To enhance the power conversion efficiency (PCE) of organic solar cells (OSCs), it is essential to precisely regulate the morphology of the bulk-heterojunction (BHJ) active layer to achieve ideal domain size and purity. This study investigates the various solid additives with different chemical structures on the characteristics and device performance of the BHJ active layer. We focus to analyze the correlation between the chemical structure of these additives and the electrical behavior of the devices, including current density-voltage (J-V) characteristics, external quantum efficiency (EQE), and dark current. Ultimately, this research targets improved charge extraction efficiency and maximized PCE through the implementation of optimized solid additives