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Balancing and improving the open‐circuit voltage (Voc) and short‐circuit current density (Jsc) synergistically has always been the critical point for organic photovoltaics (OPVs) to achieve high efficiencies. Here, this work adopts a ternary strategy to regulate the trade‐off between Voc and Jsc by combining the symmetric‐asymmetric non‐fullerene acceptors that differ at terminals and alkyl side chains to build the ternary OPV (TOPV). It is noticed that the reduced energy disorder and the enhanced luminescence efficiency of TOPV enable a mitigated energy loss and a higher Voc. Meanwhile, the third component, which is distributed at the host donor–acceptor interface, acts as the charge transport channel. The prolonged exciton lifetime, the boosted charge mobility, and the depressed charge recombination promote the TOPV to obtain an improved Jsc. Finally, with synergistically improved Voc and Jsc, the TOPV delivers an optimal efficiency of 19.26% (certified as 19.12%), representing one of the highest values reported so far. [ABSTRACT FROM AUTHOR]

Ternary strategy, adding an additional donor (D) or acceptor (A) into conventional binary D:A blend, has shown great potential in improving photovoltaic performances of organic photovoltaics (OPVs) for practical applications. Herein, this review is presented on how efficient ternary OPVs are realized from the aspects of morphology, energy loss, and working mechanism. As to morphology, the role of third component on the formation of preferred alloy‐like‐phase and vertical‐phase, which are driven by the miscibility tuning, is discussed. For energy loss, the effect of the third component on the luminescence enhancement and energetic disordering suppression, which lead to favorable increase of voltage, is presented. Regarding working mechanism, dilution effect and relationships between two acceptors or donor/acceptor, which explain the observed device parameters variations, are analyzed. Finally, some future directions concerning ternary OPVs are pointed out. Therefore, this review can provide a comprehensive understanding of working principles and effective routes for high‐efficiency ternary systems, advancing the commercialization of OPVs. [ABSTRACT FROM AUTHOR]

Abstract: Herein, efficient organic solar cells (OSCs) are realized with the ternary blend of a medium band gap donor (poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione)] (PBDB‐T)) with a low band gap acceptor (2,2′‐((2Z,2′Z)‐(((2,5‐difluoro‐1,4‐phenylene)bis(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene‐6,2‐diyl))bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (HF‐PCIC)) and a near‐infrared acceptor (2,2′‐((2Z,2′Z)‐(((4,4,9,9‐tetrakis(4‐hexylphenyl)‐4,9‐dihydro‐s‐indaceno[1,2‐b:5,6‐b′]dithiophene‐2,7‐diyl)bis(4‐((2‐ethylhexyl)oxy)thiophene‐5,2‐diyl))bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile (IEICO‐4F)). It is shown that the introduction of IEICO‐4F third component into PBDB‐T:HF‐PCIC blend increases the short‐circuit current density (J sc) of the ternary OSC to 23.46 mA cm−2, with a 44% increment over those of binary devices. The significant current improvement originates from the broadened absorption range and the active layer morphology optimization through the introduction of IEICO‐4F component. Furthermore, the energy loss of the ternary cells (0.59 eV) is much decreased over that of the binary cells (0.80 eV) due to the reduction of both radiative recombination from the absorption below the band gap and nonradiative recombination upon the addition of IEICO‐4F. Therefore, the power conversion efficiency increases dramatically from 8.82% for the binary cells to 11.20% for the ternary cells. This work provides good examples for simultaneously achieving both significant current enhancement and energy loss mitigation in OSCs, which would lead to the further construction of highly efficient ternary OSCs. [ABSTRACT FROM AUTHOR]

In this Letter, a new AlQ 3 derivative is designed and synthesized through introducing 2-ethylhexyl cyanoacrylate at C-4 of the quinoline ring. The obtained Al(4CAQ) 3 shows excellent solubility (>50 mg/ml) in common solvents. Furthermore, the LUMO energy level of Al(4CAQ) 3 is greatly lowered to −3.70 eV, which matches those of donors used in organic solar cells (OSCs). Together with its octahedral molecular geometry and good UV–visible absorptions, Al(4CAQ) 3 would be a promising solution-processed electron acceptor for OSCs. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) show the potential to harness solar energy at a lower cost and in a greener way with the merits of mechanical flexibility and potential low‐cost upscaling production with solution processing. Meanwhile, the common use of toxic halogenated solvents causes pollution to the natural environment, and thus, needs to be avoided. Following the authors' previous work on the design of top‐illuminated ultrathin Ag‐based device structure highlighting most merits of OSC, herein non‐halogen solvent and additive processing OSCs are presented, which exhibit high power conversion efficiency (PCE) of 17.64%, close to the best PCE with the commonly used halogen solvent. Interestingly, it is observed that the additive and the multicomponent strategy (blending third component BTP‐S2 into PM6:L8‐BO binary blend) synergistically affect the optimal morphology and device performance. Finally, OSC devices featuring green solvent processing, indium tin oxide‐free, flexibility, and upscaling merits are fabricated and exhibit the best PCE of 13.76% with high mechanical robustness and good stability against heat or light illumination. This work provides a prospective potential for manufacturing the OSC toward practical applications. [ABSTRACT FROM AUTHOR]

The simultaneous achievement of a low energy loss and high external quantum efficiency (EQE) response is the prerequisite for high power conversion efficiencies of organic solar cells (OSCs). Herein, this issue is examined through the design of two novel near‐infrared (NIR) nonfullerene acceptors (X‐PCIC and X1‐PCIC) with an absorption extending to 900 nm, which is realized by using benzobis(thiazole) unit as the core. This study reveals that benzobis(thiazole) unit with the quinoid‐resonance effect and electron‐withdrawing property is a good building block in extending absorption and maintaining suitable energy levels. Single crystal cultivation proves the function of S···N noncovalent interaction in locking molecular geometry. Besides, through adopting two different terminals (fluorinated terminal for X‐PCIC and thiophene‐fused terminal for X1‐PCIC), it is found that an increase in the J‐aggregation strength has a significant positive effect on the EQE response of the devices through the formation of more suitable domain sizes and crystallinity in the films, while the energy loss remains low (≈0.53 eV) and unaffected. Thus, a high efficiency of 11.50% is presented for OSC based on the X‐PCIC with stronger J‐aggregation strength, better than that (10.17%) based on the X1‐PCIC with weaker J‐aggregation strength. This work clearly demonstrates the application of benzobis(thiazole) unit in efficient small molecule acceptors and the importance of J‐aggregation modulation for the simultaneous achievement of low energy loss and high EQE response. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) hold immense potential as renewable energy sources, but the performance‐stability conundrum remains a major obstacle on the road to OSC commercialization. To address this, in this study, molecular packing behaviors of representative state‐of‐the‐art Y‐series non‐fullerene acceptors (NFAs) are studied, focusing on their terminal group symmetries. Utilizing grazing‐incidence wide‐angle X‐ray scattering, the distinct crystalline packing structure of these NFAs is revealed. Remarkably, NFAs with asymmetric terminals exhibited excellent additive insensitivity and thermal stability for their crystalline structure, unlike their symmetric counterparts. Molecular dynamics simulations confirmed the stable and robust crystalline feature of asymmetric NFAs and attributed to their large molecular dipole moments. These findings showed the great potential of asymmetric NFAs in fabricating efficient and intrinsically stable additive‐free OSC devices for real applications. [ABSTRACT FROM AUTHOR]

• OPVs based on a quaternary blend with a vertical phase distribution are fabricated. • A PCE of 19.19% (certified as 19.18%) is achieved for chloroform-processed device. • A PCE of 19.04% is achieved for toluene-processed quaternary device. • The upscaled large-area module (72.25 cm2) presents a PCE of 12.78%. Building a vertical phase distribution morphology with a simple method is the critical key for high-efficiency organic photovoltaics (OPVs) and their industrial application. Here, OPVs based on a quaternary system with one donor PM6 and three acceptors (L8-BO, BTP-S8, and BTP-S2) were fabricated. The L8-BO-based blend was demonstrated to show unique vertical phase distribution (acceptors enriched on the top surface), leading to an exquisite morphology and superior carrier behaviors, thus power conversion efficiencies (PCEs) of 19.19% (certified as 19.18%) and 19.04% were achieved for chloroform-processed and toluene-processed devices, respectively. The high efficiency obtained from greener solvent is encouraging for commercialization of OPVs. Notably, the device processed with toluene without any additives shows a PCE of 17.28% with good stability, and the upscaled large-area module with a total area of 72.25 cm2 processed in air presents an outstanding PCE of 12.78%. This work provides valuable insights into the fabrication of greener solvent and large-area module OPVs. [ABSTRACT FROM AUTHOR]

Abstract Non-fullerene organic solar cells (OSCs) have attracted great attention due to their advantages such as tunable energy levels, reduced energy loss, strong light absorption. Here, three small molecules with polar functional groups were utilized to modify the surface of zinc oxide (ZnO) electron transport layer through self-assembled monolayers (SAMs) formation. Inverted non-fullerene OSCs with PBDB-T:ITIC blend as active layer based on the ZnO with SAMs modification showed enhanced device performance (10.90%) compared to that without SAM treatment (10.03%). The ultraviolet photoelectron spectroscopy results revealed that the SAMs could lower the surface work function of ZnO, allowing for better electron extraction. The analysis results of J-V characteristics under different light illumination intensities suggested more efficient charge dissociation and weaker trap-assisted bimolecular recombination in the devices with SAMs modification. Our work provides an effective approach to modify the ZnO surface for efficient non-fullerene OSCs. Graphical abstract The ZnO was modified by three self-assembled small molecules and used as electron transport layer to fabricate inverted non-fullerene organic solar cells (OSCs). The devices based on the modified ZnO showed more efficient charge dissociation and weaker trap-assisted bimolecular recombination. As a result, the power conversion efficiency of OSCs based on PBDB-T:ITIC was improved from 10.03% to 10.90%. Image 1 Highlights • The work function of ZnO electron transport layer (ETL) was adjusted via self-assembled monolayer (SAM) modification. • Inverted non-fullerene organic solar cells (OSCs) with ZnO ETL were fabricated. • OSCs with SAM modification has more efficient charge dissociation and weaker trap-assisted bimolecular recombination. • The OSCs based on the modified ZnO showed enhanced performance from 10.03% to 10.90%. [ABSTRACT FROM AUTHOR]

Simultaneously achieving improvements in power conversion efficiency (PCE) and stability is the main task of the current development stage of organic solar cells (OSCs). This work reports a symmetry–asymmetry dual‐acceptor (SADA) strategy to construct ternary devices, which is found to be feasible for increasing both the PCE and the operational lifetime of OSCs. In this contribution, the symmetric acceptor L8‐BO and the asymmetric acceptor BTP‐S9 are blended in equal proportions with polymer donor PM6 for the consideration of absorption spectrum complementarity and cascade energetic alignment. In addition, the features of crystallinity and miscibility of the dual‐acceptor deliver optimized morphology lead to a high PCE of 18.84%. In addition, the asymmetric acceptor BTP‐S9 with a larger dipole moment shows tighter molecular stacking and longer crystal correlation length, which favor intrinsic molecular photostability, and further consolidate the operational lifetime of OSCs when coordinated with L8‐BO. This work demonstrates the efficacy of the SADA strategy for constructing efficient and stable OSCs. [ABSTRACT FROM AUTHOR]

Large energy loss is one of the main limiting factors for power conversion efficiencies (PCEs) of organic solar cells (OSCs). To this effect, the chemical modifications of the famous Y‐series nonfullerene acceptor (NFA) BTP‐4Cl‐BO with a new end group, TPC‐Cl, whose π‐conjugation is extended through the fusing of 3‐(dicyanomethylene)indanone (IC) group with a chlorinated thiophene ring, to synthesize two novel NFAs, BTP‐T‐2Cl and BTP‐T‐3Cl are performed. For BTP‐T‐2Cl with two TPC‐Cl groups, the resulting OSC exhibits a modest PCE of 14.89% but an extraordinary low energy loss of 0.49 eV, because its superior electroluminescence quantum efficiency of 0.0606% mitigates significantly the nonradiative loss (0.191 eV). For BTP‐T‐3Cl with one TPC‐Cl group, the corresponding device shows a higher PCE of 17.61% accompanied by a slightly bigger energy loss of 0.51 eV, which can be ascribed to the optimized morphology and/or efficient charge generation. Furthermore, the ternary OSC adopting two NFAs of BTP‐T‐3Cl and BTP‐4Cl‐BO achieves an impressive PCE of 18.21% (certified value of 17.9%), which is among the highest values for OSCs to date. The above results demonstrate that expanding end groups of NFAs with electron‐donating rings is an effective strategy to realize lower energy losses for OSCs. [ABSTRACT FROM AUTHOR]

Membrane blebbing during the apoptotic execution phase results from caspase-mediated cleavage and activation of ROCK I. Here, we show that ROCK activity, myosin light chain (MIC) phosphorylation, MLC ATPase activity, and an intact actin cytoskeleton, but not microtubular cytoskeleton, are required for disruption of nuclear integrity during apoptosis. Inhibition of ROCK or MIC ATPase activity, which protect apoptotic nuclear integrity, does not affect caspase-mediated degradation of nuclear proteins such as lamins A, 81, or C. The conditional activation of ROCK I was sufficient to tear apart nuclei in lamin A/C null fibroblasts, but not in wild-type fibroblasts. Thus, apoptotic nuclear disintegration requires actin-myosin contractile force and lam in proleolysis, making apoptosis analogous to, but distinct from, mitosis where nuclear disintegration results from microtubule-based forces and from lamin phosphorylation and depolymerization. [ABSTRACT FROM AUTHOR]

Constructing unfused-core non-fullerene acceptors (NFAs) via intramolecular noncovalent interactions has been recognized as an effective route to obtain high-efficiency and low-cost concurrently for organic solar cells (OSCs). Herein, we report two new unfused-core NFAs, NCIC and NOCIC, with pyrazine and pyridazine as the cores, respectively. In contrast to traditional unfused-cores with fluorine or alkyloxy substituents, the nitrogen-containing six-membered heterocycle cores of NCIC and NOCIC have no substituents, which simplifies further synthetic steps of unfused-core NFAs. In the meantime, utilizing N⋯S and/or N⋯H interactions between the cores and adjacent cyclopentadithiophene (CPDT) units, NCIC and NOCIC own good π-conjugated backbone planarity, consequently, show intense absorptions from 550 nm to 800 nm. Moreover, the electronegativity of aromatic N atoms in the cores pulls down the highest occupied molecular orbital (HOMO) energy levels of the two NFAs, with -5.65 eV and -5.59 eV for NCIC and NOCIC, respectively, which is favorable for them to pair with the polymer donor with a deep HOMO level, PM6, to fabricate bulk-heterojunction (BHJ) OSCs. Finally, the PM6:NCIC based devices yield the best power conversion efficiency (PCE) of 10.32%, while those based on PM6:NOCIC blends provide a maximum PCE of 9.89%. This work demonstrates that the nitrogen-containing six-membered heterocycle is a kind of potential building block for high-performance and easy-synthesis unfused-core NFAs. [Display omitted] • Two non-fullerene acceptors (NFAs) are designed and easily synthesized. • Nitrogen-containing six-membered heterocycles are used as the cores of two NFAs. • N⋯S and/or N⋯H interactions are utilized to achieve planar backbones. • Organic solar cells based on two NFAs both show good photovoltaic performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigations on non-fused-ring acceptors with progressive evolutions. • Counterbalance between high photo-response and low energy loss. • J52:O-PC-EH-based device achieved a best efficiency of 14.43% (certified: 14.1%). Resolving competitive counterbalance between high external quantum efficiency (EQE) response and low energy loss is critical for achieving efficient organic solar cells (OSCs), including those based on low-cost non-fused-ring electron acceptor (NFREA). In this work, we performed a comparable study by utilizing four NFREAs with progressive evolutions in molecular structures, energetic levels, spectral coverages, crystallinity, etc, to pair with polymer donor J52. By regulating the terminal and side chains of NFREAs, the enhanced intramolecular charge transfer (ICT) effect allows O-PC-EH possessing the broader spectral coverage for higher photocurrent, the reduced energetic offset enables O-PC-EH-based device owning higher luminescence property for lower energy loss, the strengthened crystallinity endows O-PC-EH-based blend better charge transport property for less charge recombination. With those comprehensive managements from molecule to blend properties, the J52:O-PC-EH-based OSCs achieved the best efficiency of 14.4% (certified: 14.1%) with benefits in all the three device parameters. This work reveals the importance of fine-tuning molecular structures of NFREAs according to paired polymer donor for maximizing the device performances. [ABSTRACT FROM AUTHOR]

Two hole-extraction materials (HEMs), TPP-OMeTAD and TPP-SMeTAD, have been developed to facilitate the fabrication of efficient p-i-n perovskite solar cells (PVSCs). By replacing the oxygen atom on HEM with sulfur (from TPP-OMeTAD to TPP-SMeTAD), it effectively lowers the highest occupied molecular orbital of the molecule and provides stronger PbS interaction with perovskites, leading to efficient charge extraction and surface traps passivation. The TPP-SMeTAD-based PVSCs exhibit both improved photovoltaic performance and reduced hysteresis in p-i-n PVSCs over those based on TPP-OMeTAD. This work not only provides new insights on creating perovskite-HEM heterojunction but also helps in designing new HEM to enable efficient organic-inorganic hybrid PVSCs. [ABSTRACT FROM AUTHOR]

In this paper, a non-fullerene electron acceptor, SF(DPPFB) 4 , which owns a spirobifluorene core and four diketopyrrolopyrrole (DPP) arms end capped by 4-fluorobenzene, is designed and synthesized for solution-processable organic solar cells (OSCs). SF(DPPFB) 4 shows similar absorption bands as those of its non-fluorinated parent compound, SF(DPPB) 4 . However, the terminal fluorine atoms reduce the energy levels of SF(DPPFB) 4 , especially, its lowest unoccupied molecular orbital level decreases by 0.04 eV than that of SF(DPPB) 4 , which enlarges the energy offset between the electron donor and acceptor, favorable for the dissociation of excitons in OSCs. Moreover, the fluorination improves the electron mobility of SF(DPPFB) 4 . Thus, the OSCs with poly(3-hexylthiophene) as the electron donor and SF(DPPFB) 4 as the electron acceptor can provide a maximum power conversion efficiency of 4.42%, with a lifted short-circuit current ( J sc ) of 8.48 mA cm −2 . [ABSTRACT FROM AUTHOR]

Summary: Background: The engagement of the T cell receptor results in actin cytoskeletal reorganization at the immune synapse (IS) and the triggering of biochemical signaling cascades leading to gene regulation and, ultimately, cellular activation. Recent studies have identified the WAVE family of proteins as critical mediators of Rac1-induced actin reorganization in other cell types. However, whether these proteins participate in actin reorganization at the IS or signaling pathways in T cells has not been investigated. Results: By using a combination of biochemical, genetic, and cell biology approaches, we provide evidence that WAVE2 is recruited to the IS, is biochemically modified, and is required for actin reorganization and β-integrin-mediated adhesion after TCR crosslinking. Moreover, we show that WAVE2 regulates calcium entry at a point distal to PLCγ1 activation and IP3-mediated store release. Conclusions: These data reveal a role for WAVE2 in regulating multiple pathways leading to T cell activation. In particular, this work shows that WAVE2 is a key component of the actin regulatory machinery in T cells and that it also participates in linking intracellular calcium store depletion to calcium release-activated calcium (CRAC) channel activation. [Copyright &y& Elsevier]