Hyogo Prefectural Institute of Industrial Research, 3-1-12, Yukihira-cho, Suma-ku, Kobe 654-0037, Japan
Abstract:
Highly conducting and transparent indium tin oxide (ITO) thin films were prepared on SiO2 glass and silicon substrates by pulsed laser ablation (PLA) from a 90 wt.% In2O3-10 wt.% SnO2 sintered ceramic target. The growths of ITO films under different oxygen pressures (PO2) ranging from 1×10?4–5×10?2 Torr at low substrate temperatures (Ts) between room temperature (RT) and 200°C were investigated. The opto-electrical properties of the films were found to be strongly dependent on the PO2 during the film deposition. Under a PO2 of 1×10?2 Torr, ITO films with low resistivity of 5.35×10?4 and 1.75×10?4 Ω cm were obtained at RT (25°C) and 200°C, respectively. The films exhibited high carrier density and reasonably high Hall mobility at the optimal PO2 region of 1×10?2 to 1.5×10?2 Torr. Optical transmittance in excess of 87% in the visible region of the solar spectrum was displayed by the films deposited at Po2≥1×10?2 Torr and it was significantly reduced as the PO2 decreases.