LPCVD法制备碳纳米管薄膜及其场发射性能的研究

采用低压化学气相沉积法(LPCVD)在镍片上直接制备碳纳米管(CNTs)薄膜,系统地研究了生长温度(500~800℃)对碳纳米管薄膜形貌、结构及场发射性能的影响,并对此方法的生长机理进行了分析。当温度从500℃升高到650℃时,碳纳米管的生长速率随着温度升高而增大,而温度继续上升,速率则明显减小。利用扫描电镜(SEM)和拉曼光谱仪表征和检测了碳纳米管薄膜的形貌和结构。碳纳米管的管径、长度、一致性和晶化程度随温度都有明显的变化。同时还对碳纳米管薄膜的场发射特性进行了测试,对其场发射机理进行了深入地探讨,表明温度对碳纳米管的性能有很大影响,并存在最优化的温度条件。实验结果表明碳纳米管薄膜的形貌、结构及其场发射性能可通过生长温度进行一定范围的控制。

Deposition of Carbon Nanotubes Film by LPCVD and Related Field Emission Property

Carbon nanotubes (CNTs) were directly grown on nickel substrates by low pressure chemical vapor deposition (LPCVD) using acetylene-hydrogen as precursor. The reaction temperature was in the range of 500～800 ℃. Temperature effects on the growth and morphology of CNTs and their field emission properties were investigated. The growth rate of CNTs increased first with temperature increase from 500 ℃, and reached a maximal value at 650 ℃, then decreased when the temperature increased further. The morphologies and structures of deposited CNTs were characterized by scanning electron microscope and Raman spectroscopy. The diameter, length, uniformity and crystallinity of the deposited CNT also showed a temperature dependence. The field emission properties of the CNTs were tested, the field emission principle was studied deeply, and the results proved the temperature dependence of CNTs properties and the existance of optimization of temperature. The experimental result indicated that the morphology, structure and field emission properties of CNTs could be controlled by the reaction temperature in a certain range.