Fu Yuting, Chen Le, Guo Yuao, Shi Yuqing, Liu Yanjun, Zeng Yuqiang, Lin Yuanjing, Luo Dan
Department of Electrical & Electronic Engineering, Southern University of Science and Technology, Xueyuan Road 1088, Nanshan District, Shenzhen, 518055, China.
School of Microelectronics, Southern University of Science and Technology, Shenzhen, 518055, China.
Adv Sci (Weinh). 2024 Oct;11(39):e2404900. doi: 10.1002/advs.202404900. Epub 2024 Aug 19.
Sub-ambient cooling technologies relying on passive radiation have garnered escalating research attention owing to the challenges posed by global warming and substantial energy consumption inherent in active cooling systems. However, achieving highly efficient radiative cooling devices capable of effective heat dissipation remains a challenge. Herein, by synergic optimization of the micro-pyramid surface structures and 2D hexagonal boron nitride nanoplates (h-BNNs) scattering fillers, pyramid textured photonic films with remarkable solar reflectivity of 98.5% and a mid-infrared (MIR) emittance of 97.2% are presented. The h-BNNs scattering filler with high thermal conductivity contributed to the enhanced through-plane thermal conductivity up to 0.496 W m K and the in-plane thermal conductivity of 3.175 W m K. The photonic films exhibit an optimized effective radiative cooling power of 201.2 W m at 40 °C under a solar irradiance of 900 W m and a daily sub-ambient cooling effect up to 11 °C. Even with simultaneous internal heat generation by a 10 W ceramic heater and external solar irradiance of 500 W m, a sub-ambient cooling of 5 °C can be realized. The synergic matching strategy of high thermal conductivity scattering fillers and microstructured photonic surfaces holds promise for scalable sub-ambient radiative cooling technologies.
由于全球变暖带来的挑战以及主动冷却系统固有的大量能源消耗，依靠被动辐射的亚环境冷却技术已获得越来越多的研究关注。然而，实现能够有效散热的高效辐射冷却装置仍然是一项挑战。在此，通过对微金字塔表面结构和二维六方氮化硼纳米片（h-BNNs）散射填料进行协同优化，制备出了具有98.5%的显著太阳反射率和97.2%的中红外（MIR）发射率的金字塔纹理光子薄膜。具有高导热率的h-BNNs散射填料使面内热导率提高到0.496 W m K，面内导热率达到3.175 W m K。该光子薄膜在900 W m的太阳辐照度下，40°C时表现出201.2 W m的优化有效辐射冷却功率，每日亚环境冷却效果高达11°C。即使在10 W陶瓷加热器同时产生内部热量和500 W m的外部太阳辐照度下，也能实现5°C的亚环境冷却。高导热率散射填料与微结构光子表面的协同匹配策略为可扩展的亚环境辐射冷却技术带来了希望。
