Xu Ruijia, Lin Yu-Sheng
State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou 510275, China.
Nanomaterials (Basel). 2020 Jul 24;10(8):1442. doi: 10.3390/nano10081442.
We present an on-chip tunable infrared (IR) metamaterial emitter for gas sensing applications. The proposed emitter exhibits high electrical-thermal-optical efficiency, which can be realized by the integration of microelectromechanical system (MEMS) microheaters and IR metamaterials. According to the blackbody radiation law, high-efficiency IR radiation can be generated by driving a Direct Current (DC) bias voltage on a microheater. The MEMS microheater has a Peano-shaped microstructure, which exhibits great heating uniformity and high energy conversion efficiency. The implantation of a top metamaterial layer can narrow the bandwidth of the radiation spectrum from the microheater to perform wavelength-selective and narrow-band IR emission. A linear relationship between emission wavelengths and deformation ratios provides an effective approach to meet the requirement at different IR wavelengths by tailoring the suitable metamaterial pattern. The maximum radiated power of the proposed IR emitter is 85.0 µW. Furthermore, a tunable emission is achieved at a wavelength around 2.44 µm with a full-width at half-maximum of 0.38 µm, which is suitable for high-sensitivity gas sensing applications. This work provides a strategy for electro-thermal-optical devices to be used as sensors, emitters, and switches in the IR wavelength range.
我们展示了一种用于气体传感应用的片上可调谐红外（IR）超材料发射器。所提出的发射器具有高电热光效率，这可通过微机电系统（MEMS）微加热器与红外超材料的集成来实现。根据黑体辐射定律，在微加热器上施加直流（DC）偏置电压可产生高效红外辐射。该MEMS微加热器具有皮亚诺形状的微结构，展现出良好的加热均匀性和高能量转换效率。顶部超材料层的植入可使微加热器辐射光谱的带宽变窄，以实现波长选择性和窄带红外发射。发射波长与形变速率之间的线性关系为通过定制合适的超材料图案来满足不同红外波长的要求提供了一种有效方法。所提出的红外发射器的最大辐射功率为85.0微瓦。此外，在波长约2.44微米处实现了可调谐发射，半高宽为0.38微米，适用于高灵敏度气体传感应用。这项工作为电热光器件在红外波长范围内用作传感器、发射器和开关提供了一种策略。
