1/f Noise in InAs/InAsSb Superlattice Photoconductors

Abstract

This article concerns the temperature dependence of low-frequency noise measured in the temperature range of 77–300 K in InAs/InAsSb superlattice photoconductors optimized for long-wavelength infrared (LWIR) and very long-wavelength infrared (VLWIR) spectral range. The differences in the T-dependence and the magnitude of 1/f noise, observed for LWIR and VLWIR photoconductors, are connected with different scattering mechanisms. Using the Hooge empirical model of 1/f noise and modeling of the total mobility, it is suggested that either the phonon-related or the defect-related mobility fluctuations can be responsible for the measured noise depending on the mechanism which determines the total mobility. In the VLWIR photoconductors, the defect-related 1/f noise prevails, while the phonon-related component dominates in the LWIR detector. The latter is best described by the Melkonyan et al. ’s mobility fluctuation model, which assumes the phonon scattering as the origin of 1/f noise. It roughly explains the T-dependence and predicts the value to within the one order of magnitude.