Study of topological morphology and optical properties of SnO₂ thin films deposited by RF sputtering technique

Transparent conducting thin films of tin dioxide (SnO₂) were prepared on glass substrates by RF sputtering technique. The as-deposited films were annealed at different temperatures (473, 673 and 823 K) for 3 h in air under normal atmospheric pressure. The film structure was characterized using atomic force microscopy (AFM). The optical properties of the prepared and annealed films were studied using their reflectance and transmittance spectra. The Urbach energy was found to decrease with increasing annealing temperature. The estimated direct optical band gap (E_g^d) values were found to decrease by annealing temperature. The photoluminescence (PL) spectroscopy measurement of the SnO₂ film shows that the band to band emission peak atE_g^PL=4.18 eV. The dispersion curves of the refractive index of SnO₂ thin films were found to obey the single oscillator model. - Highlights: • The structural and optical properties of RF Sputtered SnO₂ thin Films have been studied. • AFM has been used to identify the structure properties. • From fundamental absorption edge, a picture of the energetic transitions of was described. • Optical band gap were also obtained from optical PL measurements. • A single-oscillator model and Drude model were used to describe the refractive index