Structural and Optical Characterization of $\text{Au}: \text{SnO}_{2}$ Thin Films Deposited via DC Sputtering and GLAD Techniques

Abstract

This study explores the impact of deposition angle on the structural and optical properties of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Au}: \text{SnO}_{2}$</tex> thin films prepared using a combination of DC sputtering and Glancing Angle Deposition (GLAD) techniques. Films were deposited at particle flux angles (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\alpha$</tex>) 0° (planar) and 80° (oblique). Optical transmittance shows that films deposited at an oblique angle <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\left(\alpha=80^{\circ}\right)$</tex> exhibit reduced transparency compared to those deposited at a planar angle <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\left(\alpha=0^{\circ}\right)$</tex>. This decrease in transmittance is attributed to the unique nanostructured morphology induced by GLAD, which can promote light scattering and localized surface plasmon resonance (LSPR) effects due to the incorporated gold, thereby enhancing light interaction and scattering, with absorption enhanced at LSPR peak. XRD analysis reveals the crystalline phases of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SnO}_{2}$</tex>, with the presence of gold peaks indicating the successful incorporation of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{A u}$</tex> within or alongside the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{S n O}_{2}$</tex> matrix. These findings highlight the significant influence of GLAD and Au doping on the film's characteristics, offering valuable insights for tailoring <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Au}: \text{SnO}_{2}$</tex> thin films for various optoelectronic, photovoltaic and biomedical applications.