A low-cost halogen-free supramolecular additive is reported for the first time, 5-hydroxy-2-methylpyrimidine (ROPD), and has been incorporated into PTB7-Th:PC71BM active layer to promote the processing and power conversion efficiency (PCE)...

Three novel D(A–Ar)2 type small molecules were obtained for application in OSCs. Especially, the Voc, Jsc and FF values for FBT(TDPP-TS)2-based cells were synergistically improved by inserting both N and S atoms onto the terminal groups.