Increased photoelectron transmission in High-pressure photoelectron spectrometers using "swift acceleration"
Increased photoelectron transmission in High-pressure photoelectron spectrometers using "swift acceleration"
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DOI：
10.1016/j.nima.2015.02.047
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发表时间：
2015-06
影响因子：
1.4
通讯作者：
M. Edwards;P. Karlsson;S. Eriksson;M. Hahlin;H. Siegbahn;H. Rensmo;J. Kahk;I. Villar-García;D. Payne;John Åhlund
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文献类型：
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作者：
M. Edwards;P. Karlsson;S. Eriksson;M. Hahlin;H. Siegbahn;H. Rensmo;J. Kahk;I. Villar-García;D. Payne;John Åhlund
在装有Al - k - α x射线源的高压x射线光电子能谱（HPXPS）系统上，评价了高压x射线光电子能谱分析仪的一种新的工作模式。在不同的样品气体环境（n2和H2O）下测量了各种金属箔样品（金、银和铜），前孔径直径为0.8 mm。新的设计理念是基于光电子通过分析仪前孔径后“迅速”加速到几个keV的动能。与标准模式相比，在标准模式下，前两个孔之间的前部分是无场的，这提供了更宽的角度收集和更低的电子损失趋势，在与分析仪内气体分子的碰撞中。在快速加速模式下，根据实验条件，真空中峰值强度可提高约3倍，在6-9毫巴范围内峰值强度可提高约10至20倍，具体取决于动能。这些实验结果与分析仪的模拟传输函数吻合得很好。新的操作模式使数据采集比标准操作模式更快，在家庭实验室环境中特别有价值。通过在2mbar的水气氛下测量染料敏化太阳能电池光电极的价带结构，进一步证明了性能，这是光电化学器件中感兴趣的分子修饰表面。
A new operation mode of a HPXPS (high-pressure X-ray photoelectron spectroscopy) analyzer is evaluated on a HPXPS system fitted with an Al Kα X-ray source. A variety of metal foil samples (gold, silver and copper) were measured in different sample gas environments (N2and H2O), and a front aperture diameter of 0.8 mm. The new design concept is based upon “swiftly” accelerating the photoelectrons to kinetic energies of several keV after they pass the analyzer front aperture. Compared to the standard mode, in which the front section between the two first apertures is field-free, this gives a wider angular collection and a lower tendency for electron losses in collisions with gas molecules within the analyzer. With the swift-acceleration mode we attain, depending on the experimental conditions, up to about 3 times higher peak intensities in vacuum and about 10 to 20 times higher peak intensities in the 6–9 mbar regime, depending on kinetic energy. These experimental findings agree well with simulated transmission functions for the analyzer. The new mode of operation enables faster data acquisition than the standard mode of operation, particularly valuable in a home laboratory environment. Further demonstrations of performance are highlighted by measurements of the valence band structure in dye-sensitized solar cell photoelectrodes under a 2 mbar H2O atmosphere, a molecularly modified surface of interest in photoelectrochemical devices.