First-principles investigation of structural, electronic and optical properties of cubic K2CsSb with different surface orientations. (15th November 2022)

• Record Type: Journal Article
• Authors: Wang, Xingchao; Zhang, Kaimin; Jin, Muchun; Ren, Ling; Han, Yunfeng; Wang, Qilong; Zhang, Yijun
• Is Part Of: Solid state communications. Volume 356(2022)
• Publication Date: 2022-11-15
• Subjects: K2CsSb photocathode -- First-principles -- Electronic structures -- Optical properties; Solid state chemistry -- Periodicals; Solid state physics -- Periodicals; Chimie de l'état solide -- Périodiques; Physique de l'état solide -- Périodiques; 530.41
• DOI: 10.1016/j.ssc.2022.114960
• Languages: English
• ISSNs: 0038-1098

Abstract

Abstract: The bi-alkali antimonide photocathodes have been widely applied in the fields of fast-speed photodetection and high-energy physics. To guide the preparation of high-sensitive K2 CsSb photocathode, by first-principles calculations based on density functional theory, the electronic and optical properties of cubic K2 CsSb surface models with different surface orientations and atomic terminations are investigated. More specifically, the properties including surface geometry structures, electronic structure, optical properties, work function and surface energies of the (100) K-terminated, (100) Cs Sb-terminated, (111) Cs-terminated and (111) K-terminated and (110) surfaces are analyzed to determine the surface with superior photoemission performance. It is found that the (111) Cs-terminated surface exhibits the highest conductivity and the lowest work function, indicating its best emission ability, meanwhile, the lowest surface energy and Gibss free energy show its best structural stability and thermodynamic stability. Moreover, the (111) Cs-terminated surface with the advisable optical properties in the photon energy range of 3.1–3.2 eV, is conducive to the improvement of quantum efficiency, which makes it favorable for radiation detection from scintillators. Graphical abstract: Image 1 Highlights: K2 CsSb surface models of different orientations and atomic terminations are studied. Cs atoms in the top layer have the greatest trend to move towards the surface. (111) Cs-terminated surface shows its best emission ability and structural stability. (111) Cs-terminated surface has the advisable absorption coefficient and reflectivity.