低温下单根ZnO纳米带电学性质的研究

Electrical properties of single ZnO nanobelt in low temperature

用化学气相沉积法在硅衬底上合成了宽1μm左右、长数十微米的ZnO纳米带.采用微栅模板法得到单根ZnO纳米带半导体器件,由I-V特性曲线测得室温下ZnO纳米带电阻约3 M,电阻率约0.4·cm.研究了在20—280 K温度范围内单根ZnO纳米带电阻随温度的变化.结果表明:在不同温度区间内电阻随温度变化趋势明显不同,存在两种不同的输运机制.在130—280 K较高的温度范围内,单根ZnO纳米带电子输运机制符合热激活输运机制,随着温度继续降低(<130 K),近邻跳跃传导为主导输运机制.

ZnO nanobelts are synthesized using chemical vapors deposition method on silica substrate. The average width of the nanobelts is H1 Um and the length is dozens of micron. Single ZnO nanobelt device is assembled using the micro-grid template method. The current-voltage characteristics are linear and the resistance and resistivity of the ZnO nanobelt are calculated to be ,~3 M~ and ,--~0.4 O.cm at room temperature, respectively. It is found that there are two different conduction mechanisms through the single ZnO nanobelt, according to the temperature dependence of the resistance of the single ZnO nanobelt at 20--280 K. In the higher temperature range （130-280 K） the thermally activated conduction is dominant. However, as the temperature comes down （〈 130 K）, the nearest- neighbor hopping conduction mechanism instead of the thermally activated conduction turns into the dominant conduction mechanism through the single ZnO nanobelt.