Influence of a plasma focus device on the structural and optical properties of highly conductive AZO thin films

Abstract

In the present work, we deposited Al-doped ZnO (AZO) thin films on microscope glass slides at different pressures (5, 10, 20, and 30 mTorr) using an EAEA-PFD (Plasma Focus Device of the Egyptian Atomic Energy Authority) without any extra heat treatment. Argon gas provided the radiant energy needed to form a crystalline AZO film. This study investigated the deposition and features of AZO thin films. The impact of changes in work pressure on the microstructure, morphology, and optical attributes of AZO films was reported. The results demonstrated that varying the work pressure significantly affects the microstructure, morphology, crystallinity, optical absorbance, and optical energy gap. The microstructure and morphology were evaluated through XRD and scanning electron microscopy (SEM). The optical properties were analyzed using a UVvis double-beam spectrophotometer within a wavelength range from 300 to 1100 nm. XRD patterns indicating a zinc-blende structure and the Williamson–Hall approach were used to estimate the structural parameters. The estimated trend in the particle size of the AZO film demonstrates a decrease from 82 ± 5 nm to 48 ± 5 nm as the pressure increases. The calculated energy gap, Egopt, increases from 3.53 eV to 3.69 eV with increasing work pressure. The conductivities in terms of both optical and electrical decreased with increasing work pressure of the AZO films.