Quantum efficiency of transmission-mode AlxGa1−xAs/GaAs photocathodes with graded-composition and exponential-doping structure
Quantum efficiency of transmission-mode AlxGa1−xAs/GaAs photocathodes with graded-composition and exponential-doping structure
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DOI：
10.1016/j.optcom.2016.02.034
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发表时间：
2016-06
影响因子：
2.4
通讯作者：
Cheng Feng;Yijun Zhang;Y. Qian;Yuan Xu;Xinxin Liu;G. Jiao
中科院分区：
文献类型：
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作者：
Cheng Feng;Yijun Zhang;Y. Qian;Yuan Xu;Xinxin Liu;G. Jiao
为了最大限度地提高阴极性能，研制了一种透射式AlxGa1−xAs/−光电阴极，它采用成分梯度的AlxGa1 GaAsxAs窗口层和指数掺杂的GaAs光发射层。通过求解一维连续性方程，结合三步模型，推导出了这种含有两重内建电场的复杂结构的量子效率理论模型。通过对不同成分和掺杂结构的光电阴极光谱特性的比较，以及对阴极结构参数的分析，发现双内置电场可以有效地改善AlxGa1GaAsxAs/−光电阴极的光电发射性能，这与Al的比例变化范围以及窗口层和发射层的厚度有关。量子效率模型将为透射式梯度带隙光电阴极的优化设计提供理论指导。
A transmission-mode AlxGa1−xAs/GaAs photocathode with the combination of composition-graded AlxGa1−xAs window layer and exponential-doping GaAs emission layer is developed to maximize the cathode performance. The theoretical quantum efficiency model with this complex structure containing twofold built-in electric fields is deduced by solving the one dimensional continuity equations combined with the three-step model. By comparison of spectral characteristics of photocathodes with different composition and doping structures, and through analysis of cathode structure parameters, it is found that the twofold built-in electric fields can effectively improve photoemission performance of AlxGa1−xAs/GaAs photocathode, which is related to Al proportion variation range and thicknesses of window layer and emission layer. The quantum efficiency model would provide theoretical guidance for better design of transmission-mode graded bandgap photocathodes.