Infrared interlayer excitons in MoS2/WSe2 van der Waals heterostructures

Abstract

Heterostructures of monolayers of transition-metal dichalcogenides are considered promising for future ultra-thin opto-electronic applications. They also host intriguing basic phenomena like moiré patterns and correlated electronic states. However, their absorption and emission spectra have so far been restricted to wavelengths shorter than 1000 nm, inaccessible to established technologies in the infra-red like silicon photonics. In this talk I will present the ongoing study of interlayer excitons in WSe2/MoS2 heterostructures. Owing to the large band offset between these materials, their heterostructure features an interlayer exciton emitting light around 1200 nm. This may couple photonic technologies in that range (close to the O-band) to the fundamental phenomena in these heterostructure. I will discuss the comprehensive exploration of the fundamental properties of these excitons such as: tunability, momentum assignment, polarization selection rules, lifetimes, moiré physics, etc.