标题： 化学计量和非化学计量铯钾锑化物光电阴极：对光发射性质的第一性原理见解 显示英文标题

标题： Stoichiometric and Non-stoichiometric Cesium Potassium Antimonide Photocathodes: Ab-initio Insights into its Properties for Photoemission

摘要： 碱金属锑化物，特别是铯-钾-锑化物（CsK2Sb），由于其低功函数、快速响应、高量子效率以及在可见光下工作的能力，是直线加速器中下一代光电阴极的有力候选材料。 在本研究中，第一性原理方法用于研究与CsK2Sb的光发射性能相关的结构、电子、光学和表面特性。 我们的结果表明，CsK2Sb在可见光范围内有强烈的吸收，这与实验观察结果一致。 计算出的稳定表面的功函数明显低于常用的金属光电阴极。 这种材料表现出电子迁移率111.86 cm²/Vs和空穴迁移率3.24 cm²/Vs。 由于实际材料中固有地包含本征缺陷，我们分析了CsK2Sb中的本征点缺陷，并确定铯和钾空位最有可能存在。 这些缺陷引入了中间带态，改变了吸收光谱，并可能显著影响光发射行为。 这项工作为优化CsK2Sb用于高效光电阴极应用提供了有价值的见解。 显示英文摘要

摘要： Alkali-metal antimonides, especially cesium-potassium-antimonide (CsK2Sb), are strong candidates for next-generation photocathodes in linear accelerators due to their low work-function, fast response, high quantum yield, and ability to operate under visible light. In this study, first-principles methods are used to examine the structural, electronic, optical, and surface properties of CsK2Sb relevant to its photoemission performance. Our results for CsK2Sb show strong absorption in the visible range consistent with experimental observations. The computed work-functions for the stable surfaces are significantly lower than the commonly used metallic photocathodes. This material exhibits electron and hole mobilities of 111.86 cm2/Vs and 3.24 cm2/Vs, respectively. Since real materials inherently contain intrinsic defects, we analyze native point defects in CsK2Sb and identified Cs and K vacancies as most likely. These defects introduce mid-gap states, modify the absorption spectrum, and may significantly influence photoemission behavior. This work provides valuable insights into optimizing CsK2Sb for high-efficiency photocathode applications.