Investigation on the optical and electrical properties of undoped and Sb-doped SnO2 nanowires obtained by the VLS method

Abstract

In this work, we report the effects of Sb doping on the optical and electrical properties of the SnO2 nanowires obtained by the vapor-liquid-solid (VLS) method. The absorption edges were found to be 3.30 eV and 3.66 eV for undoped SnO2 and Sb-doped SnO2 (ATO) nanowires, respectively. The energy shift was related to the Burstein-Moss effect taking place in the doped nanowires. We studied the ATO optical bandgap (ΔE = 0.36 eV) shift as a function of carrier concentration. The incorporation of Sb caused the resistivity to decrease three orders of magnitude for single-nanowire ATO devices. In addition, it was found that undoped SnO2 nanowires exhibit semiconductor characteristics while a metal-insulator transition (MIT), around 170 K, was observed in the ATO nanowires.