High-energy interlayer exciton ensembles in MoSe 2 /WSe 2 heterostructures by Laguerre–Gaussian excitation

Abstract We reveal the higher energetic luminescence part of interlayer exciton ensembles in MoSe 2 /WSe 2 heterostructures upon excitation by an optical Laguerre–Gaussian mode. The excitation is achieved with the help of a spatial light modulator giving rise to a ring-shaped distribution of interlayer excitons. A hyperspectral analysis of the exciton photoluminescence suggests that the excitation scheme allows the accumulation of high-energetic excitons in the rings’ center. Since the exciton luminescence exhibits a negligible variation of the energetic blue shift of the emission energy as a function of intensity across the rings, we can exclude spatially varying exciton-exciton interactions and a local phase-space filling of lower exciton states to be the dominant underlying process. An incomplete thermalization and an inward propagation of non-thermalized excitons consistently explain the accumulation of high-energetic excitons in the rings’ center.