论文标题
通过激光光发作可通过子-EV精度看到的工作功能
Work function seen with sub-meV precision through laser photoemission
论文作者
论文摘要
电子发射可以用于测量表面的工作函数。但是，通过热离子，场和光发射技术获得的值的显着数字数通常只有两三个。在这里，我们表明，当应用角度分辨光发射光谱（ARPE）时，数字最高可达五个。这归功于ARPE检测仅沿正常表面的最慢的光电子。通过使用基于激光的源，我们为缓慢的光电子进行了优化的设置，并解决了AU（111）的最慢端截止（111），其清晰度不会因光带或Fermi-Dirac分布而降低。工作功能至少在$ \ pm $ 0.4 MEV之内至少从30到90 K升级，并且表面老化被视为工作功能的MEV偏移。我们的研究对工作函数的第五个重要数字进行了调查。
Electron emission can be utilised to measure the work function of the surface. However, the number of significant digits in the values obtained through thermionic-, field- and photo-emission techniques is typically just two or three. Here, we show that the number can go up to five when angle-resolved photoemission spectroscopy (ARPES) is applied. This owes to the capability of ARPES to detect the slowest photoelectrons that are directed only along the surface normal. By using a laser-based source, we optimised our setup for the slow photoelectrons and resolved the slowest-end cutoff of Au(111) with the sharpness not deteriorated by the bandwidth of light nor by Fermi-Dirac distribution. The work function was leveled within $\pm$0.4 meV at least from 30 to 90 K and the surface aging was discerned as a meV shift of the work function. Our study opens the investigations into the fifth significant digit of the work function.
