Efficient Polymer Solar Cells with Open-Circuit Voltage of 1.01 V and Power Conversion Efficiency of 8.09%

[Image: see text] A series of polymer solar cells (PSCs) were prepared with different solvent additive 1-chloronaphthalene (CN) doping volume ratio to adjust the phase separation of active layers. The optimized PSCs exhibit a power conversion efficiency (PCE) of 8.09%, along with an open-circuit voltage of 1.01 V, a short circuit current density of 13.64 mA cm(–2), and a fill factor of 58.70%. All the key photovoltaic parameters of PSCs can be simultaneously increased by incorporating 1.0 vol % CN in blend solutions due to the optimized phase separation of active layers assisted by the volatilization of CN. Over 24% PCE improvement can be obtained by incorporating 1.0 vol % CN, indicating that the dynamic process of film forming should play the vital role in determining the performance of PSCs.