Organic Solar Cells with Over 19% Efficiency Enabled by a 2D‐Conjugated Non‐Fullerene Acceptor Featuring Favorable Electronic and Aggregation Structures

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(32)

Published: May 27, 2023

The π-expansion of non-fullerene acceptors is a promising method for boosting the organic photovoltaic performance by allowing fine-tuning electronic structures and molecular packing. In this work, highly efficient solar cells (OSCs) are fabricated using 2D strategy to design new acceptors. Compared with quinoxaline-fused cores AQx-16, π-expanded phenazine-fused AQx-18 induce more ordered compact packing between adjacent molecules, affording an optimized morphology rational phase separation in blend film. This facilitates exciton dissociation inhibited charge recombination. Consequently, power conversion efficiency (PCE) 18.2% simultaneously increasing Voc , Jsc fill factor achieved AQx-18-based binary OSCs. Significantly, ternary devices via two-in-one alloy acceptor exhibit superior PCE 19.1%, one highest values ever reported OSCs, along high 0.928 V. These results indicate importance delicate regulation crystalline behaviors achieve performance, aimed at significantly promoting further development

Language: Английский

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A rare case of brominated small molecule acceptors for high-efficiency organic solar cells

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Aug. 5, 2023

Abstract Given that bromine possesses similar properties but extra merits of easily synthesizing and polarizing comparing to homomorphic fluorine chlorine, it is quite surprising very rare high-performance brominated small molecule acceptors have been reported. This may be caused by undesirable film morphologies stemming from relatively larger steric hindrance excessive crystallinity bromides. To maximize the advantages bromides while circumventing weaknesses, three (CH20, CH21 CH22) are constructed with stepwise brominating on central units rather than conventional end groups, thus enhancing intermolecular packing, dielectric constant them without damaging favorable packing through groups. Consequently, PM6:CH22-based binary organic solar cells render highest efficiency 19.06% for acceptors, more excitingly, a record-breaking 15.70% when further thickening active layers ~500 nm. By exhibiting such acceptor, our work highlights great potential achieving delicately brominating.

Language: Английский

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Easy and fast prediction of green solvents for small molecule donor-based organic solar cells through machine learning

Physical Chemistry Chemical Physics, Journal Year: 2023, Volume and Issue: 25(15), P. 10417 - 10426

Published: Jan. 1, 2023

Solubility plays a critical role in many aspects of research (drugs to materials). parameters are very useful for selecting appropriate solvents/non-solvents various applications. In the present study, Hansen solubility predicted using machine learning. More than 40 models tried search best model. Molecular descriptors and fingerprints used as inputs get comparative view. Machine learning trained molecular have shown higher prediction ability model fingerprints. their potential be easy fast compared density functional theory (DFT)/thermodynamic approach. creates "black box" connection properties. Therefore, minimal computational cost is required. With help best-trained model, green solvents selected small molecule donors that organic solar cells. Our introduced framework can select cells an way.

Language: Английский

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High‐Performance Organic Solar Cells Containing Pyrido[2,3‐b]quinoxaline‐Core‐Based Small‐Molecule Acceptors with Optimized Orbit Overlap Lengths and Molecular Packing

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(30)

Published: May 26, 2023

Abstract The central core in A‐DA 1 D‐A‐type small‐molecule acceptor (SMAs) plays an important role determining the efficiency of organic solar cells (OSCs), while principles governing efficient design SMAs remain elusive. Herein, we developed a series with pyrido[2,3‐ b ]quinoxaline (PyQx) as new electron‐deficient unit by combining cascade‐chlorination strategy, namely Py1, Py2, Py3, Py4 and Py5. introduction chlorine atoms reduces intramolecular charge transfer effects but elevates LUMO values. Density functional theory (DFT) reveals that Py2 ortho substituted PyQx Py5 two yield larger dipole moments smaller π⋅⋅⋅π stacking distances, compared other three acceptors. Moreover, shows strongest light absorption capability induced extended orbit overlap lengths more packing structures dimers. These features endow best device performance due to better molecular aggregation behaviors, suitable domain sizes exciton dissociation recombination. This study highlights significance incorporating large moments, small distances dimers into development high‐performance SMAs, providing insight for OSCs.

Language: Английский

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Double Asymmetric Core Optimizes Crystal Packing to Enable Selenophene‐based Acceptor with Over 18 % Efficiency in Binary Organic Solar Cells

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(10)

Published: Jan. 2, 2023

Side-chain tailoring is a promising method to optimize the performance of organic solar cells (OSCs). However, asymmetric alkyl chain-based small molecular acceptors (SMAs) are still difficult afford. Herein, we adopted novel n-nonyl/undecyl substitution strategy and synthesized two A-D1 A'D2 -A double isomeric SMAs with selenophene-based central core for OSCs. Crystallographic analysis indicates that AYT9Se11-Cl forms more compact order intermolecular packing compared AYT11Se9-Cl, which contributed higher electron mobility in neat film. Moreover, PM6 : blend film shows better morphology appropriate phase separation distinct face-on orientation than AYT11Se9-Cl. The OSCs obtain superior PCE 18.12 % AYT11Se9-Cl (17.52 %), best efficiency selenium-incorporated binary BHJ Our findings elucidate chains precisely modulates crystal enhances photovoltaic selenophene-incorporated SMAs.

Language: Английский

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Molecular level understanding of the chalcogen atom effect on chalcogen-based polymers through electrostatic potential, non-covalent interactions, excited state behaviour, and radial distribution function

Polymer Chemistry, Journal Year: 2022, Volume and Issue: 13(42), P. 5993 - 6001

Published: Jan. 1, 2022

Multi-dimensional modelling was used to study the effect of chalcogen atoms on non-covalent interactions, structural and electronic properties polymer materials. Their bulk were also studied at molecular level.

Language: Английский

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Hybrid Cycloalkyl‐Alkyl Chain‐Based Symmetric/Asymmetric Acceptors with Optimized Crystal Packing and Interfacial Exciton Properties for Efficient Organic Solar Cells

Advanced Science, Journal Year: 2023, Volume and Issue: 10(7)

Published: Jan. 2, 2023

Abstract Hybrid cycloalkyl‐alkyl side chains are considered a unique composite side‐chain system for the construction of novel organic semiconductor materials. However, there is lack fundamental understanding variations in single‐crystal structures as well optoelectronic and energetic properties generated by introduction hybrid electron acceptors. Herein, symmetric/asymmetric acceptors (Y‐C10ch A‐C10ch) bearing bilateral unilateral 10‐cyclohexyldecyl designed, synthesized, compared with symmetric acceptor 2,2′‐((2Z,2′Z)‐((12,13‐bis(2‐butyloctyl)‐3,9 bis(ethylhexyl)‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2″,3″′:4′,5′]thieno[2′,3′:4,5] pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐ diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (L8‐BO). The stepwise decreases optical bandgap, deepens energy level, enables molecules to pack closely regular manner. Crystallographic analysis demonstrates that chain endows more planar skeleton enforces compact 3D network packing, resulting an active layer higher domain purity. Moreover, affects donor/acceptor interfacial energetics accelerates exciton dissociation, enabling power conversion efficiency (PCE) >18% 2,2′‐((2Z,2′Z)‐((12,13‐bis(2‐ethylhexyl)‐3,9‐diundecyl12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2″,3″′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (Y6) (PM6):A‐C10ch‐based solar cells (OSCs). Importantly, incorporation Y‐C10ch third component PM6:L8‐BO blend results PCE 19.1%. superior molecular packing behavior highlighted here fabrication high‐performance OSCs.

Language: Английский

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Complete Peripheral Fluorination of the Small‐Molecule Acceptor in Organic Solar Cells Yields Efficiency over 19 %

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(44)

Published: Sept. 14, 2023

Due to the intrinsically flexible molecular skeletons and loose aggregations, organic semiconductors, like small acceptors (SMAs) in solar cells (OSCs), greatly suffer from larger structural/packing disorders weaker intermolecular interactions comparing their inorganic counterparts, further leading hindered exciton diffusion/dissociation charge carrier migration resulting OSCs. To overcome this challenge, complete peripheral fluorination was performed on basis of a two-dimensional (2D) conjugation extended platform CH-series SMAs, rendering an acceptor CH8F with eight fluorine atoms surrounding backbone. Benefitting broad 2D backbone, more importantly, strengthened fluorine-induced secondary interactions, its D18 blends afford much enhanced ordered packings accompanying enlarged dielectric constants, reduced binding energies obvious fibrillary networks CH6F controls. Consequently, D18:CH8F-based OSCs reached excellent efficiency 18.80 %, better than that 17.91 % for CH6F-based ones. More excitingly, by employing D18-Cl possesses highly similar structure as third component, highest 19.28 SMAs-based has been achieved so far. Our work demonstrates dramatical structural multiformity meanwhile, high potential constructing record-breaking through fine-tuning.

Language: Английский

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Over 19.1% efficiency for sequentially spin-coated polymer solar cells by employing ternary strategy

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 471, P. 144711 - 144711

Published: July 13, 2023

Language: Английский

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Step-by-Step Modulation of Crystalline Features and Exciton Kinetics for 19.2% Efficiency Ortho-Xylene Processed Organic Solar Cells

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 16(1)

Published: Nov. 23, 2023

Abstract With plenty of popular and effective ternary organic solar cells (OSCs) construction strategies proposed applied, its power conversion efficiencies (PCEs) have come to a new level over 19% in single-junction devices. However, previous studies are heavily based chloroform (CF) leaving behind substantial knowledge deficiencies understanding the influence solvent choice when introducing third component. Herein, we present case where newly designed asymmetric small molecular acceptor using fluoro-methoxylated end-group modification strategy, named BTP-BO-3FO with enlarged bandgap, brings different morphological evolution performance improvement effect on host system PM6:BTP-eC9, processed by CF ortho-xylene ( o -XY). detailed analyses supported series experiments, best PCE 19.24% for green solvent-processed OSCs is found be fruit finely tuned crystalline ordering general aggregation motif, which furthermore nourishes favorable charge generation recombination behavior. Likewise, can achieved replacing spin-coating blade coating active layer deposition. This work focuses commonly met yet frequently ignored issues building blends demonstrate cutting-edge device performance, hence, will instructive other OSC works future.

Language: Английский

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