Numerical analysis of fluctuation phenomena in HOT HgCdTe barrier detectors

The effect of different noise sources on the noise current in HgCdTe barrier detectors, working at near-room temperatures, was analyzed theoretically. The set of transport equations for fluctuations was solved to obtain spectral densities of fluctuations of electrical potential, quasi-Fermi levels, and temperature. The spectral density of both, shot and lf fluctuations of generation-recombination processes were taken into account in the model to analyze their effect on noise currents. Effect of dislocations, metal site vacancies, as well as 1/f mobility fluctuations, thermal and diffusion noises have been included in the model. The built-in electric field regions have been identified as sources of shot GR noise and 1/f mobility noises. The barrier area is the main source of 1/f current noise in HgCdTe barrier detectors. The presence of misfit dislocations in the depletion regions results in the growth of dark current and hence the growth of noise current which is always proportional to the total dark current.