Simultaneous spin-coating and solvent annealing: Manipulating the active layer morphology to a power conversion efficiency of 9.6% in polymer solar cells
Here, we developed a simultaneous spin-coating/solvent-annealing process and demonstrated morphology optimization for PTB7 based organic photovoltaics. This novel processing method enhances the edge-on crystalline content in thin films and induces the formation of weak PCBM aggregates. As a result, the efficiency of polymer solar cells increased from 9.2% to a certified high efficiency of 9.61%, owing to an enhanced short-circuit current (J sc , 18.4 mA cm –2 vs. 17. 5 mA cm –2 ) and an improved fill factor.