Influence of Working Pressure on Structural and Optoelectronic Properties of Al-Doped ZnO Thin Films

Abstract

In this study, we investigated the electrical, optical and structural properties of aluminum-doped ZnO (AZO) thin films by RF magnetron sputtering under different working pressure of 5 -40 mTorr. Optimization of the prepared thin films shows low resistivity of 6.11 × 10 -4 ȍ-cm, mobility of 4.295 cm 2 /V-s and carrier concentration of 3.277 × 10 20 cm -3 at working pressure of 5 mTorr. The maximum transmittance of 98.99 % for wavelengths above 600 nm and Haacke figure of merit (FOM) are 6.44 × 10 -3 ȍ -1 with working pressure of 5 mTorr. These results indicate that AZO thin films are a promising high conductivity transparent electrode scheme for solar cells and various displays applications.

Pressure Dependence of AZO Film Deposited by RF Powered Magnetron Sputtering System

“…The value of energy band gap Eg evaluated from the extrapolating linear part of the curve obtain from the graph ℎ 2 versus Photon energy ( ) where the estimated value of band gap value for AZO films is within 3.30 -3.50 range complement the XRD result that only doped ZnO phases that have been successfully deposited onto substrate . The band gap of AZO at lower pressure is broader than higher pressure indicated that as the pressure decreases the AZO films generates a blue shift as the carrier concentration increase [14]. The resistivity values for AZO films by the function of argon pressure are shows in fig 5 . As the argon pressure increase, the resistivity of AZO films also increase implied that the pressure influence the resistivity pattern of AZO films.…”