High frequency response of LWIR HgCdTe photodiodes operated under zero-bias mode

Abstract

High frequency response is an important capability of infrared detectors in many applications. High-temperature long wavelength infrared HgCdTe heterostructure photodiodes exhibit sub-nanosecond time constants while operating under reverse bias. However, the noise, as well as the high current requirements are severe obstacles to their widespread applications. Thus, the present efforts are focused on a zero-bias operation of infrared detectors. A numerical modelling was used for investigation of the device design on the response time and current responsivity of HgCdTe photodiodes operating at 200 K and zero-bias mode. The program based on the solution of the system of the carrier transport equations including the whole spectrum of various generation and recombination mechanisms. To determine the response time of devices, the Fourier expansion method was applied.