Benzo[1,2-b:4,5-b ']dithiophene-dioxopyrrolothiophen copolymers for high performance solar cells

New donor/acceptor polymers PBDTDPT1 and PBDTDPT2 with alternating benzodithiophene and N-alkylated dioxopyrrolothiophene were synthesized. The new polymers had deep HOMO levels of 5.42 and 5.44 eV for PBDTDPT1 and PBDTDPT2, respectively. A PBDTDPT2 based BHJ solar cell device achieved a PCE of 4.79% and V(oc) of 0.91 V.