Modeling and ATLAS simulation of Hg Cd Te based MWIR photo detector for free space optical communication

In this paper we report a theoretically simulated Hg_1-xCd_xTe based heterojunction medium wavelength infrared (MWIR) photodetector for operation at temperature 78 K. The detector is designed to operate at strategic atmospheric window in the MWIR (3.8 mum) region with a high value of detectivity (>10⁸ mHz^1/2W^-1) and quantum efficiency (~ 60%). The device has been modeled using closed form analytical formula and is also simulated using the device simulation software ATLAS from SILVACO^reg international. The device has been theoretically characterized using the above models in respect of energy band diagram, electric field profile, current voltage characteristics, spectral response, quantum efficiency and detectivity. The detector is expected to find application in free space optical communication at 3.8 mum.