False luminescence of molybdenum disulfide quantum dots from carbon dots

Abstract

For the first time, a systematical investigation has been carried out to verify luminescent molybdenum disulfide quantum dots (MoS₂ QDs). We found that the well-reported blue fluorescence of the so-called “MoS₂ QDs” is mainly originated from the co-present carbon based dots rather than MoS₂. Furthermore, the band gap of MoS₂ is independent of the lateral size, and it is impossible to obtain luminescent MoS₂ QDs by reducing the lateral size.