Resolution characteristics of graded doping and graded composition transmission-mode AlGaAs/GaAs photocathodes.
Resolution characteristics of graded doping and graded composition transmission-mode AlGaAs/GaAs photocathodes.
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DOI：
10.1364/ao.54.001414
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发表时间：
2015-02
期刊：
影响因子：
1.9
通讯作者：
Wenjuan Deng;J. Zou;Xincun Peng;Lin Feng;Zhifu Zhu;Weilu Wang;Yijun Zhang;Benkang Chang
中科院分区：
文献类型：
--
作者：
Wenjuan Deng;J. Zou;Xincun Peng;Lin Feng;Zhifu Zhu;Weilu Wang;Yijun Zhang;Benkang Chang
从二维连续方程出发，对梯度掺杂和梯度成分传输模式AlGaAs/GaAs光电阴极的分辨模型进行了数值求解。根据该模型，计算了不同梯度掺杂和梯度组成结构的理论调制传递函数（MTF）。仿真结果表明，梯度成分和梯度掺杂结构都能提高光电阴极的分辨率。在可能的梯度掺杂和梯度成分光电阴极中，指数掺杂和线性成分光电阴极具有最大的分辨率。分辨率的提高是由于梯度组合物或梯度掺杂结构引起的内置电场。仿真结果还表明，AlGaAs/GaAs阴极的MTFs随AlGaAs层厚度的减小或入射光波长的增加而增大。
The resolution model of a graded doping and graded composition transmission-mode AlGaAs/GaAs photocathode is solved numerically from the two-dimensional continuity equations. According to the model, we calculate the theoretical modulation transfer function (MTF) of different graded doping and graded composition structures. The simulation results show that both graded composition and graded doping structures can increase the resolution of the photocathode. The exponentially doping and linear composition photocathode has the maximum resolution among the possible graded doping and graded composition photocathodes. The resolution improvement is attributed to the built-in electric field induced by a graded composition or graded doping structure. The simulation results also show that the MTFs of AlGaAs/GaAs cathodes increase as the AlGaAs layer thickness decreases, or the incident light wavelength increases.