Spin-independent and spin-dependent re-excitation in CdZnTe studied by pump-probe spectroscopy

Highlights: • The electron trapping time and lifetime decrease with the increasing Zn composition in CdZnTe. • The depression in the linearly polarized pump-probe spectrum demonstrates the presence of a re-excitation process in Cd_0.86Zn_0.14Te. • The re-excitation process leads to an abnormal reversal in the circularly polarized pump-probe spectrum of Cd_0.86Zn_0.14Te. -- Abstract: Time-resolved pump-probe spectroscopy is used to study the re-excitation processes of spin-balanced and spin-polarized electrons trapped by the defect levels in Cd_0.86Zn_0.14Te. In CdTe, Cd_0.96Zn_0.04Te, and Cd_0.86Zn_0.14Te, the electron trapping time and lifetime decrease with the increasing defect density of states that depends on the Zn composition. The abnormal linearly and circularly polarized pump-probe spectroscopies, respectively, demonstrate the presence of spin-independent and spin-dependent re-excitation processes in Cd_0.86Zn_0.14Te which have high defect density of states.