Efficient and Stable Organic Solar Cells Achieved by Synergistic Optimization of Extended End‐Capped Groups and Fluorinated Quinoxaline Central Cores in Nonfullerene Acceptors

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 14, 2024

Abstract Molecular stacking behavior exerts a significant influence on the blend film morphology of organic solar cells (OSCs), further affecting device performance and stability. Modulation molecular structure, such as central unit end‐group, can profoundly impact this process. Herein, four quinoxaline (Qx)‐fused‐core‐based non‐fullerene acceptors (NFAs), Qx‐N4F Qx‐ o/m/p ‐N4F are synthesized combining π‐extended end‐groups optimized units. The isomeric fluorinated units lead to changes in local dipole moments electrostatic potential distribution, which influences pattern photoelectronic properties NFAs. Consequently, binary ternary devices based PM6:Qx‐ p achieve superior power conversion efficiencies (PCE) up 18.75% 19.48%, respectively. Grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) characterization reveals ‐N4F's stronger crystallinity, aggregation, donor–acceptor interactions, separately enhance short‐circuit current density ( J SC ) fill factor (FF) through higher phase purity tighter maintaining more interfaces. Furthermore, ‐N4F‐based demonstrate exceptional thermal stability, retaining 93.2% initial PCE value after 3000 h heating due best morphological stability with most stable structure. These results underscore significance synergistic optimization NFAs conjugation expansion halogenation substitution for obtaining efficient OSCs.

Language: Английский

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Progress in the Stability of Small Molecule Acceptor‐Based Organic Solar Cells

Advanced Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 5, 2024

Abstract Significant advancements in power conversion efficiency have been achieved organic solar cells with small molecule acceptors. However, stability remains a primary challenge, impeding their widespread adoption renewable energy applications. This review summarizes the degradation of different layers within device structure under varying conditions, including light, heat, moisture, and oxygen. For photoactive layers, chemical pathways polymer donors acceptors are examined detail, alongside morphological bulk heterojunction structure, which plays crucial role performance. The mechanisms commonly used anode cathode interlayers electrodes addressed, as these significantly influence overall stability. Mitigation methods for identified provided each section to offer practical insights improving longevity. Finally, an outlook presents remaining challenges achieving long‐term stability, emphasizing research directions that require further investigation enhance reliability performance real‐world

Language: Английский

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Delicate Regulation of Central Substituents Boosts Organic Photovoltaic Performance of Dimeric Acceptors

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

Published: Sept. 3, 2024

Abstract Dimeric acceptors are expected to satisfy both excellent power conversion efficiency (PCE) and operational stability of organic solar cells (OSCs). However, comparing highly planar symmetrical monomer‐like acceptors, the quite different steric/spatial configurations dimeric affect device outcomes greatly. Herein, on basis same molecular platform that constructed by bridging central units two acceptor, diverse substituents (─OCH 3 for D1, ─CH D2, ─CF D3) grafted regulate three dimensions (3D) geometries delicately. A systematic investigation reveals substituent‐dependent variation energy level, absorption, packing behavior. Consequently, D2 characteristic more favorable configuration, affords a superior film morphology charge transfer/transport dynamics in resulting OSCs, thus yielding an PCE 17.50% along with good long‐term stability. This work manifests crucially important role constructing high‐performance acceptors.

Language: Английский

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Regulation of Side‐Chain Symmetry for Delaying Triplet Formation and Suppressing Non‐Radiative Loss in Organic Solar Cells

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 27, 2024

Abstract The structural revolutions of non‐fullerene acceptors (NFAs) have driven continuous efficiency breakthroughs in organic solar cells (OSCs). Rational regulation NFA structures toward efficient exciton dissociation and mitigated non‐radiative recombination is pivotal for OSCs. incorporation asymmetric side chains on NFAs can often achieve these goals by inducing a desirable aggregate state. However, it lacks the studies to directly correlate side‐chain symmetry with delocalization triplet dynamics Herein, influence properties systematically investigated exciton/charge based two developed biaxial‐conjugated varied symmetry. symmetric having diverse molecular packing orientations form multiple charge transfer channels its blend polymer donor, which cannot be found that comprising ones. Moreover, slower rate lower ratio spin‐triplet state are formed NFA, resulting much voltage loss corresponding This study reveals distinct advantages both over those ones, paving way developing high‐performance OSCs using easier‐to‐prepare, low‐cost materials.

Language: Английский

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Polyfluoride Acceptor with Limited Molecular Diffusion Enables Efficient and Stable Ternary Organic Solar Cells

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(35), P. 46332 - 46340

Published: Aug. 23, 2024

Due to the slow diffusion of photovoltaic molecules, in particular, small-molecule acceptors (SMAs), under light and heating, morphology active layer organic solar cells (OSCs) prefers deviate from favorably metastable status, leading challenge stability during long-term operation. Employing materials with a high glass transition temperature (Tg) as third component suppress molecular is an efficient method achieve balance efficiency OSCs. Herein, dimerized acceptor denoted F6D synthesized by introducing polyfluoride moiety linker enhance Tg. Benefitting rational design, not only exhibits higher Tg, complementary absorption, cascade energy levels host polymer donor PM6 SMA Y6 but also has excellent miscibility multiple intermolecular interactions Y6. As result, champion power conversion 17.52% achieved optimal PM6:Y6:F6D-based device. More importantly, ternary device superior continuous heating lighting compared binary

Language: Английский

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A Steric Camphane-Functionalized Fused-Ring Electron Acceptor for Efficient Ternary Non-Fullerene Organic Solar Cells

ACS Applied Energy Materials, Journal Year: 2024, Volume and Issue: 7(22), P. 10662 - 10669

Published: Nov. 9, 2024

Functionalization of Y-type non-fullerene acceptors (Y-NFAs) with bulky units at the alkyl chains, terminal IC ends, or central cores has been an efficient route to boosting efficiency NFA-based organic solar cells (OSCs). Single-crystal structure analysis a powerful tool provide detailed information, such as bending conjugated backbone and packing formats molecules in solid, which can supply valuable insight into performance relation direct further molecular design new NFAs. However, growth high-quality single crystals NFAs groups is often challenging. Herein, we designed synthesized NFA, Norb-Y, decorated steric camphane unit on core through fused quinoxaline bridge. Norb-Y was successfully characterized by single-crystal analysis, revealing well-fined atomic intermolecular stacking format. Notably, displays better coplanarity small dihedral angle 18° between two groups. Moreover, three kinds π–π modes corresponding J-aggregation were identified, including end-to-end, arm-to-arm, tail-to-tail modes, all contributed segment from thiophene end. Meanwhile, H-aggregation associating suppressed units, drives assembly C–H···F H bonds instead. This kind significance for reducing voltage loss increasing OSCs' open circuit voltage, finally verified PM6:BTP-eC9:Norb-Y- D18:N3:Norb-Y-based ternary OSCs.

Language: Английский

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Siloxane as Humidity‐Resistant and Stabilizing Additive for Ambient‐Processed Organic Solar Cells

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 8, 2024

Abstract High‐performing organic solar cells (OSCs) being processed in ambient conditions and possessing long‐term stability are desired toward commercialization. Here, resultantly bifunctional additive is proposed for active layer, which can greatly enhance humidity endurance during the air‐processing of layer device meantime. Intriguingly, with 1% octamethyltrisiloxane (3Si) as additive, casting PM6:L8‐BO even 90% relative (RH) air could show comparable efficiency to that N 2 condition. Furthermore, 3Si‐processed layers also display remarkably enhanced thermal light stabilities conventional OSCs. After aging at 85 °C 1000 h simulated UV band 100 mW cm −2 55°C h, binary OSCs maintain 91.6% 86.1% initial efficiency, leading final averaged efficiencies 16.17% 15.42%, respectively. The results represent most stable based on strategy. universality siloxane a humidity‐resistant stabilizing agent confirmed other systems, paving way broader application additive.

Language: Английский

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A Low‐Cost 3D Spirobifluorene‐Based Acceptor for High‐Performance Ternary Organic Solar Cells

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 2, 2024

Abstract The advantages of 3D materials as guest components ternary organic solar cells (TOSCs) are being realized, showing great potential in improving device performance. However, the correlation between their distinctive structure and performance remains largely unexplored. Herein, a acceptor named SF‐HR is cost‐effectively synthesized utilizing twisted spirofluorene core. shows an edge‐on oriented packing but not disordered aggregation other molecules. When introduced into D18:Y6 binary system, can induce more predominant face‐on finer domain size blend, which facilitates exciton dissociation multi‐direction charge transport. Besides, exhibits complementary absorption cascaded energy levels with D18 Y6, contributing to improvement short‐circuit current density ( J sc ) open‐circuit voltage V oc ), respectively. Accordingly, optimized achieves higher 0.893 V, 27.13 mA cm −2 , fill factor (FF) 77.8%, respectively, than that host device, yielding excellent efficiency 18.85%. This success demonstrates utilization crystalline material component represents promising strategy for achieving state‐of‐the‐art OSCs, conducive understanding relationship from new perspective.

Language: Английский

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Quinoxaline based A-A Type Polymer Donors for Non-Fullerene Polymer Solar Cells

Synthetic Metals, Journal Year: 2024, Volume and Issue: unknown, P. 117773 - 117773

Published: Oct. 1, 2024

Language: Английский

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