Effect of annealing temperature on PL spectrum and surface morphology of zinc oxide thin films

Zinc oxide (ZnO) thin films were produced by thermal oxidation of Zn layers (200 nm thickness) which were coated on Si (1 0 0) substrate by DC magnetron sputtering. In order to study the effect of annealing temperature on photoluminescence (PL) properties and the surface morphology of the ZnO samples, the annealing temperature range of 500–700 °C was employed. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) for investigation of surface morphology of the ZnO samples were carried out. The surface statistical characteristics of these ZnO thin films are then evaluated against data which outcome from AFM. SEM and AFM results indicated that the annealing temperature produces larger grains and rough surfaces at higher temperatures. The results of PL spectra represent an increase in interstitial zinc with increasing annealing temperature.