Excitation induced asymmetric fluorescence emission in 2D-WS2 quantum dots

Abstract

In this work, we synthesized 3–7 nm diameter tungsten disulfide quantum dots (WS₂ QDs) by pulsed laser ablation in ethanol solvent, and observed strong, stable, excitation independent blue emission. To further verify the luminescence mechanism of WS₂ QDs, EG-WS₂ QDs were prepared using ethylene glycol as a passivating agent in the experiment. Finally, we use theoretical calculations to prove the quantum mechanical mechanism of absorption and fluorescence emission. Theoretical studies have shown that the excellent fluorescence emission of WS₂ QDs is essentially symmetry breaking emission, and this mechanism determines its high fluorescence yield.