Enhancing photoluminescence (PL) of single-layer (1L) MOS2 is essential to its application as thinnest and high efficient light-emitting devices in the near future. Here, we report an unusual enhanced PL intensity of charged exciton (trion) using p-type aromatic molecules. Calculation of the quantum yield using exciton dynamics indicates that this enhancement of trion is dominant by weakening the non-radiative combination to intrinsic defects. Our research further extends the previous theory and a better understanding of exciton transition in 1L MoS2 is revealed. (C) 2015 Elsevier B.V. All rights reserved.