Optical and electrical properties of aluminum doped zinc oxide thin films at various doping concentrations

Abstract

Aluminum (Al) doped zinc oxide (ZnO) thin films have been prepared using sol-gel spin-coating method at various doping concentrations. The thin films were characterized using UV-Vis-NIR spectrophotometer and current-voltage (I-V) measurement system for optical and electrical properties respectively. The results show all films exhibit low absorbance in visible and near infrared (NIR) region. The calculated Urbach energy indicated the defects in the thin films increase with doping concentrations. The electrical properties of Al doped ZnO thin films improved with Al doping as measured through I-V measurement system.