UV light emitting transparent conducting tin-doped indium oxide (ITO) nanowires

Abstract

Multifunctional single crystalline tin-doped indium oxide (ITO) nanowires withtuned Sn doping levels are synthesized via a vapor transport method. The Snconcentration in the nanowires can reach 6.4 at.% at a synthesis temperature of840 °C, significantly exceeding the Sn solubility in ITO bulks grown at comparable temperatures,which we attribute to the unique feature of the vapor–liquid–solid growth. As a promisingtransparent conducting oxide nanomaterial, layers of these ITO nanowires exhibit a sheetresistance as low as and measurements on individual nanowires give a resistivity of2.4 × 10 − 4 Ω cm with an electrondensity up to 2.6 × 1020 cm − 3, while the optical transmittance in the visible regime can reach ∼ 80%. Under the ultraviolet excitation the ITO nanowire samples emit blue light, which can beascribed to transitions related to defect levels. Furthermore, a room temperature ultravioletlight emission is observed in these ITO nanowires for the first time, and the exciton-relatedradiative process is identified by using temperature-dependent photoluminescencemeasurements.