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URLhttps://doi.org/10.18429/JACoW-IPAC2024-MOPR79
TitleDemonstration of enhanced quantum efficiency from optical interference in alkali antimonide photocathodes
Authors
  • C. Pennington, E. Echeverria
    Cornell University (CLASSE)
  • A. Galdi
    Università degli Studi di Salerno
  • J. Maxson
    Cornell University
  • J. Smedley
    SLAC National Accelerator Laboratory
  • K. Mondal, K. Evans-Lutterodt, M. Gaowei
    Brookhaven National Laboratory
  • P. Bhattacharyya, S. Karkare
    Arizona State University
AbstractWe present measurements of quantum efficiency (QE) modulations in CsSb and Cs3Sb photocathodes that arise from optical interference of reflections from the underlying substrate that has multiple semi-transparent layers. The photocathode films are grown on a cubic silicon carbide layer (3C-SiC) which itself is grown epitaxially on Si(100) during fabrication. We find that the QE modulates by up to a factor of two over a laser wavelength range of 30 nm, and that a modulation peak can be tuned to coincide with a desired laser wavelength by changing the thicknesses of both the photocathode and the silicon carbide layer in the substrate. A model for the QE modulations is derived and fitted to QE measurements of CsSb and Cs3Sb films, which have different indices of refraction, in addition to QE measurements of Cs3Sb films grown on 3C-SiC substrates with two different silicon carbide layer thicknesses. Good agreement is found between the model and measurements, confirming the optical interference effect can be exploited to enhance quantum efficiency at desired visible wavelengths.
Paperdownload: MOPR79.pdf
CiteBibTeX, LaTeX, Text/Word, RIS, EndNote
Conference15th International Particle Accelerator Conference
Series
LocationNashville, TN
Date19-24 May 2024
PublisherJACoW Publishing, Geneva, Switzerland
Editorial BoardFulvia Pilat - Oak Ridge National Laboratory Wolfram Fischer - Brookhaven National Laboratory Robert Saethre - Oak Ridge National Laboratory Petr Anisimov - Los Alamos National Laboratory Ivan Andrian - Elettra-Sincrotrone Trieste S.C.p.A.
Online ISBN978-3-95450-247-9
Online ISSN2673-5490
Received17 May 2024
Revised23 May 2024
Accepted23 May 2024
Issued01 July 2024
DOI10.18429/JACoW-IPAC2024-MOPR79
Pages634-637