Photoluminescence enhancement of aluminum ion intercalated MoS₂ quantum dots

Low photoluminescence (PL) quantum yield of molybdenum disulfide (MoS2) quantum dots (QDs) has limited practical application as potential fluorescent materials. Here, we report the intercalation of aluminum ion (Al3+) to enhance the PL of MoS2 QDs and the underlying mechanism. With detailed characterization and exciton dynamics study, we suggest that additional surface states including new emission centers have been effectively introduced to MoS2 QDs by the Al3+ intercalation. The synergy of new radiative pathway for exciton recombination and the passivation of non-radiative surface traps is responsible for the enhanced fluorescence of MoS2 QDs. Our findings demonstrate an efficient strategy to improve the optical properties of MoS2 QDs and are important for understanding the regulation effect of surface states on the emission of two dimensional sulfide QDs.