In this theoretical study, we employ first-principles calculations to explore the bonding nature of organic dyes on the semiconducting MoS2 surface. To achieve good bonding interaction and charge transfer, the -COO center dot residue needs to form ionic bonds with the defected MoS2 surface. In the cases of L0 and a newly synthesized dye named as TN1, we observe the manifestation of an in-gap state at -1 eV from the Fermi level, which might enhance photon trapping capability of the complex. (C) 2016 Elsevier B.V. All rights reserved.