High temperature photoelectron emission and surface photovoltage in semiconducting diamond
High temperature photoelectron emission and surface photovoltage in semiconducting diamond
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DOI：
10.1063/1.4893274
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发表时间：
2014-08
影响因子：
4
通讯作者：
G. T. Williams;S. Cooil;O. R. Roberts;S. Evans;D. Langstaff;D. Evans
中科院分区：
文献类型：
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作者：
G. T. Williams;S. Cooil;O. R. Roberts;S. Evans;D. Langstaff;D. Evans
在X射线和UV照射期间，在高于环境温度的半导体金刚石中产生非平衡光电压，其对表面电导率敏感。适度掺杂的p型金刚石（111）表面的H-终端维持高达700 K的表面光电压，而干净的（2 × 1）重构表面没有受到严重影响。由300 K测量的平带C1 s结合能为283.87 eV。由高温测量确定的H端表面的真实值为（285.2 ± 0.1）eV，对应于费米能级以下1.6eV的价带顶。这与重建的（2 × 1）表面类似，尽管该表面显示出在285.2和285.4 eV之间的结合能的更宽范围。通过在300 K和1200 K之间的退火循环期间应用的实时光电子能谱，实现光电压量化和校正。一个模型，占测得的表面光电压的温度依赖性电阻。一个大的，高温的光电压，是敏感的表面电导率和光子通量，提出了一种新的方式来使用适度的B掺杂金刚石在基于电压的传感设备。
A non-equilibrium photovoltage is generated in semiconducting diamond at above-ambient temperatures during x-ray and UV illumination that is sensitive to surface conductivity. The H-termination of a moderately doped p-type diamond (111) surface sustains a surface photovoltage up to 700 K, while the clean (2 × 1) reconstructed surface is not as severely affected. The flat-band C 1s binding energy is determined from 300 K measurement to be 283.87 eV. The true value for the H-terminated surface, determined from high temperature measurement, is (285.2 ± 0.1) eV, corresponding to a valence band maximum lying 1.6 eV below the Fermi level. This is similar to that of the reconstructed (2 × 1) surface, although this surface shows a wider spread of binding energy between 285.2 and 285.4 eV. Photovoltage quantification and correction are enabled by real-time photoelectron spectroscopy applied during annealing cycles between 300 K and 1200 K. A model is presented that accounts for the measured surface photovoltage in terms of a temperature-dependent resistance. A large, high-temperature photovoltage that is sensitive to surface conductivity and photon flux suggests a new way to use moderately B-doped diamond in voltage-based sensing devices.