Preprint article · Journal article
Interlayer Excitons and Band Alignment in MoS2/hBN/WSe2 van der Waals Heterostructures
van der Waals heterostructures (vdWH) are ideal systems for exploring light-matter interactions at the atomic scale. In particular, structures with a type-II band alignment can yield detailed insight into carrier-photon conversion processes, which are central to, for example, solar cells and light-emitting diodes.
An important first step in describing such processes is to obtain the energies of the interlayer exciton states existing at the interface. Here we present a general first-principles method to compute the electronic quasi-particle (QP) band structure and excitonic binding energies of incommensurate vdWHs.
The method combines our quantum electrostatic heterostructure (QEH) model for obtaining the dielectric function with the many-body GW approximation and a generalized 2D Mott-Wannier exciton model. We calculate the level alignment together with intra- and interlayer exciton binding energies of bilayer MoS2/WSe2 with and without intercalated hBN layers, finding excellent agreement with experimental photoluminescence spectra.
A comparison to density functional theory calculations demonstrates the crucial role of self-energy and electron-hole interaction effects.
Language: | English |
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Publisher: | American Chemical Society (ACS) |
Year: | 2017 |
Pages: | 938-945 |
ISSN: | 15306992 and 15306984 |
Types: | Preprint article and Journal article |
DOI: | 10.1021/acs.nanolett.6b04275 |
ORCIDs: | Latini, Simone , Olsen, Thomas and Thygesen, Kristian Sommer |