Improved photoluminescence properties of oxidized anodically etched porous Zn

The intent of this paper is to study the preparation of improved photoluminescence (PL) properties from zinc oxide (ZnO) using a combination of anodic etching of Zn and subsequent annealing at various temperatures. PL spectra measurements and scanning electron micrographs (SEM) are taken on these samples. It is found that ambient air annealing of porous Zn (p-Zn) at 380 °C yields efficient UV luminescence with a very weak deep-level defect-related luminescence. Low-temperature PL measurements on these ambient air annealed p-Zn reveal three excitonic emission peaks similar to high quality ZnO. The anodically etched p-Zn oxidizes four times faster than the reference polished Zn. These results strongly suggest that high quality ZnO can be formed by a simple ambient air annealing, due to enhanced oxidation from a larger surface area, which is created by an anodic etching of Zn.