Electric Conduction of TiO2 Nanotube Field Effect Transistor Fabricated by Dielectrophoresis
Masayuki ISHII, Masahiro TERAUCHI, Takeshi YOSHIMURA, Tadachika NAKAYAMA and Norifumi FUJIMURA
Abstract:TiO2 nanotubes (TNTs) have attracted much attention as a material for photocatalysts, dye-sentisized solar cells and chemical sensors due to the chemical stability and large surface-to-bulk ratio. TNTs fabricated by a hydrothermal method have larger surface-to-bulk ratio than TNTs fabricated by other processes. To investigate the electrical properties of the hydrothermal TNTs, TNT field effect transistors were fabricated by dielectrophoresis. The temperature dependence of the drain current-drain voltage characteristics indicates that the electric conduction of the TNT-channel is dominated by double Schottky barrier (DSB) existing between the TNTs. In the result of the gate voltage dependence of the drain current-drain voltage characteristics, it was found that the carrier of the TNTs is electron and the modulation of the drain current is caused by the change of the carrier density in the TNTs rather than the change of the height of DSB. Key Words:TiO2, Nanotube, Field effect transistor, Dielectrophoresis, Double schottky barrier