纳米碳管阵列场发射电流密度的理论数值优化  

Theoretical optimization for field emission current density from carbon nanotubes array

作　　者：王新庆[1] 李良[1] 褚宁杰[1] 金红晓[1] 葛洪良[1] 

机构地区：[1]中国计量学院材料科学与工程学院,浙江省磁学重点实验室,杭州310018

出　　处：《物理学报》2008年第11期7173-7177,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10647149,20571067和20601024)资助的课题~~

摘　　要：以纳米碳管阵列为研究对象,利用镜像悬浮球模型及Fowler-Nordheim电流密度公式,对纳米碳管阵列的场发射电流密度进行计算,进而综合考虑场发射增强因子及场发射电流密度对纳米碳管阵列场发射性能进行定量优化.参考碳管阵列场发射电流密度最大值及场发射增强因子,表明当纳米碳管阵列间距为碳管高度十分之一时,纳米碳管阵列的场发射性能得到优化.与以前的理论估算结果相比,优化的阵列间距进一步减小.当纳米碳管间距过大,场发射增强因子增加,而场发射电流密度会在更大程度上减小;当纳米碳管密度较大时,场发射增强因子受到静电屏蔽的影响而急剧下降.With the help of the floating sphere mirror image model and the Fowler-Nordheim equation,the emission current density from carbon nanotube was calculated in this paper.Taking the field enhancement factor and the emission current density into account,the field emission of carbon nanotube array was optimized in theory.The result shoved that the field emission from carbon nanotube array is maximal when the intertube distance is equal to one tenth of the tube height,which is a little smaller than the previous result.When the intertube distance is larger,the field enhancement factor increases,but the emission current density decreases even more rapidly with increasing intertube distance.For carbon nanotube arrays with higher array density,the field enhancement factor decreases greatly with the decreasing intertube distance due to the screening of the electric field.

关 键 词：纳米碳管 场发射 增强因子 电流密度 

分 类 号：TB383.1[一般工业技术—材料科学与工程]