Synthesis and characterization of novel conjugated polymer based on indacenetetraone as the electron acceptor and its photovoltaic properties

Abstract

The donor-conjugated polymer named PBDT-IDE-BOT has been successfully synthesized and characterized for inverted polymer solar cell (iPSC). The polymer compromise benzodithiophene (BDT) as donor unit, indacenetetraone (IDE) as acceptor unit, and butyl octyl thiophene (BOT) as π-bridge. The polymer shows broad absorption, and its optical band gap of PBDT-IDE-BOT was 1.64 eV. The HOMO and LUMO energy level of PBDT-IDE-BOT were −5.18 and −3.57 eV, respectively. We fabricated the iPSCs based on PC71BM, ITIC, and Y6BO. The inverted PSC based on PBDT-IDE-BOT/PC71BM, PBDT-IDE-BOT/ITIC, and PBDT-IDE-BOT/Y6BO showed a power conversion efficiency (PCE) of 2.05, 0.5, and 0.19%, respectively.