Near‐Infrared Materials: The Turning Point of Organic Photovoltaics

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(10)

Published: Oct. 28, 2021

Abstract Near‐infrared (NIR)‐absorbing organic semiconductors have opened up many exciting opportunities for photovoltaic (OPV) research. For example, new chemistries and synthetical methodologies been developed; especially, the breakthrough Y‐series acceptors, originally invented by our group, specifically Y1, Y3, Y6, contributed immensely to boosting single‐junction solar cell efficiency around 19%; novel device architectures such as tandem transparent photovoltaics realized. The concept of NIR donors/acceptors thus becomes a turning point in OPV field. Here, development NIR‐absorbing materials OPVs is reviewed. According low‐energy absorption window, here, (p‐type (polymers) n‐type (fullerene nonfullerene)) are classified into four categories: 700–800 nm, 800–900 900–1000 greater than 1000 nm. Each subsection covers design, synthesis, utilization various types donor (D) acceptor (A) units. structure–property relationship between kinds D, A units window constructed satisfy requirements different applications. Subsequently, variety applications realized materials, including OPVs, photodetectors, presented. Finally, challenges future next‐generation beyond discussed.

Language: Английский

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18.77 % Efficiency Organic Solar Cells Promoted by Aqueous Solution Processed Cobalt(II) Acetate Hole Transporting Layer

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(41), P. 22554 - 22561

Published: Aug. 21, 2021

Abstract A robust hole transporting layer (HTL), using the cost‐effective Cobalt(II) acetate tetrahydrate (Co(OAc) 2 ⋅4 H O) as precursor, was simply processed from its aqueous solution followed by thermal annealing (TA) and UV‐ozone (UVO) treatments. The TA treatment induced loss of crystal water oxidization Co(OAc) O which increased work function. However, differently realize a high function ideal morphology for charge extraction. resulting problems could be circumvented easily additional UVO treatment, also enhanced conductivity lowered resistance transport. optimal condition found to low temperature (150 °C) simple UVO, where in removed fully HTL surface anchored substantial hydroxy groups. Using PM6 polymer donor L8‐BO electron acceptor, record PCE 18.77 % binary blend OSCs achieved, higher than common PEDOT:PSS‐based solar cell devices (18.02 %).

Language: Английский

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Regioregular Narrow‐Bandgap n‐Type Polymers with High Electron Mobility Enabling Highly Efficient All‐Polymer Solar Cells

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(37)

Published: Aug. 2, 2021

Abstract Narrow‐bandgap n‐type polymers with high electron mobility are urgently demanded for the development of all‐polymer solar cells (all‐PSCs). Here, two regioregular narrow‐bandgap polymer acceptors, L15 and MBTI, electron‐deficient segments synthesized by copolymerizing dibrominated fused‐ring acceptors (FREA) distannylated aromatic imide, respectively. Taking full advantage FREA both show narrow bandgap mobility. Benefiting from more extended absorption, better backbone ordering, higher than those its regiorandom analog, L15‐based all‐PSC yields a power conversion efficiency (PCE) 15.2% when blended donor PM6. More importantly, MBTI incorporating benzothiophene‐core segment shows relatively frontier molecular orbital levels L15, forming cascade‐like energy level alignment Based on this, ternary all‐PSCs designed where is introduced as guest into PM6:L15 host system. Thanks to further optimal blend morphology balanced charge transport, PCE improved up 16.2%, which among highest values all‐PSCs. The results demonstrate that combining an imide construct provides effective approach fabricate highly efficient

Language: Английский

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Process‐Aid Solid Engineering Triggers Delicately Modulation of Y‐Series Non‐Fullerene Acceptor for Efficient Organic Solar Cells

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(20)

Published: March 22, 2022

Volatile solids with symmetric π-backbone are intensively implemented on manipulating the nanomorphology for improving operability and stability of organic solar cells. However, due to isotropic stacking, announced geometry cannot modify microscopic phase separation component distribution collaboratively, which will constrain promotion exciton splitting charge collection efficiency. Inspired by superiorities asymmetric configuration, a novel process-aid solid (PAS) engineering is proposed. By coupling BTP core unit in Y-series molecule, an asymmetric, volatile 1,3-dibromo-5-chlorobenzene can induce anisotropic dipole direction, elevated moment, interlaminar interaction spontaneously. Due synergetic effects favorable desired distribution, PAS-treated devices feature evident improvement splitting, transport, collection, accompanied suppressed trap-assisted recombination. Consequently, impressive fill factor 80.2% maximum power conversion efficiency (PCE) 18.5% device achieved. More strikingly, demonstrate promising thickness-tolerance character, where record PCE 17.0% yielded PAS 300 nm thickness photoactive layer, represents highest thick-film

Language: Английский

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Simple Nonfused Ring Electron Acceptors with 3D Network Packing Structure Boosting the Efficiency of Organic Solar Cells to 15.44%

Advanced Energy Materials, Journal Year: 2021, Volume and Issue: 11(45)

Published: Oct. 17, 2021

Abstract Three nonfused ring electron acceptors (NFREAs; 2Th‐2F, BTh‐Th‐2F, and 2BTh‐2F) with thieno[3,2‐ b ]thiophene bearing two bis(4‐butylphenyl)amino substituents as the core, 3‐octylthiophene or 3‐octylthieno[3,2‐ spacer, 3‐(1,1‐dicyanomethylene)‐5,6‐difluoro‐1‐indanone terminal group are designed synthesized. The molar extinction coefficient of mobility blend films gradually increase increasing π‐conjugation length. Moreover, 2BTh‐2F displays a planar molecular conformation assisted by S···N S···O intramolecular interactions. More importantly, stacking changes from 2D packing for 2Th‐2F analog to 3D network 2BTh‐2F. Due these comprehensive merits, 2BTh‐2F:PBDB‐T‐based organic solar cells give high power conversion efficiency 14.53%. impressively, when D18 is used donor polymer, further enhanced 15.44%, which highest value reported based on NFREAs.

Language: Английский

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Interface Engineering for Highly Efficient Organic Solar Cells

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(16)

Published: March 3, 2023

Organic solar cells (OSCs) have made dramatic advancements during the past decades owing to innovative material design and device structure optimization, with power conversion efficiencies surpassing 19% 20% for single-junction tandem devices, respectively. Interface engineering, by modifying interface properties between different layers OSCs, has become a vital part promote efficiency. It is essential elucidate intrinsic working mechanism of layers, as well related physical chemical processes that manipulate performance long-term stability. In this article, advances in engineering aimed pursue high-performance OSCs are reviewed. The specific functions corresponding principles summarized first. Then, anode layer, cathode layer interconnecting devices discussed separate categories, engineering-related improvements on efficiency stability analyzed. Finally, challenges prospects associated application emphasis large-area, high-performance, low-cost manufacturing.

Language: Английский

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Research Progress of Intramolecular π‐Stacked Small Molecules for Device Applications

Advanced Materials, Journal Year: 2021, Volume and Issue: 34(22)

Published: Oct. 1, 2021

Abstract Organic semiconductors can be designed and constructed in π‐stacked structures instead of the conventional π‐conjugated structures. Through‐space interaction (TSI) occurs optoelectronic materials. Thus, unlike electronic coupling along conjugated chain, functional groups stack closely to facilitate spatial electron communication. Using motifs, chemists materials scientists find new ways for constructing with aggregation‐induced emission (AIE), thermally activated delayed fluorescence (TADF), circularly polarized luminescence (CPL), room‐temperature phosphorescence (RTP), as well enhanced molecular conductance. devices based on molecules have exhibited very promising performance, some them exceeding analogues. Recently, reports various organic grown rapidly, prompting this review. Representative scaffolds newly developed systems could stimulate more attention through‐space charge transfer well‐known through‐bond transfer. Finally, opportunities challenges utilizing improving particular are discussed. The previous achievements upcoming prospects may provide insights into theory, materials, field semiconductors.

Language: Английский

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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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Alkyl‐Chain Branching of Non‐Fullerene Acceptors Flanking Conjugated Side Groups toward Highly Efficient Organic Solar Cells

Advanced Energy Materials, Journal Year: 2021, Volume and Issue: 11(47)

Published: Oct. 29, 2021

Abstract Side‐chain modifications of non‐fullerene acceptors (NFAs) are essential for harvesting their full potential in organic solar cells (OSC). Here, an effective alkyl‐chain‐branching approach the Y‐series NFAs flanking meta‐substituted phenyl side groups at outer positions is demonstrated. Compared to BTP‐4F‐PC6 with linear m ‐hexylphenyl chains, two new named BTP‐4F‐P2EH and BTP‐4F‐P3EH developed bulkier alkyl chains branched β γ positions, respectively. These result altered molecular packing afford higher open‐circuit voltage devices. Despite blue‐shifted absorption branched‐chain NFAs, blends PBDB‐T‐2F enable improved short‐circuit current density corresponding devices owing more suitable phase separation better exciton dissociation. Consequently, OSCs based on yield enhanced device performance 18.22% 17.57%, respectively, outperforming BTP‐4F‐PC6‐based ones (17.22%). results highlight that side‐chain branching design has great optimizing properties promoting photovoltaic performance.

Language: Английский

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Auxiliary sequential deposition enables 19%-efficiency organic solar cells processed from halogen-free solvents

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

Published: Oct. 31, 2023

High-efficiency organic solar cells are often achieved using toxic halogenated solvents and additives that constrained in industry. Therefore, it is important to develop materials or processing methods enabled highly efficient processed by halogen free solvents. In this paper, we report an innovative method named auxiliary sequential deposition enables 19%-efficiency Our different from the conventional blend casting involves additional of dithieno[3,2-b:2',3'-d]thiophene between depositions donor (D18-Cl) acceptor (L8-BO) layers. The dramatic performance enhancement 15% over 18% compared methods. Furthermore, incorporating a branched-chain-engineered called L8-BO-X, device can be boosted 19% due increased intermolecular packing, representing top-tier values for green-solvent cells. Comprehensive morphological time-resolved characterizations reveal superior morphology through promotes charge generation while simultaneously suppressing recombination. This research underscores potential fabricating environmentally friendly

Language: Английский

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