Currently, polyurethane (PU) elastomers are widely utilized in various industrial fields, but their weak recyclability and flammable nature hinder further development. To overcome these challenges, we developed a novel molecular design strategy via introducing dual chain extenders of benzotriazine (BGA) and 1,3-bis(3-aminopropyl)tetramethyldisiloxane (siloxane) to the PU main chains. The synergistic interaction between the newly developed BGA and siloxane induces micro-phase separation in the polymer matrix, overcoming the limitations of conventional single-chain extenders. Here, the rigid BGA segments effectively enhance the intermolecular interactions, thereby reinforcing the molecular framework. Simultaneously, the flexible siloxane chains promote the micro-phase separation and result in a characteristic aggregated morphology on the PU surface. This strategy yields a new elastomer of PU-BGA/Si4% with a tensile strength of 15.08 MPa and an elongation at break of 1608%, achieving a remarkable balance between strength and flexibility. Moreover, PU-BGA/Si4% demonstrates excellent recyclability, retaining significant mechanical properties after recycling. Significantly, the existence of nitrogen (N) and silicon (Si) elements imparts self-extinguishing properties to PU-BGA/Si4%, making it suitable for use in fire-prone environments. Benefiting from this reliable self-extinguishing behavior, PU-BGA/Si4% has also been successfully used as an encapsulation material for electronic pressure-sensing films, where flame suppression is essential for device safety and stability. Therefore, this approach offers a promising strategy for developing high-performance, recyclable, and self-extinguishing PU elastomers for future applications in advanced materials.

Conventional fullerene-based electron transport materials (ETMs) suffer from limited tunability and suboptimal interfacial contact, hindering further efficiency improvements in inverted perovskite solar cells (PSCs). In this study, two non-fullerene small molecules with chlorinated thiophene terminal groups Cl24-TCl and difluorinated phenyl terminal groups Cl24-F were employed as ETMs in inverted PSCs to investigate the key factors by which different terminal groups influence device performance. Although the Cl24-TCl ETM exhibits a more polarized electrostatic potential distribution and a larger dipole moment, the Cl24-F ETM shows more favorable energy level alignment and interfacial contact, which effectively reduce interfacial charge recombination losses. In addition, Cl24-F displays more compact π-π stacking, resulting in higher electron mobility and conductivity, thereby promoting more efficient interfacial charge transport. Consequently, inverted PSCs based on Cl24-F achieve a champion efficiency of 24.18%, which is significantly higher than that of devices based on Cl24-TCl (13.02%). This work uncovers the key factors governing device performance and guides the design of high-performance non-fullerene ETMs.

Self-assembled monolayers (SAMs) have proven to be highly efficient hole-transporting layers (HTLs) due to their advantages, including low cost, minimal material consumption, ease of synthesis, negligible optical loss, and exceptional stability. Recently, carbazole-based SAM HTLs have considerably improved the power conversion efficiency (PCE) of organic solar cells (OSCs) and perovskite solar cells (PSCs)—with PCEs reaching 21% and 27%, respectively. This review begins with a concise overview of the chemical structure of SAMs, emphasizing the recent advancements achieved by carbazole-based SAMs in the photovoltaics (PVs) sector. We then systematically summarize the modifications made to the chemical structure of carbazole-based SAMs to optimize their interface dipole, surface wettability, and interface defects. Especially for functional group, the modification techniques are categorized into four main types: methoxylation, conjugation, halogenation, and asymmetrization. Finally, several challenges, including solubility, film quality, and stability, along with potential solutions for these issues are discussed. We hope this review serves as a valuable guide and source of inspiration for the design of SAM HTLs, ultimately enhancing the performance of PV devices.

Rational molecular engineering of cathode interlayers (CILs) is critical for boosting photovoltaic performance in organic solar cells (OSCs). Herein, a perylene diimide (PDI)-based CIL (PDINB-BP) is synthesized via quaternization strategy. The quaternary ammonium groups in PDINB-BP endow it with a strong molecular dipole moment, excellent alcohol solubility, and facile synthesis, while suppressing excessive aggregation when depositing CIL. As a result, PDINB-BP efficiently modulates the work function (WF) of silver (Ag) electrode from 4.68 to 3.98 eV. Furthermore, it also enhances the interfacial CIL-cathode adhesion, reduces defects, and induces a strong oriented interfacial dipole at cathode interface to accelerate electron transport and suppress charge carrier recombination. Through using PDINB-BP as CIL, the binary OSC achieves a champion power conversion efficiency (PCE) of 20.26% and an excellent fill factor (FF) of 81.26%. To the best of our knowledge, this PCE is one of the highest reported data by using a very simple-structured PDI-based CIL in a binary OSC. Moreover, PDINB-BP integrates a broad universality within various active layers including non-fullerene and all-polymer systems, excellent thermal stability, and remarkable thickness tolerance. This practical quaternization engineering in CIL design offers a feasible strategy for developing high-efficiency and stable OSCs.

Solution-processable cathode interfacial materials (CIMs) in organic solar cells (OSCs) inherently suffer from limited conductivity and charge transfer capabilities, which in turn restrict device efficiency. In this study, we report a double-doped CIM, PDINN-CNT2N, which combines organic PDINN with aminated carbon nanotubes through a reciprocal doping strategy. This strategy leverages intramolecular self-doping and intermolecular reciprocal doping between the two components to markedly enhance the electron density and charge transport properties of the developed CIM. Simultaneously, the intermolecular interactions effectively optimize molecular assembly, thereby reinforcing the electron mobility within the films. OSCs utilizing the PDINN-CNT2N CIM demonstrate improved conductivity and electron mobility while reducing charge recombination. Consequently, OSCs based on binary D18:L8-BO achieve an efficiency of 20.05% with superior stability. The widespread applicability of this strategy is further confirmed across additional CNT2N-based CIMs and various active layer systems, significantly enhancing the efficiency to 20.72% (certified as 20.33%) in a ternary system. The study provides essential insights into molecular synergistic doping and presents a universal approach for designing high-performance CIMs that are suitable for scalable solution processing.

A dual functional perylene diimide derivatives exhibiting a remarkable efficiency of 20.25% for organic solar cells and an excellent evaporation rate 3.7 kg m −2 ·h −1 for interfacial solar steam generation.

Intrinsically stretchable organic photovoltaics (IS-OPVs) demand both high power conversion efficiency (PCE) and robust mechanical deformability, yet these requirements are often difficult to reconcile in state-of-the-art donor : acceptor blends. Existing toughening strategies typically rely on complicated synthesis and compromise the device PCE. Here, we report a synthesis-free toughening strategy based on commercially available chlorinated polyolefin (PP-Cl), which is low-cost, scalable, solution-processable, and broadly compatible with diverse high-performance donor : acceptor blends. This strategy enables mechanically resilient IS-OPVs without sacrificing photovoltaic performance. At an optimal loading, rigid PM6:BTP-eC9 devices show a reproducible increase in PCE, while the corresponding stretchable devices possess over 60% efficiency retention at 40% strain. In contrast, undoped controls undergo severe degradation at 20% strain. The same strategy is further extended to a ternary rigid D18:BTP-eC9:L8-BO system, delivering PCEs up to 20.5%, and the corresponding active-layer engineered intrinsically stretchable devices are among the highest reported IS-OPVs. Assisted by a mechanical framework and the Coran-Patel model, multiscale characterization suggests that chlorine-involved reversible weak interactions act as sacrificial stress-dissipation pathways. These results establish chlorinated polyolefins as practical toughening additives for high-efficiency stretchable organic photovoltaics.

Insufficient surface coverage persists as a critical limitation for self-assembled monolayers/multilayers (SAMs/SAMULs) in photovoltaic field. The co-assembled SAMULs (Co-SAMULs) strategy, which incorporates a guest self-assembled molecule, offers an effective solution. However, the working mechanism of the guest molecule is still not fully understood. Herein, benzo[b]thien-2-ylboronic acid (BBA) was introduced as a guest material into the host molecule system based on (4-(3,6-di(thiophen-3-yl)-9H-carbazol-9-yl)butyl) phosphonate (4PAThCz) to construct efficient Co-SAMULs. We found that BBA can fused into 4PAThCz micelles rather than forming individual micelles, respectively, thereby inhibiting micelle growth. During the film-forming process, BBA engages in synergistic adsorption with the host molecules, selectively fills the voids between host molecule and substantially improving surface coverage. Such a homogeneous and high-quality film effectively suppresses surface defect states, enhances interfacial charge transport capacity and minimizes non-radiative exciton recombination. As a result, a champion power conversion efficiency (PCE) of 21.26% (certificated as 20.79%) with an outstanding fill factor (FF) of 83.54% is achieved, representing the highest performances reported for organic solar cells (OSCs) to date.

ABSTRACT The π‐extension strategy represents a highly effective approach toward improving the charge transport capability of self‐assembled monolayers/multilayers. Nevertheless, highly conjugated molecular backbones readily trigger intense intermolecular interactions, which further cause severe molecular aggregation and incomplete surface coverage of the assembled films. Here, we synthesized a unilateral π‐expanded self‐assembled molecule, namely (4‐(3‐(2‐chlorothiophen‐3‐yl)‐9H‐carbazol‐9‐yl)butyl)phosphonic acid) (Cl‐4PAThCz). The unilateral π‐extension design of Cl‐4PAThCz disrupts the molecular symmetry, which in turn optimizes its critical micelle concentration and micelle size in solution. This unique solution property is beneficial to the subsequent formation of a uniformly covered film without large‑scale molecular aggregation. Such a high‐quality film enables effective passivation of interfacial defects, accompanied by enhanced electrical conductance and hole transport capacity. Consequently, a champion efficiency of 20.77% (certified to 20.31%) with an outstanding fill factor of 83.16% was achieved, which is among the state‐of‐the‐art efficiencies for OSCs. This work clarifies the mechanism behind asymmetrical self‐assembled molecules, affording valuable guidance for the materials design of organic semiconductor.

Solid additives, as an efficient approach of morphology control in organic solar cells (OSCs), remain not fully understand in terms of the influence of their intermolecular interactions with photoactive molecules on morphological evolution and ultimate device performance. Herein, the intermolecular interactions between solid additives and photoactive molecules were precisely tuned through molecular isomerization engineering. Three isomers of iodine-substituted 1,2,4-trichlorobenzene were adopted as the solid additives. The four strongly electronegative halogen atoms readily produce intense interactions with the photoactive materials, thereby enhancing their J-type stacking and broadening the absorption spectrum. Crucially, the iodine substituent position on the solid additives was altered, which improved their miscibility and intermolecular interactions with photoactive materials, forming a bicontinuous interpenetrating network. Consequently, the binary OSCs achieved an impressive fill factor of approximately 84% with an efficiency of nearly 21% (certified as 20.42%), ranking among the top OSC performances to date. Furthermore, the device demonstrated excellent storage stability, with an extrapolated T80 (maintaining 80% of its initial efficiency) exceeding 10 000 h.

SiOx is a promising anode for lithium-ion batteries, but practical use is hindered by low conductivity, large volume changes, and unstable interfaces. Here, a mild strategy is reported to fabricate a SiOx@RF@CNTs composite anode with a hollow mesoporous architecture and dual-carbon modification. Mesoporous SiO2 nanospheres are converted into hollow structures by hot-water treatment, which selectively etches the relatively loose interior through mesoporous channels and enables tuning of particle size and shell thickness without harsh acidic or alkaline etchants. The hollow SiO2 is then coated with resorcinol-formaldehyde resin and combined with carbon nanotubes to build a conductive network. After thermal treatment in an inert atmosphere, SiO2 is partially reduced to nonstoichiometric SiOx. XPS depth profiling reveals depth-dependent chemical-state variation during this conversion. Owing to synergistic structural buffering, improved interfacial stability, and enhanced charge transport, the electrode delivers 464.8 mAh g- 1 after 500 cycles at 1 A g- 1, with good rate capability and favorable kinetics.

ABSTRACT Self‐assembled monolayers suffer from the insufficient electrical conductivity, stemming from their ultrathin nature and disordered molecular orientation. Here we report a π‐skeleton unit of 3,6‐dibenzothiophen‐9 H ‐carbazol to building a self‐assembled multilayer (SAMUL) that exhibits superior carrier transport and outstanding resistance to external stimuli. The π‐expanded skeleton effectively enhanced the molecular crystallinity and face‐on orientation, which successfully activated a large π‐electron conjugated network within SAMULs. This conjugated network structure greatly broadens the delocalization region of free radicals, which not only significantly enhances the electrical conductance and hole‐transporting capability, but also reinforces the photochemical stability. Consequently, a record‐high efficiency of 21.13% (certified as 20.77%) with a notable fill factor of 83.48% was achieved for binary organic solar cells. This work provides a new inspiration for the molecular skeleton design in organic electronics.

Acquiring a versatile polyurethane (PU) elastomer with both high mechanical properties and rapid low-temperature healing for flexible nanosensors represents a significant challenge. Inspired by the synergistic effects of dynamic bonds, we introduce the dynamic sextuple hydrogen bonds (H-bonds) from adipic dihydrazide (AD) and flexible dynamic disulfide bonds (S-S bonds) from the chain extender 3,3 '-dithiobis(2-butanol) (DS) into PU main chains to fabricate a high-performance elastomer (PU-3) with remarkable mechanical robustness and rapid self-healing capability. Specifically, AD imparts PU-3 with an exceptional tensile strength of 40.5 MPa and a toughness of 287.8 MJ m-3. A 1.1 g sample (50 mm & times; 10 mm & times; 1.3 mm) supports loads up to 11,000 times its own weight. In addition, the excellent DS unit, featuring four branched methyl groups with a substantially larger molecular volume, renders the PU-3 more flexible with an outstanding elongation at break of 1445.2%. Moreover, PU-3 exhibits excellent resilience, self-healing efficiency, and recyclability. As a result, a flexible polymer/carbon nanotube composite nanosensor is constructed from this elastomer matrix and multiwalled carboxylated carbon nanotubes (MWCNTs-COOH) as the conductive filler, exhibiting outstanding sensitivity and rapid response and recovery capabilities, thereby highlighting its potential for applications in health monitoring and intelligent wearable electronics.

Imidazo[1,5-a]isoquinolin-1-amine is a common structural motif in pharmaceuticals and a promising bioisostere of imidazo[1,2-a]pyridin-3-amine. However, most synthetic routes to this scaffold are limited by their reliance on external chemical oxidants and prefunctionalized substrates. In this article, silver-catalyzed [2 + 1 + 2] cycloaddition with isocyanide is first realized with the aid of microwave irradiation. Notably, isocyanide could serve as crucial "CN" and "C1" synthons for the first time in isocyanide chemistry. Screening of all synthesized compounds against the DU145, A549, and HCT116 cell lines revealed that the imidazo[1,5-a]phthalazin-1-amine derivative exhibits enhanced anticancer activity compared to its bioisostere, with an IC50 value of 9.97 μM against HCT116. This synthetic approach not only offers an efficient bond-forming alternative for imidazo[1,5-a]isoquinolin-1-amines for medicinal chemistry, but also provides novel insights into isocyanide chemistry.

Ternary strategy has been proved very effective to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). However, quaternary OSCs (QOSCs), containing four components in the active layer, have been rarely reported due to the complexity of material synthesis and optimization of active layer composition. Here, we developed a simple method to fabricate high-performance QOSCs by using "multiple-birth-acceptor" (MBA), a mixture of three molecules synthesized simultaneously. These A-DA'D-A type MBAs (MBA31, MBA11, MBA13, and MBA19) were synthesized by reacting one DA'D-type central segment (BTP-2CHO) with two A terminal units (γ-IC-Cl and IC-2Cl) with different feed ratios (γ-IC-Cl: IC-2Cl = 3:1, 1:1, 1:3, and 1:9). Without the need to isolate individual components, these MBAs can be utilized directly as electron acceptor to fabricate QOSCs. Compared with binary and ternary devices, QOSCs based on PM6: MBAs exhibit dramatically improved PCEs. Further device optimization, by using 2PACz as hole transport layer and DIB as an additive, PM6:MBA13-based device achieves a state-of-the-art PCE of 20.10%, among the highest values reported for QOSCs to date. Obviously, this method simplifies the material synthesis and device fabrication process for QOSCs. This study provides a feasible method to synthesize MBAs and subsequently fabricate high-performance QOSCs, and thereby opens up a new venue for the further optimization of OSCs.

The bulk-heterojunction (BHJ) system, denoted as a physical blend film, is a complex system in organic solar cells (OSCs), which is extremely dependent on the phase separation of active layer for achieving high photovoltaic performance. In this work, a novel solvent additive, 1, 8-diiodooctane (DIO), is utilized to regulate phase separation of a D18:Y6 BHJ system. Thanks to the introduction of DIO, it can realize versatile morphology control via extracting acceptor from the donor/acceptor blend phase, decreasing phase mixing. Simultaneously, it enhances the crystallinity of both donor and acceptor synergistically, resulting in a high-purity and bicontinuous interpenetrating network, which reduces the charge recombination significantly. As a result, a champion efficiency of 19.35 % is achieved with an excellent fill factor (FF) of 80.84 %, representing the current highest power conversion efficiency (PCE) reported for D18:Y6-based binary OSCs. Surprisingly, benefiting from the improved morphology regulation, the stability of this binary OSC is improved dramatically, where a unencapsulated device shows a higher storage stability with a T85 of > 5000 h than the control device of 2000 h. Hence, these results indicate that the incorporation of appropriate additive engineering can realize high and stable photovoltaic performance feasibly, which is beneficial for further commercial application of BHJ OSCs.

Realizing low dark current density (Jd) while maintaining high photoresponse is crucial yet challenging for organic photodetectors (OPDs). In this work, two nonplanar small molecule electron acceptors, BTTPCN-F and BTTPCN-Cl, were developed. The OPDs based on them achieved ultralow Jd down to 2.95 × 10-13 A cm-2 and exceptionally high shot noise-limited detectivity (Dsh*) up to 1.12 × 1015 Jones, which are the lowest Jd and highest Dsh* reported for self-powered OPDs to date. The ultralow Jd is attributed to the high reorganization energy and small intermolecular electronic coupling in these nonplanar molecules. On the other hand, their large molecular dipole moment and high dielectric constant contribute to low exciton binding energy, leading to high photoresponse. Consequently, they can work as effective dark current suppressors for achieving high-performance binary or ternary OPDs. A dynamic gesture recognition system based on BTTPCN-Cl OPD was developed, which can accurately identify the gesture input. This work unveils the great potential of high dielectric constant nonplanar organic semiconductors for photodetection.

Organic solar cells (OSCs) represent a promising advancement in photovoltaic technology, characterized by their low production costs, flexibility, and compatibility with large-scale solution processing. Recent developments have propelled the power conversion efficiency (PCE) of OSCs beyond 20 %. This progress is attributed to significant innovations in the materials used for the active layer, including both donor and acceptor components, as well as advancements in device engineering and the incorporation of interfacial materials. Cathode interfacial materials (CIMs) are particularly crucial for enhancing the photovoltaic performance of OSCs. They facilitate the formation of efficient ohmic contacts between the active layer and the cathode, lower the work function (WF) of the cathode, and optimize charge transport characteristics within the devices. This review meticulously examines the evolution of CIMs, analyzing them through various lenses: material types, molecular structures, processing techniques, and operational mechanisms. Moreover, we explore recent breakthroughs in CIMs tailored for OSC applications, categorizing them based on their functionalities and their impact on improving the efficiency of OSCs. This comprehensive overview aims to provide insights into the critical role of CIMs in the ongoing development of OSC technology, highlighting their potential to drive future advancements in the field.

Compared to conventional organic solar cells (OSCs) with acidic PEDOT:PSS as the hole transport layer (HTL), inverted OSCs (i-OSCs) with zinc oxide (ZnO) as the electron transport layer (ETL) display significant advantages in terms of high stability. However, an obvious limitation in i-OSCs is that the sol-gel processed ZnO layers possess detrimental defects at the interface, which hinders the improvement of its photovoltaic performance. To address this problem, a natural, and green dextran (Dex) is used as an efficient interfacial passivator to modify the ZnO layer, thereby achieving enhanced device performance in i-OSCs. The introduction of the Dex passivator efficiently suppresses the interfacial recombination loss, resulting in higher power conversion efficiencies (PCEs). Interestingly, Dex-passivated ZnO exhibits broad applications as an ETL for different types of i-OSCs, including fullerene, non-fullerene, and all-polymer OSCs, in which the D18:Y6 system gives the highest PCE of 18.32%. This is one of the highest values reported for binary i-OSCs. Moreover, the application of Dex significantly improves the device stability, and the T80 lifetimes based on PM6:Y6, D18:Y6, and PM6:PY-IT exceed 1500 h. These results imply that Dex is an excellent interfacial passivator for ZnO-based ETL for high-efficiency and stable i-OSCs.