed Jan. 18, 2019, PCT No. PCT/CN2019/072320
§ 371(c)(1), (2) Date Jan. 26, 2021,
PCT Pub. No. WO2020/024566, PCT Pub. Date Feb. 6, 2020.
Claims priority of application No. 201810882085.9 (CN), filed on Aug. 3, 2018.
Prior Publication US 2021/0191017 A1, Jun. 24, 2021
Int. Cl. G02B 5/26 (2006.01); G02B 7/00 (2021.01)
CPC G02B 5/26 (2013.01) [G02B 7/008 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A radiative cooling optical filter, comprising a substrate, wherein
one side of the substrate is polished, a rough side of the substrate is provided with a metal reflective layer, a polished side of the substrate is subsequently provided with an intermediate layer and a top layer,
the intermediate layer comprises alternatingly arranged layers A and layers B, thickness of each layer A and layer B is 50-400 nm respectively,
a material of the layer A is silicon dioxide or aluminum oxide, and a material of the layer B is titanium dioxide, silicon nitride or silicon carbide,
or, the material of the layer A is titanium dioxide or aluminum oxide, and the material of the layer B is silicon dioxide, silicon nitride or silicon carbide,
a material of the top layer is ytterbium fluoride, yttrium fluoride or zinc sulfide,
the intermediate layer and the top layer jointly constitute a multi-resonant absorption enhancer in an atmospheric transparent window.