Direct C–H Arylation-Derived Donor Polymers Afford PCEs over 10% for Organic Solar Cells

Abstract

Direct C−H arylation polymerization (DArP) using unfunctionalized C−H bonds as a coupling partner has emerged as a sustainable synthetic strategy toward π-functional polymers with minimized waste emissions and potentially having comparable optoelectronic performances with the polymers derived from the C−Sn bond-based Stille couplings. However, most of the reported DArP-derived π-polymers used in bulk heterojunction organic solar cells (OSC) still deliver power conversion efficiencies (PCEs) below 10%. In this work, the PBDB-T2F (i.e., PM6) polymer was synthesized, for the first time, by the tin-free DArP under optimized conditions, which affords a PCE up to 10.1% for OSC devices. Although the systematical comparison study by varied characterizations including gel permeation chromatography, UV−vis spectroscopy, BHJ devices, microscopies, and grazing incidence X-ray diffraction reveals that the DArP strategy still needs to be improved in terms of reactivity and regioselectivity compared to the Stille couplings, the preliminary yet promising results here obtained will provide the stimulus for the generalization of DArP to the atom-economic synthesis of high-performance πpolymers, and promote the integration of green chemistry with green energy.

Effect of surfactant type on oxygen barrier behavior of polyvinyl alcohol/α‐zirconium phosphate nanocomposites

“…The slight increase in crystallization temperature and crystallinity can be attributed to the ability of ZrP to partially serve as a nucleating agent and partially hinders the ability of PVA to fold into crystalline structure at low concentration (≤2.4 vol %). When a higher concentration (>2.4 vol %) of ZrP is introduced in PVA, the strong molecular scale interaction between ZrP and PVA significantly reduces the molecular mobility of PVA surrounding ZrP, leading to the reduction in crystallization temperature and crystallinity 50 . The above findings are also similarly observed in PVA and graphene oxide nanocomposites 51 .…”

Advancing Integration of Direct C–H Arylation-Derived Star-Shaped Oligomers as Second Acceptors for Ternary Organic Solar Cells

“…Till now, the two most common approaches for creating π-functional materials with a sp 2 C–C skeleton are the Stille and Suzuki reactions which include organometallic coupling partners. As part of these reactions, the coupling of C–M/C–Br occurs, where M might be either B or Sn. − In order to create reliable, economical, and time-saving ways to produce UNFRAs, it is essential to tackle these reactions to avoid the prefunctionalization of C–M bonds. − Direct C–H arylation (DACH), also known as C–H/C–Br cross-coupling, is becoming more popular as a way to formulate organic semiconductor compounds, − owing to its outstanding benefits, including atom- and step-economy, simplified techniques, low environmental impact, and cost-effectiveness. The importance of DACH in OSC research stems from the fact that it is used in the synthesis of a wide variety of oligomers, including linear and nonlinear ones, as well as star oligomers, and polymeric and molecular materials. − …”

Perylene-diimide for organic solar cells: current scenario and prospects in molecular geometric, functionalization, and optoelectronic properties

“…21–29 Additionally, very recently, researchers have developed n-type small molecular acceptors because NFA polymeric material is difficult to purify, has reduced solubility, is hard to characterize with an undefined molecular weight, and has low infiltration into the nanostructured material. 30–36 Depending on the degree of dispersion, they exhibit the organic small molecules used in OSCs can be classified as either monodispersed small molecules or polydispersed small molecules. This article offers up-to-the-minute insights into recently discovered organic molecular small molecule PDI variations; for example, methodologies that are necessary to enable possible scalable applications of OSCs.…”