State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, 310027, Hangzhou, China.
Nanoscale. 2018 Mar 1;10(9):4415-4420. doi: 10.1039/c7nr09672k.
The ability to continuously tune the emission wavelength of mid-infrared thermal emitters while maintaining high peak emissivity remains a challenge. By incorporating the nonvolatile phase changing material GeSbTe (GST), two different kinds of wavelength-tunable mid-infrared thermal emitters based on simple layered structures (GST-Al bilayer and Cr-GST-Au trilayer) are demonstrated. Aiming at high peak emissivity at a tunable wavelength, an Al film and an ultrathin (∼5 nm) top Cr film are adopted for these two structures, respectively. The gradual phase transition of GST provides a tunable peak wavelength between 7 μm and 13 μm while high peak emissivity (>0.75 and >0.63 for the GST-Al and Cr-GST-Au emitters, respectively) is maintained. This study shows the capability of controlling the thermal emission wavelength, the application of which may be extended to gas sensors, infrared imaging, solar thermophotovoltaics, and radiative coolers.
能够在保持高峰值发射率的同时，连续调节中红外热发射器的发射波长仍然是一个挑战。通过引入非易失相变材料 GeSbTe（GST），展示了两种基于简单层状结构的波长可调中红外热发射器（GST-Al 双层和 Cr-GST-Au 三层）。针对可调波长下的高峰值发射率，这两种结构分别采用了 Al 膜和超薄（约 5nm）的顶层 Cr 膜。GST 的逐渐相变为 7μm 至 13μm 之间的可调谐峰值波长提供了条件，同时保持了高峰值发射率（GST-Al 和 Cr-GST-Au 发射器的发射率分别大于 0.75 和 0.63）。本研究展示了控制热辐射波长的能力，其应用可能扩展到气体传感器、红外成像、太阳能热光伏和辐射冷却器。
