[23p-B103-1~13] 12.5 Organic solar cells

[23p-B103-4] Novel nonfullerene acceptors based on benzimidazole moieties for organic photovoltaics

〇(M1)Shohei Ohno¹, Tsubasa Mikie¹, Itaru Osaka¹ (1.Hiroshima Univ.)

Keywords:Organic photovoltaics, Nonfullerene acceptor, Organic Semiconductor

Recently, the power conversion efficiency of organic photovoltaics (OPVs) has been rapidly improved owing to the development of nonfullerene acceptors. Here, we designed and synthesized a series of new acceptors OBIA-n, in which the sulfur atom of the benzothiadiazole moiety in the benchmark acceptor Y6 was replaced with the carbon atom to form the benzimidazole moiety. OBIA-n had a slightly higher HOMO energy level and a slightly narrower bandgap than Y6 due to the electronic effects of carbon. We then fabricated OPV cells by combining with PM6 as the donor. Interestingly, the efficiency of the cells was improved by increasing the bulkiness of the substituents of OBIA-n.