Abstract
Transparent conductive oxides (TCO),such as SnO2, In2O3, CdO, and ZnO, have become increasingly important in a large variety of applications due to demands for optically-transparent, conductive materials.[1-2] To enhance the conductivity, we usually dope suitable atoms introduce more free carriers.[3] It has been widely used as electric leads in optoelectronic devices such as flat panel displays and thin film solar energy cells. A common TCO used in research and industry is tin-doped indium oxide (ITO). However, ITO experiences a reduction of electrical conductivity when exposed to oxygen at elevated temperatures (> 300 ℃). Therefore, FTO, which is much more thermally stable, is often used as an alternative to ITO. As device size continues to decrease, the potential use of nanoscaled structures of these TCOs grows. However, very little to no work has been published regarding the fabrication of FTO nanowires.[4] The authors report the growth of F-doped SnO2 single crystalline nanowires by carrying out the thermal evaporation of solid Sn and SnF2 powders a in an Ar/O2 ambient gas. We analyzed the samples with scanning electron microscopy, X-ray diffraction, transmission electron microscopy. From the EDS spectra, we can quantify fluorine-doping in the nanowires is about 2 at%. The electrical properties of rutile-type F-doped SnO2 low-dimensional structures were analysed using a scanning tunnelling microscopy (STM) in situ holder for transmission electron microscopes (TEM).The measured I-V curve obtained typically show Ohmic-like behavior between the gold electrode and F-doped SnO2 nanowires. And the resistivity of FTO NWs is 0.0278Ω-cm, much smaller than pure SnO2 NWs(289 Ω-cm).