Master equation approach of classical noise in intersubband detectors

Abstract

Electronic transport in intersubband detectors is investigated theoretically and experimentally. Within the framework of inter--Wannier-Stark levels electron scattering, consistent dark current and low-frequency noise expressions are obtained through the resolution of the two first moments of a master equation for classical particles. In particular, the formulation of noise bridges over the vision of uncorrelated Johnson and shot contributions. Theoretical predictions are compared to measurements for five quantum well detectors, either photovoltaic or photoconductive, whose detection wavelength span from $8\phantom{\rule{0.222222em}{0ex}}\ensuremath{\mu}\text{m}$ to $17\phantom{\rule{0.222222em}{0ex}}\ensuremath{\mu}\text{m}$. Quantitative agreement with experiment is found for a broad range of biases and temperatures. Correlation effects are discussed and proven to either reduce or enhance the noise.