Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Chem Phys. 2019 Nov 14;151(18):184702. doi: 10.1063/1.5126343.
Electron transport is of fundamental importance and has application in a variety of fields. Different scattering mechanisms affect electron transport in the condensed phase; hence, it is important to comprehensively understand these mechanisms and their scattering cross sections to predict electron transport properties. Whereas electron transport is well understood for high kinetic energy (KE) electrons, there is a discrepancy in the experimental and theoretical values for the Inelastic Mean Free Path (IMFP) in the low KE regime. In this work, velocity map imaging soft X-ray photoelectron spectroscopy is applied to unsupported organic nanoparticles (squalene) to extract experimental values of inelastic and elastic mean free paths (EMFPs). The obtained data are used to calculate corresponding scattering cross sections. The data demonstrate a decrease in the IMFP and increase in the EMFP with increasing electron KE between 10 and 50 eV.
电子输运具有重要的基础性意义，并在多个领域有着应用。不同的散射机制会影响凝聚相中的电子输运；因此，全面了解这些机制及其散射截面，对于预测电子输运性质非常重要。尽管人们对高动能（KE）电子的电子输运有较好的理解，但在低 KE 区，非弹性平均自由程（IMFP）的实验值和理论值之间存在差异。在这项工作中，速度映射成像软 X 光光电电子能谱被应用于无载体有机纳米粒子（角鲨烯），以提取非弹性和弹性平均自由程（EMFPs）的实验值。所获得的数据被用于计算相应的散射截面。数据表明，在 10 到 50 eV 的电子 KE 范围内，IMFP 减小，EMFP 增加。
