Luminescent solar concentrator (LSC) integrated with c-Si photovoltaic cells (PV cells) in building integrated photovoltaics (BIPV) could grow up to be an important element of our life for energy harvest in the future. Heavy metal free quantum dots (QDs) are promising for LSC applications, which can be controlled to possess effective large Stokes Shift and low reabsorption of emission that benefit their applications in BIPV. In our work, different amount and size of SiO2 particles were added to CuInS2/ZnS QDs based LSCs to realize highly efficient scattering enhanced LSC (S-LSC) devices. Since SiO2 particles induced scattering effect, we achieved a power conversion efficiencies (PCE) of 4.20%, which showed an improvement of 60.3% compared with the pure QDs based LSC without SiO2 particles. This study suggests a new method of scattering enhancement to realize better performance for LSC.