Photoresponse in a Strain-Induced Graphene Wrinkle Superlattice

J Phys Chem Lett. 2020 Jul 2;11(13):5059-5067. doi: 10.1021/acs.jpclett.0c01535. Epub 2020 Jun 17.

Abstract

Applied strain introduces significant changes in the carbon-carbon bond of graphene and thereby forms electronic superlattices. The electron/phonon coupling and existence of pseudogauge fields within these superlattices render unique electronic and magnetism properties. However, the interfacial interactions between strained and pristine graphene have rarely been studied. Herein, we report a prominent increase in photocurrent at the interface between pristine graphene and the strain-induced superlattice (i.e., the graphene wrinkle). The photocurrent distribution indicates a large increase in the bending lattice of graphene. These results demonstrate that the photocurrent enhancement is due to the difference in the Seebeck coefficient between pristine graphene and deformed superlattices, resulting in a significant increase in the photothermoelectric effect at the interface.