Recently it has been shown that despite a large lattice mismatch, a completely relaxed epitaxial film can be grown on weakly interacting substrates. This has opened up many new opportunities to grow functional semiconductor films for diverse applications that were not possible in the past. In this talk, I will present a superlattice area matching model to predict the orientation of the incommensurate film with respect to the substrate orientation. In addition, I will show that these films can often be detached from the substrates to form free standing films for flexible electronic applications. As an example, I will present our recent results of epitaxial Sb2Se3 on mica [1] and graphene for solar cell application. Both challenges and opportunities will be discussed.

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Acknowledgements

This work was supported by the Empire State Development’s Division of Science, Technology, and Innovation (NYSTAR, United States) through Focus Center-New York contract C150117 and Rensselaer, United States. We acknowledge MNCR staff at RPI for, in part, facilitating the experimental work.

References

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[1] X. Wen, Z. Lu, G.-C. Wang, M.A. Washington, T.-M. Lu, Efficient and stable flexible Sb2Se3 thin film solar cells enabled by an epitaxial CdS buffer layer, Nano Energy, 85 (2021) 106019, https://www.sciencedirect.com/science/article/pii/S2211285521002779.