Interaction between the excitons and electrons in ZnSe1-xSx epilayer under high excitation

Excitonic properties of ZnSe 1-x S x epilayer fabricated on GaAs substrate by a Ap-MOCVD have been investigated. Luminescence, excitation, and time-resolved spectroscopy have been employed to study the interaction between excitons and electrons at 77 and 300 K. Under pulsed N 2 laser excitation it is found that the peak shift of the near band edge emission is large, especially at room temperature. This is because the bottoms of the conduction bands are filled at higher temperature and the carriers from the exciton-exciton scattering must occupy higher energy levels. Therefore a shift of the peak toward lower energy is expected.