Evidence for Hybrid Inorganic–Organic Transitions at the WS2/Terrylene Interface

Abstract

The realization of the potential of hybrid inorganic organic systems requires an understanding of the coupling between the constituents: its nature and its strength. The observation of hybrid optical transitions in the monolayer WS2/terrylene hybrid is reported. The first‐principle calculations, linear optical, and transient absorption spectroscopy are employed to investigate the optical spectrum of the hybrid, which exhibits a new transition that does not appear in the constituents’ spectra. The calculations indicate type II level alignment, with the highest occupied level of terrylene in the gap of WS2. Exploiting state‐resolved transient absorption, the response of the hybrid interface to optical excitation is selectively probed. The dynamics reveal rapid hole transfer from WS2 to the terrylene layer, with a decay time of 88 ps. This hole transfer induces a bleach of the hybrid transition, which indicates that terrylene contributes to its initial state. Based on this, the hybrid resonance energy, and on our calculations, we assign the hybrid feature to a transition from the highest occupied molecular orbital of terrylene to the conduction band of WS2 close to the Γ point. The results indicate that the conditions for strong electronic coupling are met in this hybrid system.