FABRICATION AND CHARACTERIZATIONS OF ZnO AND ZnO:Mn NANOCRYSTALLINE THIN FILMS

摘要

This paper provides a brief summary of the structural and optical study of ZnO and ZnO:Mn materials fabricated from simple process: oxidation of ZnS and ZnS:Mn thin films grown by LP-MOCVD. Both structural analysis and optical characterization have confirmed the good quality ZnO material formation. XRD results suggest that the fabricated ZnO film is composed of ～30 nm ZnO nanocrystals with a hexagonal wurtzite structure. Raman spectra show a strong resonant multiphonon effect. In all cases, a UV emission is observed at ～ 380 nm. A green emission is also observed in the ZnO nanocrystalline film. On the other hand, it is demonstrated that the Mn doping in ZnS film can dramatically affect the luminescence properties of end products: nanocrystalline ZnO thin films. The photoluminescence spectra of the films with an optimized Mn doping concentration only showed the ultraviolet emission, while the green emission was fully quenched. It is argued that the presence of the Mn can effectively passivate the electron and hole trapping sites at the surface and interface of the ZnO nanocrystals.