Applied Surface Science, Vol.256, No.20, 6025-6028, 2010
On tuning the orientation of grains of spray pyrolysed ZnO thin films
Effect of varying spray rate on the structure and optoelectronic properties of spray pyrolysed ZnO film is analysed. ZnO films were characterised using different techniques such as X-ray diffraction (XRD), photoluminescence, electrical resistivity measurement, and optical absorption. The XRD analysis proved that, with the increase in spray rate, orientation of the grains changed from (1 0 1) plane to (0 0 2) plane. The films exhibited luminescence in two regions-one was the 'near band-edge' (NBE) (similar to 380 nm) emission and the other one was the 'blue-green emission' (similar to 503 nm). Intensity of the blue-green emission decreased after orientation of grains shifted to (0 0 2) plane. Scanning electron microscope (SEM) analysis of the films asserts that spray rate has major role in improving the crystallographic properties of the films. Moreover resistivity of the films could be lowered to 2.4 x 10(-2) Omega cm without any doping or post- deposition annealing. (C) 2010 Elsevier B.V. All rights reserved.