Solvent engineering for strong photoluminescence enhancement of monolayer molybdenum disulfide in redox-active molecular treatment

Abstract

Monolayer molybdenum disulfide's (MoS2) direct band gap nature makes it a good platform for realizing atomically thin optoelectronic devices. However, an issue is its low luminescence brightness. In this research, we demonstrate a strategy to achieve strong photoluminescence (PL) of monolayer MoS2, by treatment with a redox-active molecule, fluoranil. An important finding is that the factor of PL enhancement depends strongly on the solvent used and the PL changes by more than one order of magnitude. This work is useful for harnessing the strong optical properties of MoS2 by the combination of oxidizing molecules and engineering the solvent used.