Developing Efficient Benzene Additives for 19.43% Efficiency of Organic Solar Cells by Crossbreeding Effect of Fluorination and Bromination

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(8)

Published: Nov. 12, 2023

Abstract Employing volatile solid additives have emerged as a promising method to optimize the morphology and improve performance of organic solar cells (OSCs). However, principles governing efficient design remain elusive. Herein, programmed fluorination and/or bromination on benzene core develop for OSCs is reported. The endow five halogen derivatives, 1,3,5‐trifluorobenzene, hexafluorobenzene, 1,3,5‐tribromo‐2,4,6‐trifluorobenzene (TFTB), 1,3,5‐tribromobenzene, hexabromobenzene, with different melting boiling points, volatility, well interactions host blend. Studies indicate that extremely high low volatility are almost powerless even detrimental evolution. Among them, combination fluorine bromine atoms TFTB not only enables more appropriate m.p./b.p. but also exerts stronger molecular blend, giving rise higher ordered packing favorable morphology. Importantly, exhibits good universality performances power conversion efficiencies (PCEs; over 18%) in group binary blend systems, an impressive PCE 19.43% ternary PBTz‐F:PM6:L8‐BO system.

Language: Английский

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3D Crystal Framework Regulation Enables Se‐Functionalized Small Molecule Acceptors Achieve Over 19% Efficiency

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(19)

Published: March 10, 2024

Abstract Se‐functionalized small molecule acceptors (SMAs) exhibit unique advantages in constructing materials with near‐infrared absorption, but their photovoltaic performance lags behind that of S‐containing analogs organic solar cells (OSCs). Herein, two new Se‐containing SMAs, namely Se‐EH and Se‐EHp, are designed synthesized by regulating bifurcation site outer alkyl chain, which enables Se‐EHp to form different 3D crystal frameworks from CH1007. displays tighter π–π stacking denser packing framework smaller‐sized pore structure induced larger steric hindrance effect chain branched at 2‐position, a higher dielectric constant PM6:Se‐EH active layer can be obtained. OSCs based on achieved very high PCEs 18.58% binary 19.03% ternary devices FF approaching 80% for SMAs. A more significant adjusts the molecular crystallization favorable nanofiber interpenetrating network an appropriate domain size reduce rate sub‐ns recombination promote balanced transport carriers. This work provides references further design development highly efficient

Language: Английский

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Insights Into Pre‐aggregation Control of Y‐series Non‐fullerene Acceptors in Liquid State for Highly Efficient Binary Organic Solar Cells

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(30)

Published: June 5, 2024

Abstract Leveraging breakthroughs in Y‐series nonfullerene acceptors (NFAs), organic solar cells (OSCs) have achieved impressive power conversion efficiencies (PCEs) exceeding 19%. However, progress advancing OSCs has decelerated due to constraints realizing the full potential of NFAs. Herein, a simple yet effective solid additive‐induced preaggregation control method employing 2‐chloro‐5‐iodopyridine (PDCI) is reported unlock Specifically, PDCI interacts predominantly with NFAs enabling enhanced and ordered phase‐aggregation solution. This leads notable improvement redshifted absorption acceptor phase during film formation, along improved crystallinity. Moreover, PDCI‐induced solution enables molecule packing film‐formation process through delicate intermediate states transition. Consequently, preaggregated significantly improves PCE PM6:Y6 from 16.12% 18.12%, among best values for OSCs. Importantly, this approach universally applicable other NFA‐based OSCs, achieving champion 19.02% PM6:BTP‐eC9 system. Thus, strategy further unlocks NFAs, offering promising avenue enhancing photovoltaic performance

Language: Английский

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Volatile Solid‐Assisted Molecular Assembly Enables Eco‐Friendly Processed Organic Photovoltaic Cells with High Efficiency and Photostability

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(17)

Published: Jan. 4, 2024

Achieving environmentally friendly solvent-processed high-performance organic photovoltaic cells (OPVs) is a crucial step toward their commercialization. Currently, OPVs with competitive efficiencies rely heavily on harmful halogenated solvent additives. Herein, the green and low-cost 9-fluorenone (9-FL) employed as solid additive. By using o-xylene/9-FL system, PM6:BTP-eC9-based devices deliver power-conversion of 18.6% 17.9% via spin-coating blade-coating respectively, outperforming all PM6:Y-series binary solvents. It found that addition 9-FL can regulate molecular assembly both PM6 BTP-eC9 in film-formation (molecule-level mixing) post-annealing (thermal-assisted reorganization additive volatilization) stages, so to optimize blend morphology. As result, charge transport ability donor acceptor phases are simultaneously enhanced, trap-assisted recombination reduced, which contributes higher short-circuit current density fill factor. Moreover, generation photo-induced traps significantly suppressed, resulting improved stability under illumination. further demonstrated excellent universality various photoactive systems, making it promising strategy advance development eco-friendly OPVs.

Language: Английский

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Triadic Halobenzene Processing Additive Combined Advantages of Both Solvent and Solid Types for Efficient and Stable Organic Solar Cells

Small, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 3, 2024

Solvent additives with a high boiling point (BP) and low vapor pressure (VP) have formed key handle for improving the performance of organic solar cells (OSCs). However, it is not always clear whether they remain in active-layer film after deposition, which can negatively affect reproducibility stability OSCs. In this study, an easily removable solvent additive (4-chloro-2-fluoroiodobenzene (CFIB)) BP VP introduced, behaving like volatile solid that be completely removed during device fabrication process. In-depth studies CFIB addition into D18-Cl donor N3 acceptor validate its dominant non-covalent intermolecular interactions through effective electrostatic interactions. Such phenomena improve charge dynamics kinetics by optimizing morphology, leading to enhanced D18-Cl:N3-based devices power conversion efficiency 18.54%. The CFIB-treated exhibits exceptional thermal (T80 lifetime = 120 h) at 85 °C compared CFIB-free device, because morphological robustness evolving no residual film. features combination advantages (easy application) (high volatility) additives, demonstrating great potential use commercial mass production

Language: Английский

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