Highly efficient small molecule solar cells fabricated with non-halogenated solvents

Though much progress has been achieved for bulk-heterojunction (BHJ) organic solar cells (OSCs), the best performing devices are processed with halogenated solvents. However, the halogenated solvents should be replaced for the practical applications of OSCs due to the toxicity of halogenated solvents to human beings and the environment. In this study, OSCs based on a porphyrin small molecule are fabricated with toluene and o-xylene, which show high PCEs up to 5.46% and 5.85%, respectively. Both PCEs are the highest for small molecule-based OSCs processed with non-halogenated solvents, demonstrating that porphyrin small molecules are very promising for solar cell commercial applications.