Halogenated Dibenzo[f,h]quinoxaline Units Constructed 2D‐Conjugated Guest Acceptors for 19% Efficiency Organic Solar Cells

Advanced Science, Journal Year: 2024, Volume and Issue: 11(31)

Published: June 17, 2024

Abstract Halogenation of Y‐series small‐molecule acceptors (Y‐SMAs) is identified as an effective strategy to optimize photoelectric properties for achieving improved power‐conversion‐efficiencies (PCEs) in binary organic solar cells (OSCs). However, the effect different halogenation 2D‐structured large π‐fused core guest Y‐SMAs on ternary OSCs has not yet been systematically studied. Herein, four 2D‐conjugated (X‐QTP‐4F, including halogen‐free H‐QTP‐4F, chlorinated Cl‐QTP‐4F, brominated Br‐QTP‐4F, and iodinated I‐QTP‐4F) by attaching halogens into 2D‐conjugation extended dibenzo[ f , h ]quinoxaline are developed. Among these X‐QTP‐4F, Cl‐QTP‐4F a higher absorption coefficient, optimized molecular crystallinity packing, suitable cascade energy levels, complementary with PM6:L8‐BO host. Moreover, among PM6:L8‐BO:X‐QTP‐4F blends, PM6:L8‐BO:Cl‐QTP‐4F obtains more uniform size‐suitable fibrillary network morphology, well vertical phase distribution, thus boosting charge generation, transport, extraction, suppressing loss OSCs. Consequently, PM6:L8‐BO:Cl‐QTP‐4F‐based achieve 19.0% efficiency, which state‐of‐the‐art based superior devices host (17.70%) guests H‐QTP‐4F (18.23%), Br‐QTP‐4F (18.39%), I‐QTP‐4F (17.62%). The work indicates that promising gain efficient

Language: Английский

---

Halogenation Engineering of Solid Additives Enables 19.39% Efficiency and Stable Binary Organic Solar Cells via Manipulating Molecular Stacking and Aggregation of Both Donor and Acceptor Components

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

Published: Oct. 3, 2024

Abstract By selectively interacting with acceptor components, various typed solid additives achieve boosted power conversion efficiency (PCE) in organic solar cells (OSCs). However, due to the efficient active layer being composed of donor and materials, it is difficult obtain desired morphology by manipulating component alone, limiting further improvement PCEs. Herein, two a same backbone thiophene‐benzene‐thiophene (halogen‐free D1‐H) but different halogen substituents (fluorinated D1‐F chlorinated D1‐Cl) are developed probe working mechanism halogenated variation OSCs. Unlike D1‐H continuous charge distributions, D1‐Cl show isolated positive distribution benzene‐core negative thiophene, offering stronger non‐covalent interactions both (PM6) (L8‐BO), especially D1‐Cl. Consequently, D1‐Cl‐treated obtains an optimized phase separation improved molecular packing, boosting PCE 18.59% device stability OSCs, 17.62% for D1‐H‐treated counterparts. Moreover, using D18:L8‐BO D18:BTP‐eC9 as layers, binary OSCs impressive PCEs 19.29% 19.39%, respectively. This work indicates that halogenation engineering can effectively regulate improving elucidates underlying mechanism.

Language: Английский

---

Medium‐Bandgap Acceptors for Efficient Ternary Organic Solar Cells Achieved by End‐Group Engineering

Solar RRL, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

The ternary strategy has been evidenced as one of the most crucial methods to improve photovoltaic performance organic solar cells. However, selection and design third components are decisive factors facilitating progress cells (TOSCs). In this study, focuses concentrated on D18‐Cl:N3 binary host device by developing a weakly electron‐withdrawing end group synthesizing guest acceptor, BTP‐CM, which holds similar backbone N3. structure resemblance ensures good compatibility molecule with N3, improves charge transport reduces recombination. Thereby, D18‐Cl:N3:BTP‐CM‐based TOSC exhibits an improved power conversion efficiency 18.32%, compared 17.13% device. This work provides effective for acceptors, aims introduce new groups obtain molecules complementary absorptions matched energy levels while preserving molecular acceptor.

Language: Английский

---

Sustainable Organic Solar Cells: Materials Review, Molecular Design, and Device Engineering

ACS Applied Engineering Materials, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

Language: Английский

---

Rebuilding Peripheral F, Cl, Br Footprints on Acceptors Enables Binary Organic Photovoltaic Efficiency Exceeding 19.7%

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 8, 2024

Abstract Given homomorphic fluorine (F), chlorine (Cl) and bromine (Br) atoms are featured with gradually enlarged polarizability/atomic radius but decreased electronegativity, the rational screen of halogen species locations on small molecular acceptors (SMAs) is quite essential for acquiring desirable packing to boost efficiency organic solar cells (OSCs). Herein, three isomeric SMAs (CH−F, CH−C CH−B) constructed by delicately rebuilding peripheral F, Cl, Br footprints both central end units. Such a re‐permutation halogens could not only maintain structural symmetry maximum, also acquire extra asymmetric benefits enhanced dipole moment intramolecular charge transfer, etc. Moreover, brominating enhances crystallinity CH−B without introducing undesirable steric hindrance groups, thus rendering better balance between high crystallization domain size control in PM6:CH−B blend. Further benefitting from large dielectric constant, exciton binding energy, optimized great electron transfer integral, affords first class binary OSC 19.78 %, moreover, highest 18.35 % far when increasing active layer thickness ~300 nm. Our successful screening provides valuable insight into further design record‐breaking OSCs.

Language: Английский

---

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

---

Exploring the Effects of Fluorination at the Central Unit of Y6-Type Nonfullerene Acceptors on Photovoltaic Properties: A Computational Investigation

The Journal of Physical Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: May 16, 2025

The strategy of modification central units Y6-type nonfullerene acceptors (NFAs) with halogenation has become popular for designing new photovoltaic materials and shown dramatic effects in improving properties. However, the underlying mechanism how these NFAs influences photoelectric properties remains rather elusive. In this paper, focusing on two reported promising Qx-1 Qx-2, varying degrees ring fusion at units, we designed 4 modeled 10 systematically through fluorination units. Using density functional theory (DFT) time-dependent DFT calculations, explore impact an altered fluorinated location Qx-2 molecular planarity, dipole moment, electrostatic potential (ESP) its fluctuation, exciton binding energy (Eb), singlet-triplet gap, absorption spectrum are obtained combinations traditional hybrid or long-range corrected functionals Pople basis sets. We also developed a numerical method to analyze fluctuation ESP quantitatively because recent reports discussed importance. computed data suggest that newly Qx2-bf Qx2-cf they exhibit enhanced lower Eb (by least 0.002 eV), higher averaged 0.247 kcal/mol) compared Qx-2. find core reduces noticeably, increases standard deviation, raises average except ortho (outside) substitutions. These findings offer valuable physical insights into fluorination, which can serve as guide rational design high-performance QX-based NFAs.

Language: Английский

---

Rebuilding Peripheral F, Cl, Br Footprints on Acceptors Enables Binary Organic Photovoltaic Efficiency Exceeding 19.7%

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 8, 2024

Given homomorphic fluorine (F), chlorine (Cl) and bromine (Br) atoms are featured with gradually enlarged polarizability/atomic radius but decreased electronegativity, the rational screen of halogen species locations on small molecular acceptors (SMAs) is quite essential for acquiring desirable packing to boost efficiency organic solar cells (OSCs). Herein, three isomeric SMAs (CH-F, CH-C CH-B) constructed by delicately rebuilding peripheral F, Cl, Br footprints both central end units. Such a re-permutation halogens could not only maintain structural symmetry maximum, also acquire extra asymmetric benefits enhanced dipole moment intramolecular charge transfer, etc. Moreover, brominating enhances crystallinity CH-B without introducing undesirable steric hindrance groups, thus rendering better balance between high crystallization domain size control in PM6:CH-B blend. Further benefitting from large dielectric constant, exciton binding energy, optimized great electron transfer integral, affords first class binary OSC 19.78 %, moreover, highest 18.35 % far when increasing active layer thickness ~300 nm. Our successful screening provides valuable insight into further design record-breaking OSCs.

Language: Английский

---

Brominated isomerization engineering of 1-chloronaphthalene derived solid additives enables 19.68% efficiency organic solar cells

Materials Science and Engineering R Reports, Journal Year: 2024, Volume and Issue: 162, P. 100879 - 100879

Published: Nov. 18, 2024

Language: Английский

---

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

---