We investigate excitons in stacked transition-metal dichalcogenide layers under a perpendicularly applied electric field, herein MoSe2/WSe2 van der Waals heterostructures (vdWHs). Band structures are obtained with density functional theory (DFT), along with electron and hole wave functions in conduction and valence bands, respectively. A minimal continuum model, parametrized by the DFT results, is presented, allowing for the calculation of the excitonic states. Although the type-II nature of the heterostructure leads to a fully charge separated interlayer exciton on the ground states, our results show that moderate values of electric field produce more evenly distributed wave functions along the vdWH, namely, hybrid inter/intralayer exciton states, where both the interlayer exciton binding energy and, most notably, its oscillator strength are enhanced.
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Acknowledgments. Discussions with J. Kunstman, D. R. Reichman, and C. W. Wong are gratefully acknowledged. A.C. has been financially supported by CNPq, through the PRONEX/FUNCAP and PQ programs. J.A. and T.L. acknowledge support from NSF ECCS-1542202. We acknowledge computational support from the Minnesota Supercomputing Institute (MSI).
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