氧化锌纳米线的紫外光耦合增强场电子发射特性

摘要

本文采用热化学气相沉积方法制备氧化锌纳米线阵列，研究氧化锌纳米线阵列在紫外光辐照下的场电子发射特性．实验结果表明，在紫外光辐照下，氧化锌纳米线场发射开启电压降低，发射电流明显增大．机理分析认为，氧化锌纳米线紫外光增强的场发射源自场电子发射与半导体耦合作用，紫外光激发价带电子跃迁到导带和缺陷能级使发射电子数量增加，同时，光生电子发射降低了发射材料表面的有效功函数，从而显著增强场电子发射性能．氧化锌纳米线具有紫外光耦合增强场电子发射特性，在光传感、冷阴极平板显示和场发射电子源等方面具有潜在的应用价值．%In this paper, ZnO nanowire （NW） arrays are prepared by the thermal chemical vapor deposition （CVD） method, and the characteristic of field electron emission of ZnO NW arrays under the illumination of ultraviolet light is investigated. It is found that, upon ultraviolet light illumination, the turn-on voltage drops off and emission current increases. A process of field emission coupled with semiconducting properties of ZnO NWs is proposed. Ultraviolet photon-excited electron transition from valence band to conductance band and defect energy levels of ZnO NWs can lead the number of emitting electrons to increase, and the photoemission reduces the effective work function of zinc oxide emitters, which largely enhances the field emission performance. The characteristic of field emission of ZnO NWs under ultraviolet light illumination suggests an approach to tuning field emission of semiconductor emitters, which is promising for the applications in optical sensor, cold-cathode flat panel display and field electron source.