Effects of Oxygen Partial Pressure on the Electrical and Optical Properties of Pulsed-Laser-Deposited Sb-Doped SnO[sub 2] Films

Abstract

We have investigated the electrical and optical properties of pulsed-laser-deposited Sb-doped SnO2SnO2 films ( 250nm250nm thick) as a function of the oxygen partial pressure. The SnO2SnO2 films were grown on glass substrates using a SnO2SnO2 target containing 5atom%5atom% Sb. The distance between the substrate and the target was 7cm7cm and working pressure varied from 1.1to13.3Pa1.1to13.3Pa . The target was ablated using KrF excimer laser with energy density of 3.75J∕cm23.75J∕cm2 . It is shown that the electrical and optical properties of the films grown at 480°C480°C with 3000 pulses sensitively depend on the oxygen pressure. The electron concentration is maximum (5.6×1020cm−3(5.6×1020cm−3 ) at 4Pa4Pa , the electron mobility is maximum (8.5cm2V−1s−1)(8.5cm2V−1s−1) at 9.3Pa9.3Pa , and the resistivity is minimum (2.5×10−3Ωcm)(2.5×10−3Ωcm) at 4Pa4Pa . The transmittance is shown to depend on the oxygen pressures. X-ray diffraction results show that the crystalline quality of the films becomes improved with decreasing oxygen pressure. It is further shown that the sample grown at 1.1Pa1.1Pa contains oxygen-deficient phases. The UV absorption edge of the films shifts toward the shorter wavelengths with decreasing oxygen pressure, which is attributed to Burstein–Moss shift.