Conduction band electron relaxation and spin relaxation dynamics in CdZnTe alloy

Conduction band electron relaxation and spin relaxation dynamics in Cd_0.96Zn_0.04Te alloy are investigated using time-resolved pump-probe spectroscopy. The measured linearly polarization pump-probe spectroscopy demonstrates the presence of a fast process and a slow process, both of which indicate electron trapping and recombination at the defect/impurity level. The time constants of the fast process are within the range of 3.1 to 4.9 ps, and those of the slow process are within the range of 16.1 to 18.1 ps. During the ultrafast thermalization process in the first picosecond, an oscillating signal that results from the band gap renormalization (BGR) effect is found. The D'yakonov-Perel' (DP) mechanism dominates the spin relaxation process, and the spin relaxation slows down with the incorporation of Zn, because of the decrease of spin-orbit splitting energy and enhancement of electron-impurity scattering.