Designing Mesoporous Photonic Structures for High-Performance Passive Daytime Radiative Cooling

Meijie Chen; Dan Pang; Jyotirmoy Mandal; Xingyu Chen; Hongjie Yan; Yurong He; Nanfang Yu; Yuan Yang

doi:10.1021/acs.nanolett.0c04241

Designing Mesoporous Photonic Structures for High-Performance Passive Daytime Radiative Cooling

Nano Lett. 2021 Feb 10;21(3):1412-1418. doi: 10.1021/acs.nanolett.0c04241. Epub 2021 Feb 1.

Authors

Meijie Chen^{1

2}, Dan Pang¹, Jyotirmoy Mandal³, Xingyu Chen¹, Hongjie Yan¹, Yurong He⁴, Nanfang Yu², Yuan Yang²

Affiliations

¹ School of Energy Science and Engineering, Central South University, Changsha 410083, China.
² Program of Materials Science and Engineering, Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, United States.
³ Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States.
⁴ School of Energy Science and Engineering, Harbin Institution of Technology, Harbin 180001, China.

PMID: 33524258
DOI: 10.1021/acs.nanolett.0c04241

Abstract

Passive daytime radiative cooling (PDRC) has drawn significant attention recently for electricity-free cooling. Porous polymers are attractive for PDRC since they have excellent performance and scalability. A fundamental question remaining is how PDRC performance depends on pore properties (e.g., radius, porosity), which is critical to guiding future structure designs. In this work, optical simulations are carried out to answer this question, and effects of pore size, porosity, and thickness are studied. We find that mixed nanopores (e.g., radii of 100 and 200 nm) have a much higher solar reflectance R̅_solar (0.951) than the single-sized pores (0.811) at a thickness of 300 μm. With an Al substrate underneath, R̅_solar, thermal emittance ε̅_LWIR, and net cooling power P_cool reach 0.980, 0.984, and 72 W/m², respectively, under a semihumid atmospheric condition. These simulation results provide a guide for designing high-performance porous coating for PDRC applications.

Keywords: metamaterials; optical simulation; porous polymer; radiative cooling.