Crystalline TIT TiO2 Nanotubes for High-Performance Field Emitters and Metal/Semiconductor/Metal Back-to-Back Schottky Diode

Crystalline TIT TiO2 nanotube arrays were successfully fabricated using a one-step anodic oxidation method. Their structural, electric and field emission (FE) properties have been systematically investigated, and the single-TIT nanotube device was assembled. The I-V characteristic results show that the observed rectifying behavior of the TIT nanostructure is analogous to the I-V characteristics of an n-type semiconductor/metal Schottky barrier diode. The temperature dependence of I-V characteristic for the Ag/TIT/Ti sandwich structures was explored for the TIT nanostructures. With the temperature increasing from 300 to 400 K, more free carriers are thermally generated and the conductivity of the TIT nanostrucutures increases by a factor of 15, showing typical semiconductor I-V characteristics. For the FE properties, the results clearly indicate that N-doped TIT nanostructure has greater field emission properties exhibiting from the higher field enhancement factor than that of the undoped one.