Study on the Effect of Oxygen Defects on the Electrical and Optical Properties of Thin Films

SnO₂ thin films grown directly on the Si substrate had larger average grain sizes as the power intensity increased, but the average grain size of the SnO₂ thin films grown in oxygen atmosphere decreased as the power intensity increased. Hall measurement of pure SnO₂ thin films showed that the carrier density increased with increasing power. However, upon annealing the SnO₂ thin films, the carrier density decreased with increasing power owing to the formation of oxygen vacancies and the SiO₂ layer between the Si substrate and SnO₂ thin films. The photoluminescence (PL) of the SnO₂ thin film grown in the oxygen atmosphere changed, and it was affected by the oxygen defects at the surface and interfaces of the thin film.