Low temperature, non-halogen solvent processed single-component organic solar cells with 10% efficiency

A double-cable conjugated polymer DCPIC-BO is designed via introducing a long-branched alkyl chains 2-buthyloctyl into the acceptor side unit. Compared with the double-cable polymer (DCPIC-EH) with the 2-ethylhexyl alkyl chains, the solubility of the DCPIC-BO in non-halogen solvents is substantially improved. Therefore, a power conversion efficiency (PCE) of 9.77% can be obtained by the devices processed from o-xylene at 40 °C, while the DCPIC-EH cannot be processed due to its poor solubility under this condition. Moreover, PCEs of 10.10% for small-area (0.04 cm2) devices and nearly 9% for devices with an area of 1 cm2 were achieved using a non-halogenated solid additive in o-xylene, realizing the "absolutely halogen-free" OSC fabrication.