Microstructure, electrical and optoelectronic characterizations of transparent conductive nanocrystalline In2O3:Sn thin films

In this study Sn doped In 2 O 3 (ITO) thin films were deposited on glass substrates by e-beam evaporation technique at different oxygen partial pressure and then were annealed in vacuum at 400 ∘ C for 1 h. The effects of oxygen partial pressure on the crystallite size, dislocation density, outer cut-off radius of dislocation, fraction of edge and screw dislocation types, the electrical resistivity, optical transmittance, refractive index, porosity and optical band gap energy were studied. The films deposited at an optimized oxygen partial pressure of 1 × 10 - 4 mbar showed high transparency (88 %) over the visible wavelength region, low electrical resistivity of 3.2 × 10 - 4 Ω cm and the optical band gap of 3.63(3) eV. It is also observed that the best crystal quality (high crystallite size and low dislocation density) are obtained in partial pressure of 1 × 10 - 4 mbar, indicating the oxygen partial pressure is a key factor in controlling the microstructure, electrical and optical properties of ITO films.