Azadipyrromethene-Based Zn(II) Complexes as Nonplanar Conjugated Electron Acceptors for Organic Photovoltaics

The effectiveness of new a electron acceptor for organic solar cells is demonstrated. The acceptor is a homoleptic zinc(II) complex of 2,6-diphenylethynyl-1,3,7,9-tetraphenylazadipyrromethene. The high power-conversion efficiency obtained is attributed to the acceptor's 3D structure, which prevents crystallization and promotes a favourable nanoscale morphology, its high V-oc, and its ability to contribute to light harvesting at 600-800 nm.