Kang Qianlong, Li Dekui, Guo Kai, Gao Jun, Guo Zhongyi
School of Computer and Information, Hefei University of Technology, Hefei 230009, China.
Nanomaterials (Basel). 2021 Jan 20;11(2):260. doi: 10.3390/nano11020260.
Thermal radiation control has attracted increasing attention in a wide range of field, including infrared detection, radiative cooling, thermal management, and thermal camouflage. Previously reported thermal emitters for thermal camouflage presented disadvantages of lacking either tunability or thermal stability. In this paper, we propose a tunable thermal emitter consisting of metal-insulator-metal (MIM) plasmonic metamaterial based on phase-change material GeSbTe (GST) to realize tunable control of thermal radiation in wavelength ranges from 3 μm to 14 μm. Meanwhile, the proposed thermal emitter possesses near unity emissivity at the wavelength of 6.3 μm to increase radiation heat dissipation, maintaining the thermal stability of the system. The underlying mechanism relies on fundamental magnetic resonance and the interaction between the high-order magnetic resonance and anti-reflection resonance. When the environmental background is blackbody, the tunable emitter maintains signal reduction rates greater than 80% in middle-IR and longer-IR regions from 450 K to 800 K and from room temperature to 800 K, respectively. The dependences of thermal camouflage on crystallization fraction of GST, incident angles and polarization angles have been investigated in detail. In addition, the thermal emitter can continuously realize thermal camouflage for various background temperatures and environmental background in atmospheric window in the range of 3-5 μm.
热辐射控制在包括红外探测、辐射冷却、热管理和热伪装等广泛领域中受到了越来越多的关注。先前报道的用于热伪装的热发射体存在缺乏可调谐性或热稳定性的缺点。在本文中,我们提出了一种基于相变材料GeSbTe(GST)的金属-绝缘体-金属(MIM)等离子体超材料构成的可调谐热发射体,以实现3μm至14μm波长范围内热辐射的可调谐控制。同时,所提出的热发射体在6.3μm波长处具有接近单位的发射率,以增加辐射散热,保持系统的热稳定性。其潜在机制依赖于基本磁共振以及高阶磁共振与抗反射共振之间的相互作用。当环境背景为黑体时,可调谐发射体在中红外和长红外区域分别从450K到800K以及从室温到800K保持大于80%的信号降低率。详细研究了热伪装对GST结晶分数、入射角和偏振角的依赖性。此外,该热发射体可以在3-5μm范围内的大气窗口中针对各种背景温度和环境背景连续实现热伪装。