Gamma-point interlayer excitons and resonantly hybridised excitons in van der Waals heterostructures
September 2nd, 2019 DANIEL TERRY Manchester University

Interlayer excitons, whereby electrons and holes are localised in adjacent semiconducting layers, form an intriguing area of research that shows promise for exploring exciton condensates as well as other phenomena. Within 2D material research, these interlayer excitons are usually formed between monolayer TMDCs (MoS2, WSe2 etc) with the band alignment suggested to occur at the Brillouin zone edges (K and/or K’ points). Firstly, I will present initial evidence for the creation of interlayer excitons between few-layer TMDCs and PTMCs (GaSe, InSe). These are suggested to form a band alignment at the Brillouin zone centre (Gamma-point). Furthermore, these interlayer excitons appear bright independent of the relative twist angle, with the energy tunable through film thickness selection; presenting exciting new avenues for interlayer exciton research. Secondly, I will present recent developments in the study of resonantly hybridised excitons in a moire superlattice. Here, at low twist angles the interlayer and intralayer excitonic states are suggested to mix (hybridise), enhancing the effect of the moire superlattice on the optical properties of the heterostructure.

Seminar, September 2, 2019, 15:00. ICFO’s Seminar Room

Hosted by Prof. Dmitri Efetov