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

Abstract

The realization of π-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-π-extended/deficient BOD-IPY 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-π-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 πacceptor electronic/structural properties with meso-π-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 π-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-πextension strategy to realize BODIPYs with favorable π-acceptor properties, and our findings could open up future materials design avenues in various organic optoelectronic applications.

Buried‐Contact Organic Field‐Effect Transistor: The Way of Alleviating Drawbacks from Interfacial Charge Transfer

“…These findings suggest that the PA process, which had no significant effect on the molecular crystalline rearrangement, contributed to improving the film crystallinity when applied concurrently with thermal energy. Figure S2 (Supporting Information) presents the 1D plots in the out‐of‐ and in‐plane directions for the 2D GIXD data shown in Figure 3d; the full‐width‐at‐half‐maximum (FWHM) of the (200) peak obtained in the out‐of‐plane direction was used to calculate the crystallite size using the Scherrer equation [ 42–44 ] (see Figure 3e). For the pristine PBTTT film and the film formed via the PA process, the average diameters of the crystallites were ≈142 and 145 nm, respectively, consistent with the previous descriptions.…”

Organoboron-embedded functional materials: recent developments in photovoltaic and luminescence properties

“…It is noteworthy that the aforementioned materials function as p-type semiconductors in field effect transistors and demonstrate enhanced carrier mobility. Apart from their contribution to the architecture of BODIPY-based organic photovoltaic materials, this study also unveils novel prospects for future applications of these materials 115. 2.3.3.…”

Polymers in High-Efficiency Solar Cells: The Latest Reports

“…Can et al recently synthesized low bandgap (1.30–1.35 eV) D-A copolymers 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as donor part and benzo[1,2-b:4,5-b′]dithiophene (BDT) acting as acceptor. The highest conversion efficiency of 4.40% was shown by P(T2BDY−TBDT), having a very high current density of 12.07 mAcm −2 [ 141 ].…”