Hybrid optical layers of PMMA containing different concentrations of CdSe/ZnS core/shell semiconductor quantum dots were fabricated. Their absorption and luminescence showing quantum confinement effects are given. A frequency down-conversion is then obtained. The external quantum efficiency measurement performed on silicon solar cell with and without the down-conversion layers shows that the luminescence induces new charge generation. In addition, Finite Difference Time Domain (FDTD) simulation of organic solar cell shows that, added to the frequency conversion effect, one can expect to have an increase in light confinement when quantum dots are embedded in the active layer.