The copper-indium-sulfide (CIS) ternary colloids were synthesized in "green" water solvent at room temperature employing mercapto-alkyl carboxylic linker molecules such as thioglycolic acid (TGA), thioacetic acid (TAA), 2-mercaptopropionic acid (2-MPA) and L-cysteine (Cys). The stability of the CIS colloids is strongly influenced by the structures of linker molecules, and short linker molecules induce strong adsorption of the CIS colloids on the TiO2, exhibiting strong visible-light absorption and high photo-conductivities. Effects of linker molecules capping CIS colloids on the solar cell performances were demonstrated. The solar cell performances for the CIS-TiO2 improve as an increase of photoconductivity of the CIS-TiO2 electrodes. In particular, the CIS(TAA)-TiO2 photoelectrode employing the shortest linker molecules (TAA) exhibited the highest PCE yielding with 6.33% (short-circuit current: 14.0 mA/cm(2), open-circuit voltage: 0.91 V and fill factor: 48.0%). (C) 2018 Elsevier Inc. All rights reserved.