Author: Attenkofer, K.
Paper Title Page
TUPSO76 In Situ Characterization of ALKALI Antimonide Photocathodes 403
 
  • J. Smedley, K. Attenkofer, S.G. Schubert
    BNL, Upton, Long Island, New York, USA
  • I. Ben-Zvi, X. Liang, E.M. Muller, M. Ruiz-Osés
    Stony Brook University, Stony Brook, USA
  • M. DeMarteau
    Fermilab, Batavia, USA
  • H.A. Padmore, J.J. Wong
    LBNL, Berkeley, California, USA
  • A.R. Woll
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J. Xie
    ANL, Argonne, USA
 
  Funding: The authors wish to acknowledge the support of the US DOE, under Contract No. KC0407-ALSJNT-I0013, DE-AC02-98CH10886 and DE-SC0005713. Use of CHESS is supported by NSF award DMR-0936384.
Alkali antimonide photocathodes are a prime candidate for use in high-brightness photoinjectors of free electron lasers and 4th generation light sources. These materials have complex growth kinetics - many methods exist for forming the compounds, each with different grain size, roughness, and crystalline texture. These parameters impact the performance of the cathodes, including efficiency, intrinsic emittance and lifetime. In situ analysis of the growth of these materials has allowed investigation of correlations between cathode structure and growth parameters and the resulting quantum efficiency (QE). The best cathodes have a QE at 532 nm in excess of 6% and are structurally textured K2CsSb with grain sizes in excess of 20 nm. X-ray reflection (XRR) has been used to characterize the roughness evolution of the cathode, while X-ray Diffraction (XRD) has been used to characterize the texture, grain size and stoichometry.