A series of small-molecules (SMs) based on coplanar perylene unit coupled with diketopyrrolopyrrole chromophoric core exhibit broad absorption in the range of 500-800nm and low bandgap energise of 1.6-1.7eV. The power conversion efficiency approximately reach at 0.4% under 1.5G illumination is achieved for organic solar cells based on a small-molecule bulk heterojunction system consisting of SMs as a donor and [6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM) as an acceptor.