Lin Yen-Fu, Jian Wen-Bin
Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan.
Nano Lett. 2008 Oct;8(10):3146-50. doi: 10.1021/nl801347x. Epub 2008 Aug 27.
Nanowire-based nanoelectronic devices will be innovative electronic building blocks from bottom up. The reduced nanocontact area of nanowire devices magnifies the contribution of contact electrical properties. Although a lot of two-contact-based ZnO nanoelectronics have been demonstrated, the electrical properties bringing either from the nanocontacts or from the nanowires have not been considered yet. High quality ZnO nanowires with a small deviation and an average diameter of 38 nm were synthesized to fabricate more than thirty nanowire devices. According to temperature behaviors of current-voltage curves and resistances, the devices could be grouped into three types. Type I devices expose thermally activated transport in ZnO nanowires and they could be considered as two Ohmic nanocontacts of the Ti electrode contacting directly on the nanowire. For those nanowire devices having a high resistance at room temperatures, they can be fitted accurately with the thermionic-emission theory and classified into type II and III devices according to their rectifying and symmetrical current-voltage behaviors. The type II device has only one deteriorated nanocontact and the other one Ohmic contact on single ZnO nanowire. An insulating oxide layer with thickness less than 20 nm should be introduced to describe electron hopping in the nanocontacts, so as to signalize one- and high-dimensional hopping conduction in type II and III devices.
基于纳米线的纳米电子器件将自下而上成为创新的电子构建模块。纳米线器件减小的纳米接触面积放大了接触电学性质的贡献。尽管已经展示了许多基于双接触的氧化锌纳米电子器件，但尚未考虑来自纳米接触或纳米线的电学性质。合成了具有小偏差且平均直径为38纳米的高质量氧化锌纳米线，以制造三十多个纳米线器件。根据电流-电压曲线和电阻的温度行为，这些器件可分为三种类型。I型器件在氧化锌纳米线中表现出热激活传输，它们可被视为钛电极直接接触纳米线的两个欧姆纳米接触。对于那些在室温下具有高电阻的纳米线器件，它们可以用热电子发射理论精确拟合，并根据其整流和对称的电流-电压行为分为II型和III型器件。II型器件在单根氧化锌纳米线上只有一个劣化的纳米接触和另一个欧姆接触。应引入厚度小于20纳米的绝缘氧化层来描述纳米接触中的电子跳跃，以便表明II型和III型器件中的一维和高维跳跃传导。
