Photoluminescence characteristics of ZnTe epilayers

High quality ZnTe epilayers have been grown on semi-insulating GaAs(100) su bstrates by hot-wall epitaxy, and the photoluminescence characteristics wer e investigated. The free exciton binding energy is found to be 12.7 meV and the free exciton reduced mass to be 0.095m(0) from the clearly resolved ex citonic peaks. From the temperature dependence of the free exciton line, th e room temperature energy gap of ZnTe epilayer is found to be 2.278 eV. The longitudinal optical phonon energy from the resonance Raman shift is deter mined as 26.2 meV. The binding energy of the exciton bound to the neutral a cceptor is found to be 4.9 meV. The temperature dependence of the bound exc iton peak intensity is explained with a two-step thermal quenching mechanis m. Deep level emissions such as donor-acceptor pair emission, Y-band, and o xygen-bound emission are also studied. (C) 2001 American Institute of Physi cs.