Micro-Structural, Surface Morphological, and Optical Properties of Sol–Gel Spin Coated Sb-Doped SnO2 Thin Films

Abstract

Antimony (Sb: 2 to 10 wt %) doped SnO₂ thin films were synthesized by sol–gel spin coating process. X-ray diffraction (XRD) analysis of Sb-doped SnO₂ films exhibits polycrystalline tetragonal structure with orientation along (1 1 0). The crystallite size of Sb-doped SnO₂ films decreased from 32 to 14 nm with increased Sb dopant in SnO₂. The micro-structural parameters micro-strain, dislocation density, stress, and strain energy density values are affected by Sb dopant in SnO₂. The morphology of the films shows spherical-shaped particles composed of an aggregation of small-size crystallites. The surface roughness parameters of Sb-doped SnO₂ thin films were analyzed using atomic force microscopy. X-ray photoelectron spectroscopy studies confirm the presence of Sn⁴⁺ and low-valence states of Sb³⁺. The optical band gap of Sb-doped SnO₂ thin films varied from 3.57 to 4.16 eV with an increment of the doping concentration of Sb in SnO₂.