Study on aluminum concentration on optical and electrical properties of AZO thin films fabricated by ultrasonic spray pyrolysis

Abstract

In this work, transparent and conductive Al-doped ZnO (AZO) nanofilms were prepared on quartz substrate by ultrasonic spray pyrolysis (USP) method. The effects of Al/Zn atomic ratios on the micro-structural, morphological, optical photoluminescence and electrical properties of AZO thin films were effectively investigated. All the prepared samples showed hexagonal wurtzite structure. The scanning electron microscopy (SEM) showed that the surface morphology of all samples changed with the substrate temperature. The average transmittance of all AZO samples was higher than 85% in the visible region. The photoluminescence (PL) spectrum of the samples showed that the near band edge emission in PL spectra shifted to shorter wavelengths with increasing Al-doped concentration. The lowest sheet resistance was obtained for the samples prepared with 4% at. Al-doped value. The electrical conductivity of AZO films was improved by Al doping, which allowed their use as optoelectronic materials.