Coulomb engineering of the bandgap and excitons in two-dimensional materials

Abstract The ability to control the size of the electronic bandgap is an integral part of solid-state technology. Atomically thin two-dimensional crystals offer a new approach for tuning the energies of the electronic states based on the unusual strength of the Coulomb interaction in these materials and its environmental sensitivity. Here, we show that by engineering the surrounding dielectric environment, one can tune the electronic bandgap and the exciton binding energy in monolayers of WS 2 and WSe 2 by hundreds of meV. We exploit this behaviour to present an in-plane dielectric heterostructure with a spatially dependent bandgap, as an initial step towards the creation of diverse lateral junctions with…

• NS
  National Science Foundation

  Awards: DMR-1124894, DGE-1144155, DMR-1420634, 1069240, 1124894, DGE-1069240, 1420634, 1144155
• SR
  Semiconductor Research Corporation
• DF
  Deutsche Forschungsgemeinschaft

  Awards: CH 1672/1, 1672/1-1, CH 1672/1-1, GRK1570
• CN
  Conselho Nacional de Desenvolvimento Científico e Tecnológico
• KE
  Kwanjeong Educational Foundation
• FL
  Fundação Lemann
• DA
  Defense Advanced Research Projects Agency
• MR
  Materials Research Science and Engineering Center, Harvard University

  Awards: 1420634, DMR-1420634
• CS
  Ciência sem Fronteiras
• DO
  Division of Materials Research

  Awards: DMR-1420634, DMR-1124894, 1420634
• DO
  Division of Graduate Education

  Awards: DGE-1069240, 1144155, DGE-1144155, 1069240
• SN
  SLAC National Accelerator Laboratory