Regioregular polymerized small-molecule acceptors for high-performance all-polymer solar cells

Abstract

All-polymer solar cells (all-PSCs) have attracted increasing attention because of their distinctive features of superior morphological stability and mechanical durability. In recent years, all-PSCs have made rapid progress thanks to...

High-Efficiency Ternary Polymer Solar Cells with a Gradient-Blended Structure Fabricated by Sequential Deposition

“…In addition, a series of tests were examined to evaluate the morphology of gradient-blended active layers with or without ZY-4Cl. First, we utilized atomic force microscopy (AFM) to directly observe the surface morphology and roughness of different films. , The AFM height images are depicted in Figure a–f. The root-mean-square (RMS) roughness values of D18-Cl, Y6, ZY-4Cl, and Y6:ZY-4Cl (Figure S4) were 0.874 7.15, 0.556, and 5.41 nm.…”

Isomeric Monomer Engineering of Regioregular Polymer Acceptors for Efficient All-Polymer Solar Cells

“…Such a molecular design strategy can promote the film-forming property and morphological stability of small molecule acceptors (SMAs) while preserving their unique merits of narrow band gap, strong photon-harvesting ability, and high electron affinity. Benefiting from this polymer acceptor design strategy, the power-conversion efficiency (PCE) of all-PSCs has been elevated to exceed 18%. − Despite these great achievements, most high-performance PSMAs generally constructed from mixed phenyl-fused isomeric terminal groups have region-random polymeric chains, leaving the challenges of batch repeatability and molecular configuration, which intensively impact device performance. − Therefore, designing brominated terminal groups with defined molecular structures is desirable for controlling the regioregularity of polymer chains, thus further advancing the development of all-PSCs.…”

Novel indacene-1,3,5,7-tetraone-based polymerized small molecular acceptors for efficient all-polymer solar cells

“…This is because the last-step synthesis of PSMAs usually requires NFSMA monomers with reactive bromine atoms at the end-capping groups limited by applying the Stille polymerization method. Many electron-accepting groups (malononitrile, thiobarbituric acid, and rhodamine) derived from NFSMAs are not suitable for constructing PSMAs, and the available groups are mainly limited to brominated 2-(3-oxo-2,3-dihydro-1H-inden-1ylidene)malononitrile (IC-Br) and its intricately synthesized derivatives, 29,30 which restricts the further improvement of PSMA performance. In addition, end-capping groups of NFSMA fragments in the polymer mainchain are commonly connected with linker units (such as thiophene derivates) via single bonds (typically, polymer acceptor PYT), 31 resulting in the conformation twist of adjacent groups, which negatively affects the inter/intrachain charge transporting.…”