影响碳纳米管阴极场发射性能首要因素的研究

On the Principal Factors Effecting the Properties of Carbon Nanotube Cathodes

研究了影响碳纳米管(CNT)场发射性能的主要因素,通过实验分析气压、热处理温度、发射体尺寸参数等,发现预先热处理可有效提高发射体分散均匀性,而高温后处理可有效纯化CNT;气压和温度是工作过程中影响CNT阴极膜场发射稳定性的重要参数;而CNT发射体的长度、管径与膜层密度是影响场发射电流特性的主要因素,长径比大小影响着场增强因子大小,大长径比引起低的开启电场强度和高发射电流,但管径的大小与场发射均匀性的优劣呈相反关系。

Principal factors influencing field emission of CNTs are investigated.Via the analysis of the gas pressure and the temperature of heat treatment as well as the profile parameters of emitters,it is observed that uniform dispersion of CNTs could be achieved by high temperature pre-treatment,while post-treatment for CNT films could purify the films.Gas pressure and temperature in operation process seriously affect the stability of field emission.Furthermore,length,diameter and density of CNTs are primary factors to influence the field emission characteristics.Field emission factor is dependent on the aspect ratio,the bigger the aspect ration is,the lower turn-on electric field and high emission current are.However,CNTs shows inverse correlation between diameter of tube and luminescence uniformity.