氧化锌纳米棒场发射性能研究

Field emission from ZnO nanorods

采用简单物理气相沉积法制备出取向和非取向的氧化锌纳米棒,他们的场致电子发射性能测量结果表明,ZnO纳米棒具有较好的场发射性能,但是高度取向的ZnO纳米棒阵列并不利于获得高的场致电子发射电流密度.这可能是由于高密度ZnO纳米棒之间具有较高的屏蔽效应,降低了ZnO纳米棒阵列的场放大因子,从而影响了其场发射性能.相反,非取向ZnO纳米棒由于相互之间的屏蔽效应比较弱,而且表面存在容易成为发射中心的微小突起,表现出较好的场发射效果.这些结果不仅有助于加深我们对准一维纳米材料场致电子发射性能的理解,也为未来场发射电子器件的实际应用提供了可靠的依据.

The field emission properties of the randomly oriented and the well-aligned ZnO nanorods synthesized by a thermal evaporation method were investigated in detail. It was found that the field emission of the well-aligned ZnO nanorods is seriously affected by the screening effect. While, compared with the ZnO arrays, the field emission measurements on the randomly oriented ZnO nanorods show a lower turn-on filed and a larger field enhancement factor, which are attributed to the weak screening effect and the surface perturbations. These features make the random ZnO nanorods as a competitive candidate for field emission flat panel display.