Air-Pressure Tunable Depletion Width, Rectification Behavior, and Charge Conduction in Oxide Nanotubes

作者：Alivov Yahya^*; Funke Hans H; Singh Vivek; Nagpal Prashant

来源：ACS Applied Materials & Interfaces, 2015, 7(4): 2153-2159.

DOI：10.1021/am5076666

• metal-oxide nanotubes
• Schottky diode
• air-tunable rectification
• air-gating
• chemical diodes

Metal-oxide nanotubes provide large surface areas and functionalizable surfaces for a variety of optical and electronic applications. Here we report air-tunable rectifying behavior, depletion width modulation, and two-dimensional (2D) charge conduction in hollow titanium-dioxide nanotubes. The metal contact forms a Schottky-diode in the nanotubes, and the rectification factor (on/off ratio) can be varied by more than 3 orders of magnitude (1-2 x 10(3)) as the air pressure is increased from 2 mTorr to atmospheric pressure. This behavior is explained using a change in depletion width of these thin nanotubes by adsorption of water vapor on both surfaces of a hollow nanotube, and the resulting formation of a metal-insulator-semiconductor (MIS) junction, which controls the 2D charge conduction properties in thin oxide nanotubes.

• 出版日期2015-2-4