A study was conducted to demonstrate significant grain size and device performance improvement of the Cu(In,Ga)Se2 (CIGS)-based PV device through the intentional introduction of controlled Sb impurity doping into the CIGS layer film processing. A solution-based spin coating process was used as a deposition method to demonstrate the effect of antimony-doping on the properties of the CIGS films and the solar cell device. The approach relied on forming a soluble molecular-based metal chalcogenide precursor in hydrazine at room temperature, while device-quality CIGS films were easily attained using this process without the need for postdeposition selenization. An additional Sb 2Sb3/S solution in hydrazine was used as Sb source for each CIGS film. The phase purity of the film was also verified with X-ray diffraction.