Paths for the Non-radiative Recombination Occurring in CdS:CdO/Si Multi-Interface Nanoheterostructure Array

A CdS:CdO/Si multi-interface nanoheterostructure array (CdS:CdO/Si-NPA) is prepared by a chemical bath deposition method, and three emission bands are observed in the as-grown CdS:CdO film. By measuring its temperature-dependent photoluminescence (PL) spectrum, the variation trends of the peak energies and intensities with temperature for the three bands are obtained. Based on the theoretical analyses and fitting results, the non-radiative recombination processes corresponding to the PL quenching for the three emission bands are attributed to the thermally activated transition between heavy-hole and light-hole levels (at low temperature) and the thermal escape due to the scattering from longitudinal optical phonons (at high temperature), the transition from acceptor levels to surface states, and the transition related to surface defect states, respectively. The clarification of the non-radiative recombination processes in CdS:CdO/Si-NPA might provide useful information for promoting the performance of optoelectronic devices based on CdS/Si nanoheterostructures.