DRIFT MOBILITY OF ELECTRONS IN INDIUM ANTIMONIDE IN THE WEAK ELECTRIC FIELD REGIME

In scientific publications, theoretical and experimental studies of the Hall mobility of indium antimonide are presented; its dependence on temperature, charge carrier concentration, and electric field strength. Note that a typical form of the weak-field temperature dependence of the electron drift mobility, showing its behavior in a wide range of temperature and impurity atom concentration, is not presented. The processes of charge carrier scattering in indium antimonide are poorly represented. The aim of this work is a detailed study of the main mechanisms of electron scattering in indium antimonide, the temperature dependence of the weak-field electron mobility in a wide range of the semiconductor doping degree. A quantitative assessment of the electron scattering rates in indium antimonide is given for the main types of impurity and phonon mechanisms. A detailed analysis of the scattering processes is carried out. It is emphasized that a difference in the scattering rates in the Г- and L-valleys of the conduction band is observed. Scattering by ionized impurity atoms determines the resulting scattering velocity up to 40 K. At temperatures above 40 K, the role of polar optical scattering in the Г-valley increases significantly, practically determining the behavior of the resulting velocity. In the L-valleys, the greatest contribution is made by 2 types of phonon scattering: acoustic and polar optical. Based on the obtained scattering process modeling results, the temperature dependence of the weak-field drift mobility in the Г- and L-valleys was calculated. From the simulation results it is clear that the mobility of electrons in the Г-valley exceeds the corresponding values in the L-valleys by 2 – 4 orders of magnitude. The resulting mobility is determined taking into account the valley population. From the results of modeling the drift mobility it is clear that the area of its increase is determined by the processes of scattering by impurity ions. The higher the doping degree of the semiconductor, the lower the electron mobility. With a further increase in temperature, the mobility decreases. A characteristic feature of the typical temperature dependence of the weak-field electron mobility in InSb is that at high temperatures its behavior is determined by scattering processes on polar optical phonons. A set of modeling parameters has been determined that ensure compliance with experimental data.