Radiative cooling optical filter, its preparing method and application

US11914179B2 · kind B2 · utility

Assignee

• ZHEJIANG UNIVERSITY · CN

Inventors

• Weidong Shen · Zhejiang, CN
• Huaxin Yuan · Zhejiang, CN
• Chenying Yang · Seattle, US
• Xiaowen Zheng · Zhejiang, CN
• Wen Mu · Singapore, SG
• Zhen Wang · Beijing, CN
• Wenjia YUAN · Zhejiang, CN
• Yueguang Zhang · Hangzhou City, CN

Key dates

• Filing date: Jan 18, 2019
• Grant date: Feb 27, 2024
• Expiry date: Nov 29, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B7/008
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

This disclosure discloses a radiative cooling optical filter, comprising a substrate. One side of the substrate is polished, and the rough side of the substrate is provided with a metal reflective layer. The polished side of the substrate is subsequently provided with the intermediate layers and a top layer. The intermediate layer comprises alternatingly arranged layers A and layers B. The thickness of each layer A and layer B is 50-400 nm. The material of the layer A is silicon dioxide or aluminum oxide, and the material of the layer B is titanium dioxide, silicon nitride or silicon carbide. The 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 the atmospheric transparent window.