The Study and Simulation of the Electron Transport Phenomena on Bulk Hg1-xCdx Te Based on an Ensemble Monte Carlo Method
Mercury cadmium telluride (HgCdTe) is the material system of choice to fabricate high performance photovoltaic and avalanche detectors over the entire infrared spectral region. Several groups have reported an exponential gain curve and extremely low multiplication noise in electron injected HgCdTe Avalanche Photo detectors (APDs) at temperatures in the range of 77 K to 260 K for a variety of cut off wavelengths in the MWIR and LWIR bands.
These exceptional characteristics of HgCdTe APDs are indicative of the exclusive impact ionization of the electrons and of dead-space effects that tend to introduce order in the random impact ionization process, i.e., a history dependent gain mechanism. The electron impact ionization process in HgCdTe becomes important at relatively small electric fields due to the high mobility of electrons and their low impact ionization threshold energy.