Enhanced Field Emission Performance of ZnO Nanorods by Two Alternative Approaches
Enhanced Field Emission Performance of ZnO Nanorods by Two Alternative Approaches
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DOI：
10.1021/jp073928n
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发表时间：
2007-08
影响因子：
3.7
通讯作者：
C. Ye;Y. Bando;X. Fang;G. Shen;D. Golberg
中科院分区：
文献类型：
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作者：
C. Ye;Y. Bando;X. Fang;G. Shen;D. Golberg
直径为~ 150 nm的标准ZnO纳米棒表现出较差的场发射性能。为了显著改善场发射特性，我们开发了两种替代方法：第一种方法是将纳米棒的尖端半径减小到~ 5nm。第二种方法是用小金属颗粒装饰纳米棒。通过这两种方法中的任何一种，我们都可以获得优异的场发射性能，通常可以实现小至2 V/μm的导通场（电流密度达到10 μA/cm2的电场）和大至1 mA/cm2的电流密度。优异性能的物理本质是纳米棒尖端附近的局部场几何增强和纳米粒子的电子捐赠降低了ZnO纳米棒的功函数。
Standard ZnO nanorods with a diameter of ∼150 nm show poor field emission performance. In an attempt to dramatically improve the field emission properties, we developed two alternative methods: The first one is to decrease the tip radius of nanorods down to ∼5 nm. The second one is to decorate the nanorods by small metal particles. By either of these two approaches, we can obtain excellent field emission performances, typically turn-on field (the electric field at which the current density reaches 10 μA/cm2) as small as 2 V/μm and current density as large as 1 mA/cm2 can be readily achieved. The physical essence of the excellent performances is the geometrically enhanced local field near the tip of the nanorods and the lowered work function of ZnO nanorods by the donation of electrons from the nanoparticles.