Energy distributions of electrons emitted from reflection-mode Cs-covered GaAs photocathodes.
Energy distributions of electrons emitted from reflection-mode Cs-covered GaAs photocathodes.
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DOI：
10.1364/ao.51.007662
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发表时间：
2012-11
期刊：
影响因子：
1.9
通讯作者：
J. Zou;Yijun Zhang;Xincun Peng;Wenjuan Deng;Lin Feng;Benkang Chang
中科院分区：
文献类型：
--
作者：
J. Zou;Yijun Zhang;Xincun Peng;Wenjuan Deng;Lin Feng;Benkang Chang
通过计算到达光电阴极表面的电子能量分布，求解电子隧穿表面势垒的薛定谔方程，得到了基于双极小扩散模型的反射式Cs覆盖GaAs光电阴极发射电子能量分布的计算公式。根据该方程，我们研究了入射光子能量、扩散长度和表面势垒对电子能量分布的影响。利用该方程对实测的电子能量分布曲线进行拟合，得到阴极性能参数。理论曲线中的Γ峰和L峰与实验曲线中的峰一致。拟合的势垒厚度1.7 μ m精确地反映了GaAs-Cs偶极层的厚度。
By calculating the energy distributions of electrons reaching the photocathode surface and solving the Schrödinger equation for an electron tunneling through the surface potential barrier, we have obtained an equation to calculate the energy distributions of electrons emitted from reflection-mode Cs-covered GaAs photocathodes based on a two-minima diffusion model. According to the equation, we studied the effects of incident photon energies, diffusion lengths, and surface potential barrier on the electron energy distributions. The equation was also used to fit the measured electron energy distribution curves and the cathode performance parameters were obtained from the fitting. The Γ and L peaks in the theoretical curves are in agreement with the peaks in the experimental curves. The fitted barrier thickness 1.7 Å exactly reflects the GaAs-Cs dipole layer thickness.