Danovich, M. and Ruiz-Tijerina, D. A. and Hunt, R. J. and Szyniszewski, M. and Drummond, N. D. and Fal'ko, V. I. (2018) Localized interlayer complexes in heterobilayer transition metal dichalcogenides. Physical review B, 97: 195452. ISSN 1098-0121
1802.06005.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (2MB)
Abstract
We present theoretical results for the radiative rates and doping-dependent photoluminescence spectrum of interlayer excitonic complexes localized by donor impurities in MoSe2/WSe2 twisted heterobilayers, supported by quantum Monte Carlo calculations of binding energies and wave-function overlap integrals. For closely aligned layers, radiative decay is made possible by the momentum spread of the localized complexes' wave functions, resulting in radiative rates of a few μs−1. For strongly misaligned layers, the short-range interaction between the carriers and impurity provides a finite radiative rate with a strong asymptotic twist angle dependence ∝θ−8. Finally, phonon-assisted recombination is considered, with emission of optical phonons in both layers resulting in additional, weaker emission lines, redshifted by the phonon energy.