Uncertainty in the estimation of the InAs1-xSbx intrinsic carrier concentration

In the last two decades an implementation of barrier detectors considerably strengthen the position of InAsSbbased bulk and superlattice structures in infrared detector family. In spite of fact that the dependence of InAs1-xSbx energy gap (Eg) on Sb, x-composition and temperature, T, has been experimentally investigated by many research groups since 1964, its Eg(x,T) dependence is not precisely evaluated. An uncertainty in Eg(x,T) value has detrimental influence on the intrinsic carrier concentration estimate. This paper attempts to critically assess the relevant literature data on this topic. The paper presents theoretical analysis of the bowing parameter influence on the energy gap and intrinsic carrier concentration versus the Sb molar composition and temperature. The calculations are carried out for temperature range 100-300 K. The obtained results differ significantly from ones used so far, especially in the low temperatures range having important implications on the InAsSb material properties and device performance. The proper correlation between theoretical predictions and experimental data has been reached only in the range of higher temperatures (above 200 K).