Influence of thickness and annealing on photoluminescence of nanostructured ZnSe/ZnS multilayer thin films prepared by electron beam evaporation

In this paper, nanostructured ZnSe/ZnS multilayer thin films were prepared on silicon substrates by electron beam evaporation technique. This heterostructure takes advantage of the properties of ZnSe and ZnS, with ZnSe and ZnS acting as light-emitting and passivation layers, respectively. To enhance the luminescence performance, the optimal thickness of ZnS and ZnSe films and the annealing conditions were investigated. Nanostructured films with 3.5 nm ZnSe and 15 nm ZnS annealed at 660 °C for 100 min in N2 were found to be the optimal conditions. In addition, crystal structures and surface morphologies of the films were characterized, which showed outstanding blue emission. The excellent blue emission achieved in the optimized films indicates that nanostructured ZnSe/ZnS multilayer films could be used as novel luminescence materials.