The dependence of the polycrystalline structure and electroluminescent properties of ZnS:Mn deposited on Y 2O 3 films on thickness

Abstract

The dependence of polycrystalline structure and electroluminescent (EL) properties of ZnS:Mn on the thickness of ZnS:Mn thin films deposited on Y 2O 3 films at 200°C by electron-beam evaporation has been investigated. RHEED experiments showed that the Y 2O 3 film deposited on a transparent electrode at 200°C had a fiber structure with [100] orientation. It was found from RHEED observation that ZnS:Mn films with thickness below about 500Ådeposited over the Y 2O 3 film had a zincblende structure which changed to a fiber structure with [111] orientation as the film thickness increased. The brightness and the efficiency of ZnS:Mn thin film EL devices with a thickness below about 1000Åwere lower than those of EL devices with a thickness above 1000Å. These effects are attributed to a very poor crystallinity in the transition region from [100] to [111] orientation during the early stages of growth.