Ternary Cd 1− x In x Te semiconductor nanoparticles have been demonstrated to be sensitizers for solar cell devices. The chemical bath deposition (CBD) process was used to synthesize Cd 1− x In x Te nanoparticles, which were deposited onto a mesoporous TiO 2 photoelectrode. Individual nanoparticles were estimated to have an average diameter range of ∼10nm. The atomic percentages of chemical elements for Mn 2+ -doped Cd 1− x In x Te show that the structure could be Mn 2+ -doped CdInTe incorporated with CdIn 2 Te 4 structure. The resulted X-ray diffraction and diffraction ring patterns of Mn 2+ -doped Cd 1− x In x Te nanoparticles indicated the structure to be tetragonal. The optical band gaps were also decreased to 0.9eV after Mn 2+ doping, compared with E g =1.47eV for undoped Cd 1− x In x Te(7). The best efficiency of 0.51% under 100 mW/cm 2 (AM 1.5G) was obtained after Mn 2+ doping with a short-circuit current density (J sc ) of 1.71mA/cm 2 , an open-circuit voltage (V oc ) of 0.739V and a fill factor (FF) of 40.2%. This work demonstrated the feasibility of using Cd 1− x In x Te with Mn 2+ doping as a broadband solar absorber for TiO 2 photoelectrodes.