Electrical characteristics of silicon-tin oxide heterojunctions prepared by chemical vapor deposition

Abstract

Silicon-tin oxide heterojunctions were prepared by chemical vapor deposition of undoped as well as antimony-doped tin oxide on n-type silicon at 300 °C. Diode current-voltage (ID-V) and reverse capacitance-voltage (C-V) characteristics were measured in the temperature range of 294–394 K. The C-V measurements were taken at a number of frequencies f. The experimental data on diode quality factor n and semilogarithmic plots of the zero-bias current density intercept J0D vs T−1, and also of J0D vs T, indicated that the dominant carrier transport mechanism could be recombination generation in the case of undoped tin oxide, and trap-assisted tunneling in the case of antimony-doped tin oxide. The reverse C−2(V, T, f) characteristics indicated high barrier heights for all devices, but the presence of a much larger density of traps in the case of antimony-doped SnO2/n-Si heterojunctions than in the case of undoped SnO2/n-Si devices.