A single-junction InGaP solar cells with polystyrene (PS) nanospheres on the surface has been developed. The self-assembly of PS nanospheres is one of the simplest and the fastest methods with which to build a 2D closely packed periodic structure. Based on the scattering of the PS nanospheres, the light path length can be increased. As compared to the InGaP solar cells without PS nanospheres on the top surface the standard process. An increase short-circuit current form 8.93% to 10.31% is improved when a single-junction InGaP solar cells with PS nanospheres. The conversion efficiency measured can also be improved from 8.79% to 9.71%. The single-junction InGaP solar cell with PS nanospheres was achieved.