Department of Materials Science and Engineering, National Tsing Hua University, Hsin-Chu, Taiwan 300, Republic of China.
Small. 2014 Jan 15;10(1):179-85. doi: 10.1002/smll.201301293. Epub 2013 Jul 29.
Enhanced electron field emission (EFE) behavior of a core-shell heterostructure, where ZnO nanorods (ZNRs) form the core and ultrananocrystalline diamond needles (UNCDNs) form the shell, is reported. EFE properties of ZNR-UNCDN core-shell heterostructures show a high emission current density of 5.5 mA cm(-2) at an applied field of 4.25 V μm(-1) , and a low turn-on field of 2.08 V μm(-1) compared to the 1.67 mA cm(-2) emission current density (at an applied field of 28.7 V μm(-1) ) and 16.6 V μm(-1) turn-on field for bare ZNRs. Such an enhancement in the field emission originates from the unique materials combination, resulting in good electron transport from ZNRs to UNCDNs and efficient field emission of electrons from the UNCDNs. The potential application of these materials is demonstrated by the plasma illumination measurements that lowering the threshold voltage by 160 V confirms the role of ZNR-UNCDN core-shell heterostructures in the enhancement of electron emission.
报道了一种核壳结构的增强电子场发射（EFE）行为，其中氧化锌纳米棒（ZNRs）作为核，超纳米金刚石针（UNCDNs）作为壳。ZNR-UNCDN 核壳结构的 EFE 特性在 4.25 V μm(-1) 的外加电场下表现出 5.5 mA cm(-2)的高发射电流密度，而开启场仅为 2.08 V μm(-1)，相比之下，裸 ZNRs 的发射电流密度为 1.67 mA cm(-2)（外加电场为 28.7 V μm(-1)），开启场为 16.6 V μm(-1)。这种场发射的增强源于独特的材料组合，从而实现了 ZNRs 到 UNCDNs 的良好电子传输和 UNCDNs 中电子的有效场发射。通过等离子体照明测量证明了这些材料的潜在应用，降低阈值电压 160 V 证实了 ZNR-UNCDN 核壳结构在增强电子发射中的作用。
