Transport Resistance Dominates the Fill Factor Losses in Record Organic Solar Cells

Advanced Energy Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 5, 2025

Abstract Organic photovoltaics (OPV) are a promising solar cell technology well‐suited to mass production using roll‐to‐roll processes. The efficiency of lab‐scale cells has exceeded 20% and considerable attention is currently being given understanding minimizing the remaining loss mechanisms preventing higher efficiencies. While recent improvements partly owed reducing non‐radiative recombination losses at open circuit, low fill factor ( FF ) due significant transport resistance becoming Achilles heel OPV. term refers voltage light intensity‐dependent charge collection in low‐mobility materials. In this perspective, it demonstrated that even highest organic (OSCs) reported to‐date have performance can be attributed lead high losses. A closer look material properties influencing provided. How experimentally characterize quantify described by providing easy follow instructions. Furthermore, causes theory behind detailed. particular, relevant figures merit (FoMs) different viewpoints on integrated. Finally, we outline strategies followed minimize these future cells.

Язык: Английский

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Simple A-D₂-A Nonfullerene Acceptors for Efficient Binary Bulk Heterojunction Organic Solar Cells

ACS Applied Materials & Interfaces, Год журнала: 2025, Номер 17(2), С. 3478 - 3488

Опубликована: Янв. 2, 2025

Two new nonfused ring nonfullerene electron acceptors, NFAs, (dicarbazolyl)bis(2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile) (MDCzM-4H) and -(2-(5,6-fluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile) (MDCzM-4F), thus exhibiting an A-D2-A motif, were synthesized characterized. As thin films, they exhibit the lowest energy absorption signature near 540 nm, extending down to ∼700 nm. This band is due intramolecular charge transfer process from DCz (nonfused dicarbazoyl; DCz) moiety malononitrile-based units (M) based on density functional theory calculations (DFT), which are also corroborated by time-dependent DFT (TDDFT) computations. Both NFAs fluoresce in near-IR region a maximum peaking 750 nm with biphasic lifetimes 75–410 ps time scale. Electrochemical measurements permitted determination of their HOMO (∼−5.7 eV) LUMO (∼−4.0 energies. The bands complementary those commercial copolymer PTB7-Th, was used prepare binary blends for photovoltaic cell performance assessments (ITO/PEDOT:PSS/active layer/PFN-Br/Ag). power conversion efficiencies (PCE) found be 10.17% MDCzM-4H/PTB7-Th (short-circuit current JSC = 15.87 mA cm–2; open-circuit voltage VOC 1.03 V; fill factor FF 0.622) 14.09% MDCzM-4F/PTB7-Th (JSC 20.92 0.965 0.698). use achieving such high performances significant reveals path toward simpler organic photovoltaics.

Язык: Английский

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Thiophene Copolymer Donors Containing Ester-Substituted Thiazole for Organic Solar Cells

ACS Applied Materials & Interfaces, Год журнала: 2025, Номер unknown

Опубликована: Янв. 22, 2025

Organic solar cells have seen significant progress in the past 2 decades with power conversion efficiencies (PCEs) exceeding 20% but mostly based on high-cost photovoltaic materials. Polythiophenes (PTs) without a fused-ring structure are good candidates as low-cost donor materials, deserving more attention for studying. In this work, ester-substituted thiazole (E-Tz) was explored electron-withdrawing unit to design PTs, and further optimization fluorinated/nonfluorinated segment contents via copolymerization strategy simultaneously performed, yielding polymer donors of PTETz-100F, PTETz-80F, PTETz-0F. Suitable temperature-dependent aggregation reasonable phase separation compact molecular packing improved charge transport were achieved PTETz-80F-based system, resulting higher exciton dissociation probability collection probability. Thereby, devices PTETz-80F:L8-BO exhibited best performance PCE 12.69%. addition, synthetic complexity PTETz-XF polymers is 46.05%, which significantly lower than those other representative high-performance donors. This work demonstrates feasibility designing PTs an E-Tz effectiveness material property device optimization.

Язык: Английский

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Recent Advances in Thermo- and Photostabilities of Organic Solar Cells: Material Design and Morphology Control

Polymer science & technology., Год журнала: 2025, Номер unknown

Опубликована: Фев. 27, 2025

Язык: Английский

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Chlorinated Dithiazole‐Based Polymer Donor Enables Over 18% Efficiency for Organic Photovoltaics

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 3, 2025

Abstract Forming an optimal donor:acceptor blend morphology with a low trap state density is highly desired to reach perfect compromise between charge generation and recombination for organic photovoltaics (OPVs), wherein polymer donor plays key role. Here, two wide bandgap donors of PN‐HD PN‐BO are reported, featuring the same low‐cost chlorinated dithiazole as electron‐withdrawing unit but varied alkyl chains on π‐bridged thiophene ring. It found that shorter chain endows merits better miscibility acceptor longer crystallization time, leading more favorable phase separation lower states (tDOS) in resulting active layer. Notably, tDOS 3.51 × 10 15 cm −3 eV −1 PN‐BO:BTP‐eC9‐based device has enabled exceptionally high photocurrent 28.59 mA −2 , thereby efficiency 18.01%, far beyond those (24.64 15.51%) PN‐HD:BTP‐eC9‐based one higher value. The work reveals relationship flexible density, providing new route efficient OPVs.

Язык: Английский

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Efficient non-fused electron acceptor with C-shaped molecular geometry for photovoltaic application

Journal of Materials Chemistry A, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

A novel non-fused acceptor, AC2, with a C-shaped geometry and 3D stacking property, was designed for organic solar cells. AC2 exhibits efficient charge transport reduced energy loss, which broadens the design prospects acceptors.

Язык: Английский

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Green synthesis of simple electron acceptors featuring non-covalent conformational locking and their application in ternary polymer solar cells achieving 18.61% efficiency

Chemical Engineering Journal, Год журнала: 2025, Номер unknown, С. 162659 - 162659

Опубликована: Апрель 1, 2025

Язык: Английский

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π‐Extension Assisted Macrocycle‐Encapsulated Non‐Fused Ring Electron Acceptors with Dual Charge Transporting Pathways for High‐Performance Organic Solar Cells

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 23, 2025

Abstract Achieving compact and ordered charge transfer channels is essential for high‐performance non‐fused ring electron acceptors (NFREAs). Herein, this demonstrated that how the stacking arrangement of molecules with macrocycle encapsulated can be regulated via π‐extension, thus resulting in nearly planar molecular backbones, more dual transport characteristics. In RTT‐TT‐4F , these pronounced aggregation features endow its blend film appropriate phase separation, thereby reducing recombination, balancing carrier mobilities, significantly lowering energy loss OSCs. Consequently, ‐based OSCs achieve remarkable power conversion efficiencies 14.45% 19.76% binary ternary devices, respectively. Our findings provide insights into development NFREAs OSC applications.

Язык: Английский

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Near-Infrared Fully Nonfused Acceptors with Selenophene Central Core and Halogenated End-Groups for Efficient Organic Solar Cells

ACS Applied Polymer Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 31, 2025

Язык: Английский

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Blended solvent for tuning vertical phase separation in layer-by-layer processed thick-film organic solar cells

Science China Chemistry, Год журнала: 2024, Номер unknown

Опубликована: Дек. 25, 2024

Язык: Английский

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