Energy Structure in Photoelectric Emission from Cs-Covered Silicon and Germanium
Energy Structure in Photoelectric Emission from Cs-Covered Silicon and Germanium
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DOI：
10.1103/physrev.144.558
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发表时间：
1966-04
期刊：
影响因子：
--
通讯作者：
F. G. Allen;G. Gobeli
中科院分区：
文献类型：
--
作者：
F. G. Allen;G. Gobeli
给出了硅和锗的清洁解理和铯覆盖的（111）面的光电产额和能量分布。铯的单层降低了每个的功函数到1.6 eV，并揭示了详细的结构在产量和分布。这种结构是直接相关的反射率和硅中的主要功能同意与Brust，科恩，和菲利普斯的理论计算预测，假设直接跃迁的能带模型由赝势方法。从极端的n型到p型的不同的体掺杂产生能量分布和产率的变化引起的带弯曲的变化引起的表面之下。这种能带弯曲效应对于硅比对于锗强得多。它的结论是，激发主要是一个直接的体积过程和发射的电子起源于平均深度范围从20 μ m到几百μ m的电子能量从6到3 eV以上的价带最大值。
Photoelectric yield and energy distributions are given for clean-cleaved and cesium-covered (111) surfaces of silicon and germanium. A monolayer of cesium lowers the work function of each to∼ 1.6 eV and reveals detailed structure in both yield and distributions. This structure is directly related to that seen in reflectivity and the major features in silicon agree well with those predicted by theoretical calculations of Brust, Cohen, and Phillips, assuming direct transitions in an energy-band model derived by the pseudopotential method. Varying bulk doping from extreme n to p type produces large changes in energy distributions and yield caused by the changes in band bending induced just beneath the surface. Such band-bending effects are much stronger for silicon than for germanium. It is concluded that excitation is predominantly a direct volume process and that emitted electrons originate from a mean depth ranging from 20 Å to several hundred Å as the electron energy varies from 6 to 3 eV above the valence-band maximum.