Effect of annealing treatment on optical and
electrical properties of ZnO films
electrical properties of ZnO films
(Department of Applied Physics, Chongqing University, Chongqing 400044, China)
Abstract: The ZnO-Al films were prepared by R.F. magnetron sputtering system using a Zn-Al target(with purity of 99.99%). The obtained films were characterized by X-ray diffraction, SEM and optical and electrical measurements. The experimental results show that the properties of ZnO films can be further improved by annealing treatment. The crystallinity of ZnO films becomes better, and the optical gap energy is decreased, but thermoelectric power is enhanced after heat treatment. The optical gap energy decreases from 3.75eV to 3.68eV when the annealing temperature increases from 25℃ to 400℃.This can be ascribed to the decrease of carrier concentration, resulting in Burstein shift.
Key words: ZnO films; annealing treatment; Seebeck effect; optical gap energy