Carrier concentration and compensation ratio dependence of electron drift mobility in InAs1−xSbx

The electron mobility in InAs1−xSbx is calculated for an ionized impurity density between 5× 1014 cm−3 and 1 × 1017 cm−3 at 77 K. The various methods of calculating electron mobility are discussed and their respective merits and limitations summarized. In general, alloy scattering is the mobility limiting process at low carrier density (n ≤ 1015 cm−3) while ionized impurity scattering is important at higher carrier density. The effect of compensation (NA/ND) on low field drift mobility is also calculated for a range of carrier concentrations at x=0.1, 0.6, 0.9, and 1.0 compositions of particular technological significance. Compensation is found to degrade electron mobility quite significantly in all cases. The calculations at x=1.0 (InSb) are also found to be in good agreement with available experimental data.