| Abstract Scope |
Atomically thin two-dimensional materials (2DM) have an ultimate surface-to-volume ratio. While it helps biosensing and other applications, surface non-uniformities may drastically increase variability of materials properties. Using an example of a vertical 2DM heterostructure comprised of monolayer graphene and single layer flakes of MoS2, we introduce a novel multidimensional optical imaging technique, capable to detect lattice mismatch and work function difference in the heterostructure. Those result in strain and charge transfer and vary optical response at the nanometer scale, hard to detect and study by other characterization tools. Furthermore, the near-field microscopy allows mapping of distribution for doping and strain at sub-diffractional resolution, that correlate with the non-uniform broadening of optical response of the heterostructure. In summary, multidimensional optical nanoscale imaging allows one to understand the physics of electronic response of 2D materials and their heterostructures.
Acknowledgement: partial support from NSF CHE-2032582, CHE-2032601, DMR-1539916 and DMR-2011839. |