New paper in APL Materials!


Growth of ultra-flat ultra-thin alkali antimonide photocathode films

W. G. Stam, M. Gaowei, E. M. Echeverria, K. Evans-Lutterodt,  J. Jordan-Sweet, T. Juffmann, S. Karkare, J. Maxson, S. J. van der Molen, C. Pennington, P. Saha, J. Smedley, R. M. Tromp

ALP Mater. 12, 061114 (2024)

DOI: 10.1063/5.0213461


Ultra-flat, ultra-thin alkali antimonide photocathodes with high crystallinity can exhibit high quantum efficiency and low mean transverse energy of outgoing electrons, which are essential requirements for a variety of applications for photocathode materials. Here, we investigate the growth of Cs3Sb on graphene-coated 4H–SiC (Gr/4H–SiC), 3C–SiC, and Si3N4 substrates. Sb is deposited using pulsed laser deposition, while Cs is deposited thermally and simultaneously. We demonstrate, employing x-ray analysis and quantum efficiency measurements, that this growth method yields atomically smooth Cs3Sb photocathodes with a high quantum efficiency (>10%), even in the ultra-thin limit (<30 nm). For the Si3N4 substrate, film growth is shown to be polycrystalline, while films grown on Gr/4H–SiC show a high degree of ordering with signs of epitaxy.


Congratulations to Guido for the great paper!