Achieving over 10% efficiency in P3HT-based organic solar cells via solid additives.

The photovoltaic performance of organic solar cells (OSCs) based on poly(3-hexylthiophene) (P3HT) has been steadily improved by developing novel non-fullerene acceptors (NFAs) in recent years. Herein, to further improve the performance of P3HT-based OSCs, a solid additive (SA4) and a typical solvent additive (DIO) were employed to process P3HT:ZY-4Cl-based OSCs, respectively. In comparison with the DIO-processed device, the SA4-processed one exhibits a more ordered molecular packing and more favorable phase separation, leading to the enhanced charge transport and reduced carrier recombination. As a result, the SA4-processed device delivers a power conversion efficiency (PCE) of 10.24%, which is much higher than that of DIO-processed counterpart (6.26%). This work reported an over 10% of PCE in P3HT-based OSCs for the first time, indicating the promising development of P3HT-based OSCs by morphological modulation.