Electrically tunable Γ–Q interlayer excitons in twisted MoSe2 bilayers

Abstract

Twist, the very degree of freedom in van der Waals heterostructures, offers a compelling avenue to manipulate and tailor their electrical and optical characteristics. In particular, moiré patterns in twisted homobilayer transition metal dichalcogenides (TMDs) lead to zone folding and miniband formation in the resulting electronic bands, holding the promise to exhibit inter-layer excitonic optical phenomena. Although some experiments have shown the existence of twist-angle-dependent intra- and inter-layer excitons in twisted MoSe2 homobilayers, electrical control of the interlayer excitons in MoSe2 is relatively under-explored. Here, we show the signatures of the moiré effect on intralayer and interlayer excitons in 2H-stacked twisted MoSe2 homobilayers. Doping- and electric field-dependent photoluminescence measurements at low temperatures give evidence of the momentum-direct K–K intralayer excitons, and the momentum-indirect Γ–K and Γ–Q interlayer excitons. Our results suggest that twisted MoSe2 homobilayers are an intriguing platform for engineering interlayer exciton states, which may shed light on future atomically thin optoelectronic applications.