High performance logic devices based on single crystalline ZnO nanorods

A variety of elements and crystal structures of metal oxides allows for the integration of many magnetic, electronic, and optoelectronic functions into the materials, providing significant potential for realizing a diverse range of active devices [1]. For example, transparent conducting oxides (TCOs) such as indium-tin-oxide (ITO), SnO2, and ZnO have widely been used as window electrodes for flat panel displays, touch panels, and solar cells because of their unique features of excellent optical transparency and controllable electrical conductivity by impurity doping. Conventional TCOs have also been studied as semiconducting channel of thin-film transistors (TFTs) for invisible electronic circuit applications, but which are limited by the poor device performance resulting from the lack of high quality oxide semiconductor materials. The key parameters of SnO2 and ZnO TFTs, field-effect mobilities have been ranged from 0.1 to 10 cm2/Vs [2]. Since charge scattering by ionized impurities and grain-boundaries is thought to limit the performance, preparation of high-quality single-crystalline TCO with a low background carrier concentration is challengeable.