A Narrow‐Bandgap n‐Type Polymer with an Acceptor–Acceptor Backbone Enabling Efficient All‐Polymer Solar Cells

Advanced Materials, Journal Year: 2020, Volume and Issue: 32(43)

Published: Sept. 21, 2020

Narrow-bandgap polymer semiconductors are essential for advancing the development of organic solar cells. Here, a new narrow-bandgap acceptor L14, featuring an acceptor-acceptor (A-A) type backbone, is synthesized by copolymerizing dibrominated fused-ring electron (FREA) with distannylated bithiophene imide. Combining advantages both FREA and A-A polymer, L14 not only shows narrow bandgap high absorption coefficient, but also low-lying frontier molecular orbital (FMO) levels. Such FMO levels yield improved transfer character, unexpectedly, without sacrificing open-circuit voltage (Voc ), which attributed to small nonradiative recombination loss (Eloss,nr ) 0.22 eV. Benefiting from photocurrent along fill factor Voc , excellent efficiency 14.3% achieved, among highest values all-polymer cells (all-PSCs). The results demonstrate superiority polymers improving all-PSC performance pave way toward developing high-performance acceptors all-PSCs.

Language: Английский

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Simple Non‐Fused Electron Acceptors Leading to Efficient Organic Photovoltaics

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(23), P. 12964 - 12970

Published: April 2, 2021

Abstract Despite the remarkable progress achieved in recent years, organic photovoltaics (OPVs) still need work to approach delicate balance between efficiency, stability, and cost. Herein, two fully non‐fused electron acceptors, PTB4F PTB4Cl, are developed via a two‐step synthesis from single aromatic units. The introduction of two‐dimensional chain halogenated terminals for these acceptors plays synergistic role optimizing their solid stacking orientation, thus promoting an elongated exciton lifetime fast charge‐transfer rate bulk heterojunction blends. As result, upon blending with PBDB‐TF polymer, has enabled single‐junction OPVs power conversion efficiencies 12.76 %, representing highest values among reported unfused so far.

Language: Английский

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Fine-tuning of side-chain orientations on nonfullerene acceptors enables organic solar cells with 17.7% efficiency

Energy & Environmental Science, Journal Year: 2021, Volume and Issue: 14(6), P. 3469 - 3479

Published: Jan. 1, 2021

Regulating side-chain orientations of Y-series NFAs is a promising strategy to achieve favorable morphology, and high charge mobility solar cell performances, which enables high-performance devices with efficiency approaching 18%.

Language: Английский

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A Vinylene‐Linker‐Based Polymer Acceptor Featuring a Coplanar and Rigid Molecular Conformation Enables High‐Performance All‐Polymer Solar Cells with Over 17% Efficiency

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(27)

Published: March 22, 2022

State-of-art Y-series polymer acceptors are typically based on a mono-thiophene linker, which can cause some twisted molecular conformations and thus limit the performance of all-polymer solar cells (all-PSCs). Here, high-performance acceptor vinylene linkers is reported, leads to surprising changes in polymers' conformations, optoelectronic properties, enhanced photovoltaic performance. It found that thiophene or bithiophene (PY-T-γ PY-2T-γ) display significant twisting between end-groups linker units, while vinylene-based (PY-V-γ) exhibits more coplanar rigid conformation. As result, PY-V-γ demonstrates better conjugation tighter interchain stacking, results higher mobility reduced energetic disorder. Furthermore, detailed morphology investigations reveal PY-V-γ-based blend high domain purity fill factor its all-PSCs. With these, efficiency 17.1% achieved all-PSCs, highest reported for binary all-PSCs date. This work vinylene-linker superior unit build with chain conformation, beneficial aggregation efficient

Language: Английский

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Balancing the efficiency, stability, and cost potential for organic solar cells via a new figure of merit

Joule, Journal Year: 2021, Volume and Issue: 5(5), P. 1209 - 1230

Published: April 21, 2021

Language: Английский

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