Characterization of the oxygen oonosorption effect on a single SnO2 nanowire by using conductive atomic force microscopy.

We have verified that SnO2 nano-wire has an n-type semiconductor property and it can be a p-type one when it is exposed to O2. We employed conductive AFM system to measure the I-V curve and resistance of single SnO2 nano-wire which had been synthesized on the Au thin film by a thermal process. To analyze a effect of O2 ionosorption into nano-wire, resistance was measured with various O2 concentration and we observed increment and maintenance of resistance which caused by O2 ionosorption. Also, the O2 ionosorption causes a type transfer of semiconductor and this phenomenon was verified by comparing the Schottky property of nano-wire before and after O2 exposure.