Meso-pi-Extended/Deficient BODIPYs and Low-Band-Gap Donor-Acceptor Copolymers for Organic Optoelectronics


CAN A. , Choi G., ÖZDEMİR R. , Park S., Park J. S. , Lee Y., ...More

ACS APPLIED POLYMER MATERIALS, vol.4, no.3, pp.1991-2005, 2022 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 4 Issue: 3
  • Publication Date: 2022
  • Doi Number: 10.1021/acsapm.1c01856
  • Title of Journal : ACS APPLIED POLYMER MATERIALS
  • Page Numbers: pp.1991-2005
  • Keywords: conjugated polymers, BODIPY, organic solar cells, organic semiconductors, LUMO, POLYMER SOLAR-CELLS, CHANNEL SEMICONDUCTORS, MECHANICALLY ROBUST, CONJUGATED POLYMERS, ELECTRON-DONOR, ENERGY-LEVELS, PERFORMANCE, POLY(3-HEXYLTHIOPHENE), THIAZOLE

Abstract

The realization of pi-deficient acceptors and their donor-acceptor copolymers has become a key research focus for the realization of versatile organic optoelectronic materials and devices. Herein, we demonstrate the theoretical design, synthesis, and physicochemical/optoelectronic characterization of two meso-pi-extended/deficient BODIPY building blocks (2OD-T2BDY and 2OD-TTzBDY) and a library of donor-acceptor copolymers with low band gap (E-g = 1.30-1.35 eV) based on these building blocks. These building blocks, to the best of our knowledge, are the first examples of BODIPYs with meso-pi-extension. A library of BODIPY building blocks with varied meso units/substituents is studied to reveal the meso effects on the semiconducting BODIPY's optoelectronic properties. The building blocks showed favorable pi-acceptor electronic/structural properties with meso-pi-delocalized and stabilized LUMOs (ca. -3.6 eV) and large ground-state dipole moments of 4.9-5.5 D. Consistent with the theoretical/experimental pi-electronic structures, all copolymers functioned as p-type semiconductors in field-effect transistors and as donor materials in the bulk heterojunction organic photovoltaics. Power conversion efficiencies of up to 4.4% with a short-circuit current of 12.07 mA cm(-2) were achieved. This study demonstrates a unique meso-pi-extension strategy to realize BODIPYs with favorable pi-acceptor properties, and our findings could open up future materials design avenues in various organic optoelectronic applications.