Quantitative Photoemission Predictions of Semiconducting Photocathodes from Many-Body Ab Initio Theory
Carl von Ossietzky Universität Oldenburg（奥尔登堡卡尔·冯·奥西茨基大学）；Friedrich-Schiller Universität Jena（耶拿弗里德里希·席勒大学）；Helmholtz-Zentrum Berlin（柏林赫尔姆霍兹中心）；Universität Siegen（锡根大学）；Humboldt-Universität zu Berlin（柏林洪堡大学）；Universitá degli Studi di Salerno（萨莱诺大学）
Richard Schier, Chen Wang, Jonas Dube, Julius Kühn, Alice Galdi, Thorsten Kamps, Caterina Cocchi
The development of high-performance electron sources requires theoretical frameworks that accurately link the microscopic electronic properties of cathode materials to their macroscopic photoemission observables. Here, we present a many-body extension of the three-step photoemission model for semiconducting photocathodes, directly integrating the $GW$ approximation and the solution of the Bethe-Salpeter equation on top of density functional theory (DFT). This approach overcomes the intrinsic limitations of standard DFT by explicitly accounting for quasiparticle and excitonic effects in the photoexcitation process. The quantum efficiency (QE) is evaluated by combining the ab initio absorption with an emission probability derived as an exciton-weighted average. We validate this model on representative alkali antimonides and demonstrate that a qualitative many-body description successfully captures complex spectral features that empirical models fail to reproduce. Furthermore, by incorporating macroscopic optical effects such as thin-film interference and polarization via Fresnel post-processing, we achieve quantitative agreement with experimental QE values without any adjustment. Minor discrepancies near the photoemission threshold are attributed to the idealized surface barrier adopted in the model and impurity effects in the samples, highlighting specific directions for future refinements. This work establishes a robust, parameter-free ab initio tool that bridges microscopic electronic correlation with macroscopic observables, providing a critical pathway for the rational design of next-generation electron sources.
Electron escape probability in high-efficiency photocathodes measured by reverse-injection photovoltage
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院列扎诺夫半导体物理研究所）；Novosibirsk State University（新西伯利亚国立大学）；Novosibirsk State Technical University（新西伯利亚国立技术大学）
Semiconducting Electronic Structure of the Ferromagnetic Spinel $\mathbf{Hg}\mathbf{Cr}_2\mathbf{Se}_4$ Revealed by Soft-X-Ray Angle-Resolved Photoemission Spectroscopy
Elucidating Na$_2$KSb band structure: near-band-gap photoemission spectroscopy and DFT calculations
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院罗扎诺夫半导体物理研究所）；Novosibirsk State University（新西伯利亚国立大学）；Institute of Strength Physics and Materials Science, Russian Academy of Sciences（俄罗斯科学院强度物理与材料科学研究所）；JSC “EKRAN FEP”（叶卡捷琳堡电子仪器联合股份公司（JSC EKRAN FEP））；Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院博列斯科夫催化研究所SKIF同步辐射设施）；Novosibirsk State Technical University（新西伯利亚国立技术大学）
Revealing the (111) surface electronic structure of epitaxially grown Na$_2$KSb photocathode
Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院列扎诺夫半导体物理研究所）；Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院博列斯科夫催化研究所）；Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences（俄罗斯科学院西伯利亚分院强度物理学与材料科学研究所）；Ioffe Institute（约费物理技术研究所）；JSC "EKRAN FEP"
Bulk and surface electronic structure of Bi$_4$Te$_3$ from $GW$ calculations and photoemission experiments
我们提出了一个结合的理论和实验研究的电子结构的化学计量比Bi $_4$ Te $_3$，一个自然的超晶格交替Bi $_2$ Te $_3$五重层和Bi双层。与相关的半导体化合物Bi $_2$ Te $_3$和Bi $_1$ Te $_1$相比，密度泛函理论预测Bi $_4$ Te $_3$是半金属。在多体微扰理论的$GW$近似下，我们计算了Bi $_4$ Te $_3$的准粒子电子结构.准粒子修正被发现修改的费米能附近的价带和导带的色散，导致一个小的间接带隙的开放。通过对$_4$的本征态分析，将其归类为具有体拓扑不变量$\mathbb{Z}_2$（1;111）和磁镜陈数$n_M=1$的对偶拓扑绝缘体.体$GW$结果被用来建立一个基于Wannier函数的紧束缚哈密顿量，进一步应用于研究（111）表面的电子性质。与我们的角度分辨光电发射测量的比较显示出良好的协议之间的计算和测量的表面状态，并表明双拓扑性质的Bi $_4$ Te $_3$。
