Effect of Spin Rate on the Properties of Zn0.98Al0.02O Transparent Films

Abstract

Zn0.98Al0.02O thinfilms were deposited onto glass substrate through spin coating technique with different chuck rotation rates (rpm’s) and the effect of rpm on their structural, optical and photoluminescence properties were investigated. The structural results confirm the good adhesive nature of the films with glass substrate and formation of hexagonal wurtzite crystal phase with an average crystallite size of 20 nm. Small significant effect on the crystallinity was observed with increase in the chuck rotation speed (rpm), whereas the thickness of the films found to decreases. The optical absorbance and transmittance measurements were recorded in the wavelength range 250 - 1000 nm. Optical studies confirm the films with > 85% transparency in the visible wavelength region were achieved. Photoluminescence (PL) excitation spectra of films were recorded under the emission wavelength of 450 nm. It reveals the distinct peak at 329 nm and it also shows distinct emission peaks at 408, 450, 483 and 530 nm for excitation wavelength of 329 nm and these emission peaks are assigned to the defects induced by the Al3+ substitution.