Enhanced material, structural, optical, and electrical characterization of fabricated aluminium-doped zinc oxide thin films deposited via aerosol-assisted-chemical-vapor-deposition (AACVD) using oxygen as a carrier gas

Studies have reported the use of nitrogen as a carrier gas in the synthesis of Aluminium-doped Zinc oxide (AZO) thin films using the Aerosol-assisted-chemical-vapor-deposition (AACVD) technique for material applications, but the use of oxygen as a carrier gas is scarcely reported. This study investigates the fabrication and structural analysis of AZO thin films deposited using the AACVD technique with oxygen as a carrier gas to aid the understanding of how oxygen carrier gas impacts the material characteristics of AZO thin films for diverse energy and material applications. The effects of varying aluminium doping concentrations on the structural, optical, electrical and surface properties of thin films were systematically explored. Characterization techniques using X-ray Diffraction, UV–visible Spectroscopy, Energy Dispersive X-ray Spectroscopy, Scanning Electron Microscopy, Atomic Force Microscopy, Profilometry, and Hall Effect measurements revealed improved optical, electrical, and surface properties, enhanced crystallinity, and reduced structural defects with oxygen as carrier gas at optimal aluminium doping levels. Increasing aluminium doping decreased crystallite size, while increasing dislocation density, attributable to lattice strain. Optical analysis showed a widening bandgap, from 3.57 eV (undoped-ZnO) to 3.59 eV at 5% aluminium doping, but decreased to 3.4 eV at 20% aluminium doping. The films exhibited high UV absorbance and broadened visible-spectrum absorption at higher doping levels, enhancing their applicability in optoelectronic devices. The findings highlight the role of oxygen in optimizing film properties, tailoring AACVD parameters for specific industrial applications, and underscore the potential of AZO films in advancing energy technologies.