The epitaxial growth of functional materials using a substrate with a graphene layer is a highly desirable method for improving structural quality and obtaining free-standing epitaxial nano-membranes for scientific study, applications, and economical reuse of substrates. However, the aggressive oxidizing conditions typically employed to grow epitaxial perovskite oxides can damage graphene. Here, we demonstrate a technique based on hybrid molecular beam epitaxy that does not require an independent oxygen source to achieve epitaxial growth of complex oxides without damaging the underlying graphene. The technique produces films with self-regulating cation stoichiometry control and epitaxial orientation to the oxide substrate. Furthermore, the films can be exfoliated and transferred to foreign substrates while leaving the graphene on the original substrate. These results open the door to future studies of previously unattainable free-standing nano-membranes grown in an adsorption-controlled manner by hybrid molecular beam epitaxy, and has potentially important implications for the commercial application of perovskite oxides in flexible electronics.
@article{arxiv.2206.09094,
title = {Free-Standing Epitaxial SrTiO$_3$ Nanomembranes via Remote Epitaxy using Hybrid Molecular Beam Epitaxy},
author = {Hyojin Yoon and Tristan K. Truttmann and Fengdeng Liu and Bethany E. Matthews and Sooho Choo and Qun Su and Vivek Saraswat and Sebastian Manzo and Michael S. Arnold and Mark E. Bowden and Jason K. Kawasaki and Steven J. Koester and Steven R. Spurgeon and Scott A. Chambers and Bharat Jalan},
journal= {arXiv preprint arXiv:2206.09094},
year = {2022}
}