Effect of Surface Potential Barrier on the Electron Energy Distribution of NEA Photocathodes  

表面势垒形状对NEA光阴极电子能量分布的影响(英文)

作　　者：邹继军[1] 杨智[2] 乔建良[2] 常本康[2] 曾一平[3] 

机构地区：[1]东华理工大学电子工程系,抚州344000 [2]南京理工大学电子工程与光电技术学院,南京210094 [3]中国科学院半导体研究所,北京100083

出　　处：《Journal of Semiconductors》2008年第8期1479-1483,共5页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:60678043);江西省自然科学基金(批准号:2007GQS0412);江西省教育厅科技计划(批准号:GJJ08298)资助项目~~

摘　　要：By calculating the energy distribution of electrons reaching the photocathode surface and solving the Schrodinger equation that describes the behavior of an electron tunneling through the surface potential barrier,we obtain an equation to calculate the emitted electron energy distribution of transmission-mode NEA GaAs photocathodes. Accord- ing to the equation,we study the effect of cathode surface potential barrier on the electron energy distribution and find a significant effect of the barrier-Ⅰ thickness or end height,especially the thickness,on the quantum efficiency of the cath- ode. Barrier Ⅱ has an effect on the electron energy spread, and an increase in the vacuum level will lead to a narrower electron energy spread while sacrificing a certain amount of cathode quantum efficiency. The equation is also used to fit the measured electron energy distribution curve of the transmission-mode cathode and the parameters of the surface barri- er are obtained from the fitting. The theoretical curve is in good agreement with the experimental curve.通过计算电子到达阴极面时的能量分布和求解电子隧穿表面势垒的薛定谔方程得到了透射式NEA GaAs光阴极发射电子能量分布的计算公式.利用该公式仿真研究了阴极表面势垒形状对电子能量分布的影响,发现Ⅰ势垒变化对阴极的量子效率影响显著,其中尤以Ⅰ势垒宽度影响更大,而Ⅱ势垒则影响阴极的能量展宽,其中真空能级的升高可使阴极电子能量分布更集中,但却牺牲了一定的阴极量子效率.拟合分析了实验测试的透射式阴极电子能量分布曲线,实验与理论曲线吻合得很好,并得到了阴极的表面势垒参数.

关 键 词：NEA photocathode surface potential barrier transmission coefficient electron energy distribution quantum efficiency 

分 类 号：TN201[电子电信—物理电子学]