[a] chloroform solutions. [b] thin films.

2.3. Photovoltaic properties

OSCs are fabricated with a conventional device structure of ITO/PEDOT:PSS/acceptors:D18/PDINN/Ag to study the photoelectric performance of OC4-4Cl-Ph , OC4-4Cl-Th andOC4-4Cl-C8 . Optimization of the weight ratio between D18 and acceptors, thermal annealing temperature, and additive was performed, for the corresponding optimization process is provided in the supporting information. The OC4-4Cl-C8 based devices can achieve a champion PCE of 16.56% with a good J _sc (24.40 mA cm^-2) and a suitable V _oc (0.90 V) with a high FF (75.10%), which is much higher than that