To increase the performance of thin-film solar cells, the solar spectrum splitting technique has been considered and studied. It was found from simulations that the total efficiency of nearly 25% can be obtained at the splitting wavelength of 600 nm with the top cell using higher band gap material. Experiments have been carried out to verify the simulation results. Up to now the total efficiency of about 22.0% has been obtained using a-Si:H and Cu(In1-x,Ga-x)Se-2 as the top and bottom cells, respectively, at the splitting wavelength of 614 nm which is similar to the simulation results. This result shows that our developed splitting technique is promising for high-performance thin-film solar cells. (C) 2013 Elsevier B.V. All rights reserved.