The investigation of structural, surface topography, and optical behaviors of Al-doped ZnO thin films with annealing temperature deposited by RF magnetron sputtering

Aluminum-doped Zinc oxide (AZO) thin films were sputtered on glass substrates, by RF magnetron sputtering method. The prepared films are annealed in the electrical furnace at various temperatures such as room temperature, 350, and 450 degrees C. The influence of annealing temperature on the structural, surface topography, and optical properties was evaluated. The structural characteristics of AZO films were investigated by XRD and FESEM analyses. The optical values were determined by ultraviolet-visible spectroscopy. The band gap energy was measured by the DITM method without the need of film thickness and any presumption about transition natural. The type of optical transition, refractive index, and dielectric constant at the absorption edge and their relationship with band gap energy were calculated by this method. The other optical quantities including Urbach energy, the strength of electron-phonon interaction, the penetration depth, optical density, dissipation factor, lattice dielectric constant, and optical conductivity of the films were also reported. The surface topography of the samples was measured by AFM technique and its relationship was investigated with Urbach energy. The highest optical transmittance was observed in the visible range for films annealed at 350 degrees C which make them applicable for optoelectronic devices.

Automated summary

Aluminum-doped Zinc oxide (AZO) thin films were fabricated on glass substrates using RF magnetron sputtering. The films were then annealed at room temperature, 350 and 450 degrees C, and their structural, surface topography, and optical properties were investigated. XRD and FESEM analyses were used to study the structural characteristics of the AZO films. UV-visible spectroscopy was employed to determine the optical values. The DITM method was utilized to measure the band gap energy without the need for film thickness or assumptions about transition nature. The optical transition type, refractive index, and dielectric constant at the absorption edge, as well as their relationship with the band gap energy, were calculated using this method. Additionally, other optical quantities such as Urbach energy, electron-phonon interaction strength, penetration depth, optical density, dissipation factor, lattice dielectric constant, and optical conductivity were reported for the films. The surface topography of the samples was measured using AFM technique, and its relationship with Urbach energy was investigated. The films annealed at 350 degrees C exhibited the highest optical transmittance in the visible range, making them suitable for optoelectronic devices.