The relationship between stress and photoluminescence of Cd0.96Zn0.04Te single crystal

Photoluminescence (PL) and high-resolution X-ray diffraction (HRXRD) experiments have been carried out on strained Cd0.96Zn0.04Te single crystals to reveal the correlation between luminescence spectrum and stress in CdZnTe wafers. The tensile stress introduced by quenching was measured by X-ray diffraction methods. The photoluminescence spectra were found to move to higher energies, and the intensity of neutral donor bound exciton (D0, X) peak of CdZnTe wafer was increased after quenching. The reasons for these variations are suggested to be determined by the change of the energy band gap Eg of the CdZnTe wafer and the increase of crystal defects. The in-plane biaxial stress of 1 GPa results in a shift of the excitonic PL spectrum of 7.05–12.03 meV. In particular, the tensile strain reduces the formation energy of TeCd antisite defects, which are the shallow donors located at 0.01 eV below the conduction band. Therefore, high density of TeCd antisite defects demonstrated by the higher (D0, X) emission are generated due to the high tensile strain in the quenched specimen.