Hole. Transport in HgCdTe

摘要

While Mercury Cadmium Telluride (MCT) epilayers are important from a technological point of view, bulk crystals are ideally suited for studies of fundamental material properties such as mobility. Even though electronic transport has been treated well in the literature hole transport has not been studied much in MCT despite the popular device structure being n~+ on p. This may be due to the high electron mobility dominating low magnetic field transport even in p-type samples. In comparison of theoretical models with experimental data analyzed using multicarrier methods, relaxation time approximation has been used in some places which is not rigorously justified for polar optical phonon scattering. We use high pulsed magnetic fields to probe the low mobility holes in bulk p-type Hg_(0.79)Cd_(0.21) Te bulk crystals. Multicarrier analysis was used to extract hole mobilities from measured conductivity tensor at higher temperatures from 200K-300K in magnetic fields upto 15T. We have solved Boltzmann transport equation numerically without relaxation time approximation to include polar optical phonon scattering. Other scattering mechanisms taken into account are: ionized impurity, nonpolar optical, acoustic. Results are presented comparing our data with the calculated mobility.