A Solution-Processed Inorganic Emitter with High Spectral Selectivity for Efficient Subambient Radiative Cooling in Hot Humid Climates

作者：Lin, Chongjia; Li, Yang; Chi, Cheng; Kwon, Ye Seul; Huang, Jingyuan; Wu, Zuoxu; Zheng, Jiongzhi; Liu, Gongze; Tso, Chi Yan; Chao, Christopher Y. H.^*; Huang, Baoling^*

来源：Advanced Materials, 2022, 34(12): 2109350.

DOI：10.1002/adma.202109350

• cooling temperature
• hot humid climates
• inorganic emitters
• selective thermal emission
• subambient radiative cooling

Daytime radiative cooling provides an eco-friendly solution to space cooling with zero energy consumption. Despite significant advances, most state-of-the-art radiative coolers show broadband infrared emission with low spectral selectivity, which limits their cooling temperatures, especially in hot humid regions. Here, an all-inorganic narrowband emitter comprising a solution-derived SiOxNy layer sandwiched between a reflective substrate and a self-assembly monolayer of SiO2 microspheres is reported. It shows a high and diffusive solar reflectance (96.4%) and strong infrared-selective emittance (94.6%) with superior spectral selectivity (1.46). Remarkable subambient cooling of up to 5 degrees C in autumn and 2.5 degrees C in summer are achieved under high humidity without any solar shading or convection cover at noontime in a subtropical coastal city, Hong Kong. Owing to the all-inorganic hydrophobic structure, the emitter shows outstanding resistance to ultraviolet and water in long-term durability tests. The scalable-solution-based fabrication renders this stable high-performance emitter promising for large-scale deployment in various climates.

• 单位
  清华大学