High temperature mobility of CdTe

The Hall mobility of electrons μH is measured in CdTe in the temperature interval 450–1050 °C and defined Cd overpressure in near-intrinsic conditions. The strong decrease of μH above 600 °C is reported. The effect is explained within a model of multivalley conduction where both electrons in Γ1c minimum and in L1c minima participate. The theoretical description is based on the solution of the Boltzmann transport equation within the relaxation time approximation including the polar and acoustic phonon intravalley and intervalley scatterings. The Γ1c to L1c separation ΔE=0.29−10−4T (eV) for the effective mass in the L valley mL=0.35m0 is found to best fit the experimental data. Such ΔE is about four times smaller than it is predicted by first-principle calculations.