Atomically smooth films of CsSb: a chemically robust visible light photocathode

作     者：Parzyck, C.T. Pennington, C.A. DeBenedetti, W.J.I. Balajka, J. Echeverria, E. Paik, H. Moreschini, L. Faeth, B.D. Hu, C. Nangoi, J.K. Anil, V. Arias, T.A. Hines, M.A. Schlom, D.G. Galdi, A. Shen, K.M. Maxson, J.M. 

作者机构：Laboratory of Atomic and Solid State Physics Department of Physics Cornell University IthacaNY14853 United States Cornell Laboratory for Accelerator-Based Sciences and Education Cornell University IthacaNY14853 United States Department of Chemistry and Chemical Biology Cornell University IthacaNY14853 United States  Cornell University IthacaNY14853 United States School of Electrical & Computer Engineering University of Oklahoma NormanOK73019 United States Center for Quantum Research and Technology University of Oklahoma NormanOK73019 United States Department of Materials Science and Engineering Cornell University IthacaNY14853 United States Kavli Institute Cornell for Nanoscale Science Cornell University IthacaNY14853 United States Leibniz-Institut für Kristallzüchtung Max-Born-Straße 2 Berlin12489 Germany Department of Industrial Engineering University of Salerno SA Fisciano84084 Italy 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2023年

核心收录：

主　　题：Electronic structure 

摘      要：Alkali antimonide semiconductor photocathodes provide a promising platform for the generation of high brightness electron beams, which are necessary for the development of cutting-edge probes including x-ray free electron lasers and ultrafast electron diffraction. However, to harness the intrinsic brightness limits in these compounds, extrinsic degrading factors, including surface roughness and contamination, must be overcome. By exploring the growth of CsxSb thin films monitored by in situ electron diffraction, the conditions to reproducibly synthesize atomically smooth films of CsSb on 3C-SiC (100) and graphene coated TiO2 (110) substrates are identified, and detailed structural, morphological, and electronic characterization is presented. These films combine high quantum efficiency in the visible (up to 1.2% at 400 nm), an easily accessible photoemission threshold of 550 nm, low surface roughness (down to 600 pm on a 1 µm scale), and a robustness against oxidation up to 15 times greater then Cs3Sb. These properties suggest that CsSb has the potential to operate as an alternative to Cs3Sb in electron source applications where the demands of the vacuum environment might otherwise preclude the use of traditional alkali antimonides. © 2023, CC BY-NC-SA.