This study reports the synthesis of boron-doped CQDs (B-CQDs) and the using as a novel additive for organic solar cells. we introduced B-CQDs P3HT:PCBM bulk heterojunction organic solar cells (OSCs). The structural and morphological characterization results showed that the optical absorption and film crystallinity can be easily enhanced by B-CQDs additive in P3HT:PCBM solution. Additionally, with the improved crystallinity of P3HT, the effective interchain interaction and phase separation in photoactive layer were achieved. As a result, ~50% improving of FF of the device with 5 vol% of B-CQDs additive was determined. Thanks to improved photovoltaic characteristics, best performing device showed a power conversion efficiency of 2.7% (with ~50% improvement). This report shows that the addition of optimized vol% of B-CQDs into the photoactive blend strongly improves the absorption and leads to achieve efficient charge separation and transport in OSCs.