The applications were carried out by coating ARCs on the surface of CIGS solar cells but the Ag contact electrodes for measure. Fig.9 shows the current–voltage (I–V) characteristic of the CIGS devices coated with ARCs comparing with the uncoated CIGS sample, and the measured photovoltaic parameters are listed in Table 2. For ARCs coated CIGS solar cell with size of 0.4 cm2,a short-circuit photo current density (Jsc) of 35.12mA/cm 2 with an open-circuit voltage (Voc) of 520.8mV, a calculated fill factor (FF) of 66.40% and an overall PCE (η) of 12.15% have been obtained. As expected, by introducing ARCs, the PCE of CIGS solar cell is increased comparing with that of uncoated cells from 11.20% to 12.15%. The Jsc is increased from 33.36mA/cm2 to 35.12mA/cm2, which can be analyzed as definitely arising from the generation of more photonics with suitable energy that could be absorbed by the CIGS layer. Voc is mainly related to electrical factors, such as built-in electric field, or device quality including coverage of CdS, defects type and concentration. However, Voc is also affected by introduction of ARCs and become a little largerdue to more generated photonics. The external quantum efficiency of TiO2–SiO2 stack coated CIGS solar cells comparing with the responding uncoated CIGS solar cells was investigated, and the increase with a value of approximate 9–11% in the visible range indicates an improved collection of photonics. The results indicate that ARCs are useful to couple more solar incidence into the CIGS solar cells in the same conditions of illumination as the uncoated cells, and therefore enhance the photo- voltaic performance of CIGS solar cells. The utilization of TiO2–SiO2 stack coating reveals superiority and importance to capture solar energy as an outstanding antireflection material with low cost, practicable fabrication and high potential for practical applications.