碳纳米管栅极冷阴极结构场发射计算  

Calculation of the field emission for the CNTs array with normal-gated of cold cathode

作　　者：乔宪武[1] 江影[1] 戴剑锋[2] 

机构地区：[1]中国计量学院理学院实验中心,浙江杭州310018 [2]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,甘肃兰州730050

出　　处：《功能材料》2010年第A01期64-66,71,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50873047)

摘　　要：目前通常有两种方法对CNT-FED场发射进行计算,即镜像悬浮球法和解拉普拉斯方程的方法,虽然解拉普拉斯方程的方法比较复杂,但可以计算出完整的CNTs结构空间各点电场情况。通过解拉普拉斯方程的方法研究了CNTs栅极冷阴极这种符合实际情况且有广泛应用前景的结构。计算结果表明,CNTs尖端处电场强度很大,随着半径r的增加,电场强度急剧减小;场增强因子随CNTs长径比的增加而增加,对于长径比一定的CNTs阵列,对应着一个最佳阵列密度;栅极电压对这种CNTs结构的电流密度有很强的控制作用;并且在极板间距变化的情况下得出了CNTs周围电流密度分布;随着栅极电压的增大,CNTs尖端电流密度随之增大,极板间距减小也可提高CNTs尖端电流密度。Usually there are two methods,floating charge sphere method and solving Laplace equation method,have been used to simulate the carbon nanotubes（CNTs） field emission display（CNT-FED） at present.Although solving Laplace equation is difficult,but it could get the electric field and potential distribution of CNT array FED in the whole space.A hexagon pitch CNTs array vertical to the normal-gated of cold cathode FED which would be useful for future application is simulated by solving Laplace equation in this article.The calculated results show that the intensity of the electric field is very strong near the top of the CNTs,and drops abruptly with the increasing of the distance from CNTs.The field enhancement factor increases with the increasing aspect ratio of the CNTs.For CNTs with definite aspect ratio,there are optimum densities that correspond their best field enhancement factor.Emission current density can be control strongly by the gate voltage in this structure,and get the emission current density around the CNTs with the change of the distance between cathode and anode.The biger the gate voltage,the greater the influence of the emission current,and the emission current density（J） were decreased with distance of anode-cathode（d） increase.

关 键 词：碳纳米管阵列 场发射 栅极冷阴极 电流密度 

分 类 号：O44[理学—电磁学]