A structural analysis of ordered Cs₃Sb films grown on single crystal graphene and silicon carbide substrates

Autor(en)

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

Abstrakt

Alkali antimonides are well established as high efficiency, low intrinsic emittance photocathodes for accelerators and photon detectors. However, conventionally grown alkali antimonide films are polycrystalline with surface disorder and roughness that can limit achievable beam brightness. Ordering the crystalline structure of alkali antimonides has the potential to deliver higher brightness electron beams by reducing surface disorder and enabling the engineering of material properties at the level of atomic layers. In this report, we demonstrate the growth of ordered Cs3Sb films on single crystal substrates 3C-SiC and graphene-coated 4H-SiC using pulsed laser deposition and conventional thermal evaporation growth techniques. The crystalline structures of the Cs3Sb films were examined using reflection high energy electron diffraction and x-ray diffraction diagnostics, while film thickness and roughness estimates were made using x-ray reflectivity. With these tools, we observed ordered domains in less than 10 nm thick films with quantum efficiencies greater than 1% at 530 nm. Moreover, we identify structural features such as Laue oscillations indicative of highly ordered films. We found that Cs3Sb films grew with flat, fiber-textured surfaces on 3C-SiC and with multiple ordered domains and sub-nanometer surface roughness on graphene-coated 4H-SiC under our growth conditions. We identify the crystallographic orientations of Cs3Sb grown on graphene-coated 4H-SiC substrates and discuss the significance of examining the crystal structure of these films for growing epitaxial heterostructures in future experiments.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Cornell University, Brookhaven National Laboratory, Università degli Studi di Salerno, Max F. Perutz Laboratories GmbH (MFPL), Arizona State University, Leiden University, SLAC Natl Accelerator Lab, IBM T. J. Watson Research Center

Journal

APL Materials

Band

13

Anzahl der Seiten

9

ISSN

2166-532X

DOI

https://doi.org/10.48550/arXiv.2407.12224

Publikationsdatum

01-2025

Peer-reviewed

Ja

ÖFOS 2012

103018 Materialphysik

ASJC Scopus Sachgebiete

Allgemeine Materialwissenschaften, Allgemeiner Maschinenbau

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d11b81ad-aab5-4022-909c-470a23fdb772