Two-step optical annealing effects on spin-coated InAl-doped ZnO thin films

Abstract

Different types of optical annealing methods were employed to enhance the crystallinity, increase the grain size, and reduce the residual stress of spin-coated InAl-doped ZnO thin films for transparent conducting oxide applications. A CO2 laser and a near-infrared (NIR) with wavelengths of 10,640 nm and 750-1400 nm, respectively, were employed for the optical annealing. Optical annealing using different wavelengths can be useful owing to the different penetration depths. The crystal structure and electrical and optical properties of the InAl-doped ZnO films were analyzed with X-ray diffraction analysis, a four-point probe, and a UV-vis spectrophotometer. The films showed a hexagonal wurtzite structure with a preferential c-axis orientation. In this experiment, we found that a two-step optical annealing process is effective for the curing of transparent conductive oxides. (C) 2014 Elsevier B.V. All rights reserved.