Numerical simulation of noise and detectivity of Infrared sensor for high performance thermal image processing applications

Infrared (IR) sensors are intensively used in the thermal image processing applications. IR sensors have dominant effects on the performance enhancement of a thermal imaging system. If performance characteristics of IR sensors are known prior to the costly and time-consuming production phase, high performance IR sensors could be obtained rapidly and cost effectively. In this study, performance characteristics of noise and specific detectivity of HgCdTe IR sensor are evaluated at 77 K sensor operating temperature using a numerical simulation method. These characteristics can not be determined with analytical methods. Results of the study showed that the best detectivity was obtained when cut-off wavelength is 9 μm and the bias voltage is -10 mV. It is also clarified that the degradation of the detectivity is caused by the 1/f noise originating from the trap-assisted tunneling (TAT).