Conjugated Oligothienyl Dendrimers Based on a Pyrazino[2,3-g]quinoxaline Core

The synthesis of a new series of conjugated dendrimers based on an electron-accepting core is introduced. The compounds showed broad absorption bands over 300−700 nm and have reduced HOMO−LUMO gaps of 1.7−1.9 eV. Incorporation of these compounds in bulk heterojunction solar cells as electron-donating material along with PC61BM as electron acceptor gave power conversion efficiencies of up to 1.3% for the second-generation dendrimer.