Interdiffusion in wide-bandgap Zn(Cd)S(Se) strained layer superlattices

The extent of interdiffusion in wide-bandgap II-VI superlattices of Zn-ZnSe, ZnSe-CdSe and ZnS-CdS grown at low temperature is assessed by measuring the photoluminescence spectra and X-ray diffraction profiles of samples annealed in the temperature range from 300 to 550 degrees C. It is shown that although Zn-ZnSe superlattices are stable against anion interdiffusion over the entire temperature range, the common-anion systems ZnSe-CdSe and ZnS-CdS show evidence of disordering at anneal temperatures greater than 400 and 450 degrees C respectively. These results confirm that the common-anion binary superlattices are stable against interdiffusion at low growth temperature.