Local Electronic Properties of Coherent Single-Layer WS 2 /WSe 2 Lateral Heterostructures.

Autor:	Herbig C; Department of Physics, University of California, Berkeley, California 94720, United States., Zhang C; Department of Physics, University of California, Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.; Kavli Energy NanoScience Institute, University of California, Berkeley, California 94720, United States., Mujid F; Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States., Xie S; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.; School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States.; Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853, United States., Pedramrazi Z; Department of Physics, University of California, Berkeley, California 94720, United States., Park J; Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.; James Franck Institute, University of Chicago, Chicago, Illinois 60637, United States., Crommie MF; Department of Physics, University of California, Berkeley, California 94720, United States.; Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, United States.; Kavli Energy NanoScience Institute, University of California, Berkeley, California 94720, United States.
Jazyk:	angličtina
Zdroj:	Nano letters [Nano Lett] 2021 Mar 24; Vol. 21 (6), pp. 2363-2369. Date of Electronic Publication: 2021 Mar 15.
DOI:	10.1021/acs.nanolett.0c04204
Abstrakt:	Lateral single-layer transition metal dichalcogenide (TMD) heterostructures are promising building blocks for future ultrathin devices. Recent advances in the growth of coherent heterostructures have improved the structural precision of lateral heterojunctions, but an understanding of the electronic effects of the chemical transition at the interface and associated strain is lacking. Here we present a scanning tunneling microscopy study of single-layer coherent TMD heterostructures with nearly uniform strain on each side of the heterojunction interface. We have characterized the local topography and electronic structure of single-layer WS 2 /WSe 2 heterojunctions exhibiting ultrasharp coherent interfaces. Uniform built-in strain on each side of the interface arising from lattice mismatch results in a reduction of the bandgap of WS 2 . By mapping the tunneling differential conductance across the interface, we find type-II band alignment and an ultranarrow electronic transition region only ∼3 nm in width that arises from wave function mixing between the two materials.
Databáze:	MEDLINE
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