利用水热法制备了菊花状的氧化锌纳米棒, 并进行表征, 将纳米氧化锌掺入纳米金刚石中配制成电泳液, 超声分散后电泳沉积到钛衬底上, 再经热处理后进行场发射特性的测试.结果表明：未掺混的金刚石阴极样品的开启电场为7.3 V/μm, 在20 V/μm的电场下, 场发射电流密度为81 μA/cm2;掺混后阴极样品的场发射开启电场降低到4.7~6.0 V/μm, 在20 V/μm电场下, 场发射电流密度提高到140~158 μA/cm2.原因是纳米ZnO掺入后, 增强了涂层的电子输运能力、增加了有效发射体数目, 提高了场增强因子β, 而金刚石保证了热处理后涂层与衬底的良好键合, 形成了欧姆接触, 降低了场发射电流的热效应.场发射电流的稳定性随掺混ZnO量的增加而下降, 要兼顾场发射电流密度及其稳定性, 适量掺入ZnO可有效提高纳米金刚石的场发射性能.

Chrysanthemum-like Zinc Oxide (ZnO) nanorods was fabricated and characterized by hydrothermal route, the diamond was mixed to prepare electrophoretic fluid. After electrophoretic fluid was dispersed by ultrasonic cleaning machine, the coatings were deposited on titanium substrates. Field emission characteristics were tested after heat treatment. Results show that turn-on field of undoped diamond cathode is 7.3 V/μm and field emission current density is 81 μA/cm2 when electric field is set at 20 V/μm, while the doped samples show low turn-on field of 4.7~6.0 V/μm and high field emission current density of 140~158 μA/cm2. The reason is that after the interfusion of nano-ZnO, the electron transport capacity of coating is enhanced, the number of effective emitters increase and field enhancement factor β is improved. Because of diamond, the good bonding between coating and substrate is guaranteed after heat treatment and ohmic contact is formed, which reduces the thermal effect of field emission current. The stability of field emission current declines with the increasing amount of mixed ZnO. Both field emission current density and its stability should be considered, so mixing an appropriate amount of ZnO with nano-diamond can effectively improve field emission characteristics.