Deciphering the rich photoluminescence spectrum of monolayer WSe₂.

High-quality monolayer WSe₂ samples when gated and encapsulated by hBN exhibit unprecedented rich photoluminescence spectrum. In this talk, I will summarize what we (think we) already understand, identifying the signatures of dark and indirect excitons as well as of dark trions, along with their zone-center and zone-edge phonon replicas. I will then focus on the signatures of many-body interactions, proposing novel electron-assisted optical transitions of dark excitons and the brightening of these excitons when they are coupled to collective charge or spin excitations (plasmons and magnons). I will explain why these many-body interactions have the right conditions to manifest in the photoluminescence spectra of electron-doped tungsten-based monolayers.