Dynamics of Correlated Materials
Dynamics of Correlated Materials
Emmy Noether Group Laurenz Rettig
Emmy Noether Group Laurenz Rettig

News Post
New Preprint: Observation of interfacial Meitner-Auger energy transfer
Aug 2021

Interlayer charge- and energy transfer processes in atomically thin, layered van der Waals heterostructures are of fundamental importance for determining their properties in novel device concepts based on single active crystalline layers. In our recent preprint (arXiv link) we study the ultrafast excitation, relaxation and transfer processes in an epitaxial grown monolayer WSe2/graphene heterostructure using time- and angle-resolved photoemission spectroscopy. By measuring the non-equilibrium electronic structure, we identify a novel interfacial energy transfer mechanism: Meitner-Auger energy transfer, which describes the conversion of an exciton in the semiconductor to an intraband electron-hole pair in graphene, characterized by the excitation of deep-lying valence holes in graphene. Based on a systematic microscopic calculation of interlayer couplings, we identify Meitner-Auger energy transfer as the dominant transfer process surpassing the efficiency of the established Förster- and Dexter-type transfer.