Chang Ting-Hsun, Kunuku Srinivasu, Hong Ying-Jhan, Leou Keh-Chyang, Yew Tri-Rung, Tai Nyan-Hwa, Lin I-Nan
Department of Materials Science and Engineering, National Tsing-Hua University , Hsinchu 300, Taiwan R.O.C.
ACS Appl Mater Interfaces. 2014 Jul 23;6(14):11589-97. doi: 10.1021/am502330v. Epub 2014 Jul 3.
The enhanced lifetime stability for the carbon nanotubes (CNTs) by coating hybrid granular structured diamond (HiD) films on Au-decorated CNTs/Si using a two-step microwave plasma enhanced chemical vapor deposition process was reported. Electron field emission (EFE) properties of HiD/Au/CNTs emitters show a low turn-on field (E0) of 3.50 V/μm and a high emission current density (Je) of 0.64 mA/cm(2) at an applied field of 5.0 V/μm. There is no notable current degradation or fluctuation over a period of τ(HiD/Au/CNTs) = 360 min for HiD/CNTs EFE emitters tested under a constant current of 4.5 μA. The robustness of the HiD/CNTs EFE emitter is overwhelmingly superior to that of bare CNTs EFE emitters (τ(CNTs) = 30 min), even though the HiD/Au/CNTs do not show the same good EFE properties as CNTs, which are E0 = 0.73 V/μm and Je = 1.10 mA/cm(2) at 1.05 V/μm. Furthermore, the plasma illumination (PI) property of a parallel-plate microplasma device fabricated using the HiD/Au/CNTs as a cathode shows a high Ar plasma current density of 1.76 mA/cm(2) at an applied field of 5600 V/cm with a lifetime of plasma stability of about 209 min, which is markedly better than the devices utilizing bare CNTs as a cathode. The CNT emitters coated with diamond films possessing marvelous EFE and PI properties with improved lifetime stability have great potential for the applications as cathodes in flat-panel displays and microplasma display devices.
报道了通过两步微波等离子体增强化学气相沉积工艺在金修饰的碳纳米管/硅（Au/CNTs/Si）上涂覆混合颗粒结构金刚石（HiD）薄膜来提高碳纳米管（CNTs）的寿命稳定性。HiD/Au/CNTs发射体的电子场发射（EFE）特性显示，在5.0 V/μm的外加电场下，开启场（E0）低至3.50 V/μm，发射电流密度（Je）高达0.64 mA/cm²。在4.5 μA的恒定电流下测试HiD/CNTs EFE发射体时，在τ(HiD/Au/CNTs) = 360 min的时间段内，没有明显的电流降解或波动。HiD/CNTs EFE发射体的稳健性远远优于裸碳纳米管EFE发射体（τ(CNTs) = 30 min），尽管HiD/Au/CNTs的EFE性能不如碳纳米管，在1.05 V/μm时，碳纳米管的E0 = 0.73 V/μm，Je = 1.10 mA/cm²。此外，以HiD/Au/CNTs作为阴极制造的平行板微等离子体装置的等离子体照明（PI）特性显示，在5600 V/cm的外加电场下，氩等离子体电流密度高达1.76 mA/cm²，等离子体稳定性寿命约为209 min，这明显优于以裸碳纳米管作为阴极的装置。涂覆有具有出色EFE和PI性能且寿命稳定性得到改善的金刚石薄膜的碳纳米管发射体，在平板显示器和微等离子体显示装置中作为阴极应用具有巨大潜力。
