Regensburg 2022 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 6: 2D Materials 1 (joint session HL/CPP/DS)
HL 6.6: Vortrag
Montag, 5. September 2022, 11:15–11:30, H36
Investigating Twist Angle Dependence of Exciton Resonances in WSe2/MoSe2 Heterostructures — •Chirag Palekar, Tobias Manthei, Bárbara Rosa, and Stephan Reitzenstein — Institute of Solid State Physics, Technische Universität Berlin, D-10623 Berlin, Germany
Artificially produced TMDC heterostructures (HS) realized by stacking two different TMDC monolayers (ML) are a new class of promising semiconducting heterostructures. Due to their type-II band alignment, TMDC HSs tend to host the spatially indirect interlayer excitons (IX) where electrons and holes are located in conduction and valence bands, respectively, of the different layers. Here we study the twist angle dependence of IX resonances employing micro-photoluminescence excitation (PLE) measurements on twisted WSe2/MoSe2 heterobilayer. PLE measurements reveal anti-correlation between linewidth and emission energy of IX. Resonant excitation at intralayer exciton energies of constituent ML yields high emission intensity of the IX with linewidth narrowing above 10 meV. We measure a drastic reduction in PL emission from IX for twist angles in the range of 10∘- 50∘ due to large interlayer separation. Moreover, we show a noticeable IX exciton resonance separation which increases as function of twist angle i.e. from 0∘ (67 meV) to 24∘ (96 meV) along with observable red shift in IX emission energy. This fundamental study of excitons resonances deepens the current understanding of physics of twisted TMDC heterostructures and paves the way for future experiments and theoretical work.