中文摘要：

采用磁控共溅射法在Si片表面镀NiTi膜作为碳纳米管生长的催化剂,制备出表面形貌特殊的碳纳米管薄膜,如“丘状”和“星状”的表面微结构。通过扫描电子显微镜对碳纳米管薄膜的形貌进行表征,采用二极管形式测试了碳纳米管薄膜的场发射性能。实验结果表明,这两种碳纳米管薄膜都具有优异的场发射性能,10μA/cm^2时的开启电场分别仅为1．02 V/μm和1．15 V/μm,在外加电场为2．4 V/μm时的电流密度分别达到4．32 mA/cm^2和6．88 mA/cm^2。通过场发射FN的曲线计算得到的场发射增强因子分别为10113和6840。这两种碳纳米管薄膜优异的场发射性能与其表面的微结构有关。表面的粗糙结构增强了部分碳纳米管的局域电场,易于发射电子。

英文摘要：

Carbon nanotube （CNT） films with special surface morphology, such as hills-like and stars-like, were synthesized on silicon substrate, and the field emission properties were examined. The nanotubes were fabricated by thermal chemical vapor deposition using co-sputtered NiTi alloy film as catalyst. The hills-like and stars-like CNT films showed good field emission properties of low turn-on electric field and large current density. The turn-on electric field values required to obtain a 10 μA /cm^2 current density for hills-like and stars-like CNT films were determined at about 1.02 V/μm and 1.15 V/μm, respectively. At an applied macroscopic field of 2. 4 V/μm, the current densities reached to 4.32 mA/cm^2 and 6.88 mA/cm^2 , respectively. The field enhancement factor β of hills-like and stars-like CNT films, calculated from the Fowler-Nordheim plots, were about 10 113 and 6 840. The good field-emission behavior is ascribed to the combined effects of the intrinsic field emission of CNT and the rough morphology of the film surface.