Nonspherical photonic scatterers and design criterion for efficient passive daytime radiative cooling  

作　　者：Xinping ZHANG Tairong KANG Fuqiang WANG Xiang LI Hongliang YI 

机构地区：[1]School of Energy Science and Engineering,Harbin Institute of Technology,Harbin 150001,China [2]College of New Energy,Harbin Institute of Technology at Weihai,Weihai 264209,China [3]Construction Eco-Environmental Protection Technology Co.,Ltd.,Suzhou 215123,China

出　　处：《Science China(Technological Sciences)》2025年第2期1-14,共14页中国科学(技术科学英文版)

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.52076064,52211530089);the Fundamental Research Funds for the Central Universities(Grant No.HIT.DZJJ.2023095);the National Key Research and Development Program of China(Grant No.2018YFA0702300);Taishan Scholar Foundation of Shandong Province(Grant No.tsqn201812105).

摘　　要：Passive daytime radiative cooling(PDRC)exhibits efficient cooling performance to reduce global fossil energy consumption and has attracted enormous interest.An efficient PDRC technology for achieving daytime subambient cooling is supposed to exhibit ultra-high solar reflectivity and infrared emissivity within atmospheric windows,among which ultra-high solar reflectivity is the principal property.In most PDRC technologies,spherical particles are selected as scatterers to achieve high solar reflectivity because the Mie scattering effect of spherical scatterers can provide a high scattering efficiency.However,the weak backward scattering of spherical scatterers remains a drawback.In this study,several nonspherical scatterers with strong backward scattering are introduced and researched systematically.The numerical analysis results indicate that pyramidal scatterers provide the strongest backward scattering and square/circular scatterers exhibit the highest scattering efficiency.Besides,by considering scattering efficiency and asymmetry factor comprehensively,a dimensionless evaluation parameter is proposed,which can be employed as a quantitative design criterion to achieve the optimal-object-oriented designing of superior scatterers.This work can provide an innovative strategy for designing efficient passive daytime radiative cooling materials.

关 键 词：radiative cooling nonspherical scatterers solar reflectivity backward scattering design criterion 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]