Atomically smooth films of CsSb: A chemically robust visible light photocathode
Abstract
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. Nonetheless, 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 566 nm, low surface roughness (down to 600 pm on a 1 μm scale), and a robustness against oxidation up to 15 times greater than Cs3Sb. These properties lead us to 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 01, 2023
- Source ID
- 10.1063/5.0166334
Entities
People
- Alice Galdi
- Brendan D. Faeth
- C. A. Pennington
- Cheng Hu
- Christopher Parzyck
- Darrell G. Schlom
- Elena Echeverria
- Hanjong Paik
- J. Kevin Nangoi
- J. M. Maxson
- Jan Balajka
- Kyle Shen
- Luca Moreschini
- Melissa A. Hines
- T. A. Arias
- Vivek Anil
- William J I DeBenedetti
Organizations
- Air Force Office of Scientific Research
- Cornell University
- Division of Materials Research
- Leibniz Institute for Crystal Growth
- National Science Foundation
- United States Department of Energy
- University of Oklahoma
- University of Salerno