Broadband Ultrathin Absorber and Sensing Application Based on Hybrid Materials in Infrared Region

A broadband and ultra-thin absorber in the infrared region is proposed. The structure is composed of three layers, and the most remarkable difference is that two hybrid materials (Sn and InSb) are used in the top layer. The numerical results show that a broadband perfect absorption from 85.2 to 114.3 THz can be achieved for either transverse electric or magnetic polarization waves due to the effect of using hybrid materials. Moreover, the power loss and surface current distribution in the absorber are investigated to explain the physical mechanism of high absorption. The metamaterial absorber is ultra-thin, having total thickness of 0.3 μm, i.e.,λ/10 with respect to the center frequency of the high absorption bands. The proposed hybrid materials which are used in the same layer provides a useful way to realize a broadband perfect absorber in the infrared region and it is important for a variety of applications, such as solar energy harvest, sensors, and integrated photodetectors .