Inadequate control over aggregation and morphology evolution remains a major constraint in ternary organic solar cells (TOSCs). To address this, two small-molecule donors, C1 and C2, were designed with identical backbones but distinct aromatic connecting units: a phenyl linkage in C1 and a thiophene linkage in C2. It is revealed that steric torsion is utilized by the phenyl linkage in C1 to suppress excessive self-aggregation and induce balanced, mixed-orientation molecular packing. In contrast, the thiophene linkage in C2 promotes a coplanar backbone with tighter, predominantly face-on π-π stacking, leading to over-crystallization. Consequently, C1 facilitates finer interpenetrating networks with redistributed π-π interactions, supporting efficient in-plane charge transport. Benefiting from this optimized morphology and favorable energy alignment, the PM6:Y6:C1 device achieves an outstanding Fill Factor (FF) of 77.90% and a Power Conversion Efficiency (PCE) of 17.98%, significantly outperforming binary devices and the C2-based ternary devices. This work establishes aromatic connecting unit modulation as a pivotal strategy for precisely controlling aggregation and nanoscale morphology in high-performance TOSCs.

Stretchable organic solar cells (SOSCs) are highly desirable for wearable electronics and electronic skins. However, their development has long been limited by the lack of high-performance stretchable active layer materials. In this work, we successfully designed and synthesized one novel donor polymer D18-O-C3 by introducing alkoxy segments into the backbone of polymer donor D18. Research has shown that compared to alkyl segments, the introduction of alkoxy segments can more effectively disrupt the ordered aggregation of polymers, reduce crystallinity, and significantly improve the stretchability of polymers. At the same time, the introduction of alkoxy segments also increases the Lc, optimizes the charge transport characteristics, and achieves a high PCE of 15.50% for the D18-O-C3: PY-IT based device. This study reveals the crucial role of alkoxy-containing segments in balancing photovoltaic and mechanical properties, providing new molecular design strategies for the development of high-performance stretchable photovoltaic materials.

Organic room-temperature phosphorescent (RTP) materials with tunable lifetimes are of great interest for information display, anti-counterfeiting, and data storage. However, achieving both ultralong lifetimes and high quantum yields, particularly in the blue region, remains challenging due to their inherent trade-off. Herein, a site-dictated strategy is employed by introducing pinacol boronate ester (Bpin) groups at the 1-, 2-, and 4-positions of a carbazole scaffold (CZ1B, CZ2B, and CZ4B), and embedding the resulting phosphors into a poly(vinyl alcohol) (PVA) matrix. All three emitters exhibit visible blue RTP with tunable lifetimes ranging from 3.96 s (CZ1B) to 5.20 s (CZ2B)-among the longest reported-along with high phosphorescence quantum yields (17.94-26.95 %). Combined theoretical and experimental studies reveal that Bpin substitution site affects excited-state characteristics, spin-orbit coupling, and hydrogen-bonding interactions with the PVA host. Notably, CZ2B shows optimal excited-state separation, highest surface electrostatic potential, and strongest hydrogen bonding, leading to superior RTP performance. This study presents a precise structural approach to modulate both phosphorescence lifetime and efficiency, offering valuable insight for the development of long-lived blue RTP materials in advanced optical applications such as data storage and visual encryption.

Side-chain engineering has been demonstrated as a simple and effective strategy for modulating molecular morphology and enhancing photovoltaic performance. Here, we synthesized a new small-molecule donor material BTR-YF by tailoring one of the side chains of BTR-Cl and migrating to the opposite side. Compared to BTR-Cl, the BTR-YF counterpart displays a slightly blue-shifted absorption spectrum, a down-shifted highest occupied molecular orbital energy level, and suppressed molecular aggregation, which collectively contribute to an optimized thin-film morphology. Consequently, all-small-molecule organic solar cells based on BTR-YF: L8-BO achieve a remarkable power conversion efficiency of 15.1 %, significantly higher than that of the BTR-Cl-based devices (13.6 %). The improved performance is attributed to enhanced exciton dissociation, more balanced charge transport, and reduced bimolecular recombination. Moreover, the BTR-YF-based devices demonstrate superior long-term stability and thermal stability, benefiting from the favorable nanoscale phase separation and suppressed excessive aggregation enabled by the asymmetric side-chain configuration and migration. This study demonstrates that complete migration of the side chain to the molecular opposite side is an effective approach for improving the performance of all-small-molecule organic solar cells, laying an important foundation for their further commercialization.

Optimizing morphology is essential to enhancing the performance of ternary organic solar cells (TOSCs). Incorporating a third component with suitable crystallinity and aggregation to regulate TOSC morphology proves to be an efficient method for improving device efficiency. In this work, two multifunctional donor small molecules with phenyl isomeric side chains, L1 (C4-Ph) and L2 (Ph-C4), are employed as guest components in the PM6:Y6-based ternary system. The impact of the phenyl positions in their molecular structures on molecular crystallinity, aggregation, and morphology of the TOSC is systematically investigated. The results indicate that the incorporation of 10 wt% L1 significantly improves the morphology of the blend film. Specifically, L1 disrupts the excessive aggregation of PM6 long-chain molecules, improves donor-acceptor compatibility, and reduces phase separation size in the active layer film. Exciton dissociation and charge transport in the active layer are promoted, and the final power conversion efficiency (PCE) increases from 15.97 % to 17.23 %. It is shown that the crystallinity and aggregation of the small molecule donor can be precisely regulated by the side-chain structure, which promotes its synergistic effect with the polymer donor. This approach provides an innovative idea for controlling the morphology of the active layer and improving the device performance.

Recent years have witnessed significant advances in stretchable organic solar cells (SOSCs), positioning them as the most promising supplying power to wearable systems. Nevertheless, further progress in SOSCs is still largely constrained by the development of stretchable light-harvesting active layers. Integrating a third component into the binary system, represent a promising route to simultaneously achieve high photovoltaic performance and enhance mechanical stretchability. In this study, we designed and synthesized a small-molecule donor material (SMD-Asy) characterized by asymmetric side chains and backbone, which was integrated into the PM6:Y6 blend as a guest component. The introduction of fully asymmetric SMD-Asy can modulate the blend film morphology, reduce crystallinity and increase crystal coherence length, thereby leading to a concurrent improvement in both the photovoltaic efficiency and stretchability of the material. Specifically, the organic photovoltaic device employing PM6:SMD-Asy (5%):Y6 ternary blend films achieved a decent power conversion efficiency (PCE) of 16.88% and exhibited better stretchability than the binary PM6:Y6 blend film. The use of an asymmetric small molecule donor enables precise control over the film morphology and crystallization behavior, which underlines a promising approach toward achieving both high efficiency and stretchability in organic solar cells.

Ternary blend strategies are pivotal for maximizing the performance of organic solar cells. Herein the impact of fluorination positional isomerism is investigated by employing two small-molecule donors G1 (para-fluorinated) and G2 (meta-fluorinated) as third components in the PM6:Y6 system. The para-substitution in G1 led to excessive aggregation and morphological disorder constraining the Power Conversion Efficiency (PCE) to 15.52%. In stark contrast the meta-substitution in G2 conferred a critical synergistic advantage. Mechanistically the deep Lowest Unoccupied Molecular Orbital (LUMO) level of G2 establishes an efficient energy cascade that facilitates effective exciton dissociation. More critically the meta-fluorination induces a relatively twisted molecular geometry which translates into a moderate aggregation tendency and a reduced crystallization driving force. These optimized intrinsic properties coupled with excellent miscibility promote a finer and more uniform nanoscale morphology in the blend film. Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) analysis further confirmed that this optimized morphology features a highly coherent lamellar framework with enhanced crystal orientation. It is this superior structural organization that secures highly continuous charge transport pathways thereby enabling an outstanding PCE of 18.05% and a high Fill Factor (FF) of 76.37%. This work confirms that simultaneously optimizing electronic alignment and crucially structural morphology via precise positional fluorination is a vital design principle for achieving high-efficiency ternary photovoltaics.

High mechanical robustness and high photovoltaic performance are essential for the practical application of stretchable organic solar cells (SOSCs) in stretchable and wearable electronics. In this regard, we designed and synthesized a series of novel donor polymers by incorporating amide units with flexible alkyl segments of varying lengths as a third component into the conjugated backbone of the D18 polymer. Tuning the length of these alkyl segments effectively modulates the aggregation behavior and crystallinity of the donor polymers, leading to an optimal blend morphology with the polymer acceptor PY-IT and enhancing both the mechanical and photovoltaic properties of the resulting blend films. Specifically, the solar cell based on the D18-C6:PY-IT blend achieved a high power conversion efficiency of 14.67% and demonstrated excellent stretchability with a crack onset strain of 30%, marking a significant improvement over the reference D18:PY-IT blend. This study elucidates the influence of the alkyl segment length within amide units on polymer crystallinity, providing a strategic approach for the design of high-performance stretchable active layer materials.

Liquid crystalline small molecules have been proven to possess certain advantages in forming a balanced active-layer morphology. In this research, two liquid crystalline small-molecule donors (LC-SMDs) were synthesized. It is found that more flexible groups are beneficial to lowering the liquid crystal (LC) phase transition temperature. LCS6S forms liquid crystals in a relatively low-temperature range (145 degrees C-154 degrees C). LCS8S shows an even lower LC temperature of 130 degrees C-150 degrees C due to its longer terminal alkyl groups. Lowering the LC temperature allows the active layer to be annealed at the LC state and is more compatible with the device fabrication requirements. Photovoltaic performance is significantly improved after the thermal annealing treatment. The device based on LCS8S:Y6 exhibits balanced crystallization and phase separation, and a higher power conversion efficiency of 10.08% is achieved. This work demonstrates that annealing at the LC state is an effective strategy for optimizing device morphology and provides new insights for controlling the LC temperature of LC-SMDs.

The new halogen-free donor polymer PCN6 is constructed using 2-ethylhexyl-4,6-dibromo-3-cyano-thieno[3,4-b]thiophene as acceptor (A) block, and is compared in detail with the commercially available PTB7-Th. It is found that PCN6 has a wider film absorption (300–700 nm) and lower highest occupied molecular orbital (HOMO) energy levels (−5.52 eV) than PTB7-Th (−5.34 eV), suggesting a great advantage of the monocyano-functionalized modification strategy in terms of molecular absorption and energy level tuning. The performance difference between PCN6:Y6- and PTB7-Th:Y6-based organic solar cells (OSCs) is compared by a series of studies including light intensity dependence, carrier mobility, AFM, TEM, and GIWAXS. The results show that PCN6:Y6-based OSCs have stronger crystallinity, better charge transport, higher and more balanced carrier mobility, and less exciton complex loss. Therefore, the power conversion efficiency (PCE) of PCN6:Y6-based OSCs reaches 11.34%, while the PCE of PTB7-Th:Y6-based OSCs is only 9.02%. These results suggest that 2-ethylhexyl-4,6-dibromo-3-cyano-thieno[3,4-b]thiophene is an excellent A block for the construction of halogen-free donor polymers with low HOMO energy levels, and also demonstrate that the introduction of cyano in the conjugated backbone of polymers is a good strategy to achieve high-performance OSCs.

Excessive energy loss ( E loss ) remains a primary bottleneck limiting further efficiency improvements in organic solar cells (OSCs). Mitigating energy losses is therefore a key prerequisite for advancing organic photovoltaic technologies. Rational acceptor molecular design that modulates the dielectric constant and exciton‐vibration coupling of the active layer has emerged as a particularly promising route to achieving this goal. Herein, a platinum‐complex‐based non‐fullerene acceptor (PtHD) is designed and synthesized. The molecule features high planarity and backbone rigidity, which effectively suppresses exciton‐vibration coupling. Integrating the Pt coordination unit amplifies the molecular dipole moment and polarizability, consequently enhancing the dielectric constant of the active layer. A binary device based on D18/PtHD achieves a high open‐circuit voltage of 0.938 V with a reduced E loss of 0.525 eV. Building on this achievement, by introducing PtHD as a guest component into the D18/L8‐BO system and employing a layer‐by‐layer deposition strategy to control the vertical distribution, the ternary device demonstrates an minimized E loss and superior exciton separation, culminating in a remarkably high power conversion efficiency (PCE) of 20.52%. This work highlights the crucial role of metal‐complex acceptors in managing energy loss and charge dynamics, thus providing a molecular design paradigm to develop highly efficient organic photovoltaics.

Stretchable organic solar cells (SOSCs) show remarkable promise to provide energy to wearable electronic devices. Despite the rigid organic solar cells (OSCs) have made power conversion efficiencies (PCEs) of over 20%, tensile properties of these high-performance active layers are often compromised and thus do not make them suitable for stretchable wearable electronic devices. In this regard, we designed a novel donor polymer, PBDTT-Fully-asy, with the fully asymmetric structure of the backbone and side chains, and incorporated it in PM6:Y6 blend to construct a stretchable light-harvesting active layer. Compared with a symmetric structure, the center of the fully asymmetric fused-ring is shifted, which can weaken self-aggregation. In addition, strong twisting and disruption of the aggregation can occur due to the side chain of the rigid benzene ring. Furthermore, the improved backbone coplanarity and increased pi-conjugation are advantageous for improving the charge transfer ability and photovoltaic performance. Our obtained results suggest that incorporation of PBDTT-Fully-asy (10 wt%) can efficiently improve the stretchability and photovoltaic performance. Our proposed molecular design approach will contribute to the acceleration of high-performance stretchable.

Stretchable organic solar cells (SOSCs) have great application prospects to serve as energy supply systems, which can be fully incorporated with wearable electronic devices to achieve truly integrated systems that are fully stretchable and wearable. However, the stretchable polymer light-harvesting active layer has not been successfully developed, which limits the development of stretchable organic solar cells. In this regard, a series of stretchable light-harvesting donor and acceptor polymers are designed and synthesized by introducing amide units with flexible alkyl segments and hydrogen bonds as the third component into the PM6 and PY-IT based conjugated polymer backbones. Hydrogen bonds and flexible alkyl segments can dissipate tensile stress for high stretchability. In addition, hydrogen bonds can reduce the impact of flexible alkyl segments on intermolecular stacking, thus maintaining good photovoltaic performance. The obtained results suggest that the incorporation of amide units (5 mol% content) into the donor polymer can efficiently improve the stretchability without compromising the photovoltaic performance. This study provides an understanding of the impact of amide units on properties, offering another entry to the molecular design guidelines for high-performance stretchable light-harvesting polymers, developing high-performance stretchable organic solar cells, and further promoting the development of wearable electronic devices.

Morphology control of the active layer is the key to achieving a high power conversion efficiency (PCE) for organic solar cells (OSCs). The strategy of incorporating small molecule donors as the third component to construct ternary OSCs has emerged as an effective approach to regulate morphology. In this regard, we employed an asymmetric strategy to synthesize the small molecule donor SBDT-Asy. In the asymmetric core, the rigid benzene ring was employed as one side chain, which was expected to disrupt the self-aggregation and stir the PM6:Y6 host blend. For the other side chain, we introduced alkoxyl chains to improve solubility. As a result, the ideal film morphology could be achieved. Benefiting from enhanced exciton dissociation and charge transport resulting from the good morphology, the PCE of PM6:Y6:SBDT-Asy ternary devices increased to 17.68%. The results presented in this work suggest that introducing small molecules containing an asymmetric core is an effective approach to develop high-efficiency ternary OSCs.

Photoelectrochemical (PEC) systems hold great potential for producing value-added chemicals through the selective oxidation of alcohols in an environmentally friendly manner. However, previous efforts have been hindered by low quantum efficiency, poor selectivity and instability of the photoanodes. To address these issues, we demonstrate the oxidation of benzyl alcohol (BA) into benzaldehyde (BAD) with state-of-the-art efficiency and selectivity using CdS photoanodes incorporated with gold nanoparticles as catalytic sites and sulfites which allow the photoanode to operate through a radical process in near-neutral conditions. This synergistic approach allows the typically vulnerable CdS-based photoanode to maintain PEC Faradaic efficiencies exceeding 95 % for BAD production over 20 h with >99 % selectivity (at pH 9 and 0.6 V versus RHE). The Au-SO32- adduct, formed by the strong adsorption of sulfite replacing traditional oxygen/hydroxyl species on the CdS surface, actively catalyzes the selective oxidation of BA. This novel PEC pathway offers a sustainable approach for organic molecule conversion and provides a model for designing efficient PEC processes for solar energy utilization.

Developing stable and efficient nonprecious‐metal‐based oxygen evolution catalysts in the neutral electrolyte is a challenging but essential goal for various electrochemical systems. Particularly, cobalt‐based spinels have drawn a considerable amount of attention but most of them operate in alkali solutions. However, the frequently studied Co–Fe spinel system never exhibits appreciable stability in nonbasic conditions, not to mention attract further investigation on its key structural motif and transition states for activity loss. Herein, we report exceptional stable Co–Fe spinel oxygen evolution catalysts (~30% Fe is optimal) in a neutral electrolyte, owing to its unique metal ion arrangements in the crystal lattice. The introduced iron content enters both the octahedral and tetrahedral sites of the spinel as Fe2+ and Fe3+ (with Co ions having mixed distribution as well). Combining density functional theory calculations, we find that the introduction of Fe to Co3O4 lowers the covalency of metal‐oxygen bonds and can help suppress the oxidation of Co2+/3+ and O2−. It implies that the Co–Fe spinel will have minor surface reconstruction and less lattice oxygen loss during the oxygen evolution reaction process in comparison with Co3O4 and hence show much better stability. These findings suggest that there is still much chance for the spinel structures, especially using reasonable sublattices engineering via multimetal doping to develop advanced oxygen evolution catalysts.

Photoelectrocatalytic approaches show promise for contaminate removal in wastewater through redox reactions. However, the direct treatment of very low concentration heavy metals is a challenging task. Copper bismuth oxide is considered as a potential photocathode material due to its appropriate bandgap width and excellent light absorption properties. In this work, we utilize copper bismuth oxide photoelectrodes with micrometer-scale pores to achieve the efficient and complete reduction of micromolar-level hexavalent chromium(VI) in wastewater. In a continuous 180 min experiment, the reduction rate of 5 µM hexavalent chromium reached 97%, which is an order lower than the drinking standard. Such a process was facilitated by the unique hierarchical microstructure of the oxide thin film and the porous morphology. On the other hand, the structural evolution during the operation was analyzed. A surface passivation was observed, suggesting the possible long-term practical application of this material. This study serves as an important reference for the application of photoelectrocatalysis in addressing Cr(VI) pollution in wastewater, with implications for improving water quality and environmental protection.

In order to expand the application of bismuth vanadate (BiVO4) to the field of photoelectrochemistry, researchers have explored the potential of BiVO4 in catalyzing or degrading organic substances, potentially presenting a green and eco-friendly solution. A study was conducted to investigate the impact of electrolytes on the photocatalysis of benzyl alcohol by BiVO4. The research discovered that, in an acetonitrile electrolyte (pH 9) with sodium bicarbonate, BiVO4 catalyzed benzyl alcohol by introducing saturated V5+. This innovation addressed the issue of benzyl alcohol being susceptible to catalysis in an alkaline setting, as V5+ was prone to dissolution in pH 9 on BiVO4. The concern of the photocorrosion of BiVO4 was mitigated through two approaches. Firstly, the incorporation of a non-aqueous medium inhibited the formation of active material intermediates, reducing the susceptibility of the electrode surface to photocorrosion. Secondly, the presence of saturated V5+ further deterred the leaching of V5+. Concurrently, the production of carbonate radicals by bicarbonate played a vital role in catalyzing benzyl alcohol. The results show that, in this system, BiVO4 has the potential to oxidize benzyl alcohol by photocatalysis.

This comprehensive review delves into the intricacies of the photoelectrochemical (PEC) water splitting process, specifically focusing on the design, fabrication, and optimization of particle-based photoelectrodes for efficient green hydrogen production. These photoelectrodes, composed of semiconductor materials, potentially harness light energy and generate charge carriers, driving water oxidation and reduction reactions. The versatility of particle-based photoelectrodes as a platform for investigating and enhancing various semiconductor candidates is explored, particularly the emerging complex oxides with compelling charge transfer properties. However, the challenges presented by many factors influencing the performance and stability of these photoelectrodes, including particle size, shape, composition, morphology, surface modification, and electrode configuration, are highlighted. The review introduces the fundamental principles of semiconductor photoelectrodes for PEC water splitting, presents an exhaustive overview of different synthesis methods for semiconductor powders and their assembly into photoelectrodes, and discusses recent advances and challenges in photoelectrode material development. It concludes by offering promising strategies for improving photoelectrode performance and stability, such as the adoption of novel architectures and heterojunctions.

To fabricate a high-efficiency bulk-heterojunction (BHJ)-based photocathode, introducing suitable interfacial modification layer(s) is a crucial strategy. Surface engineering is especially important for achieving high-performance photocathodes because the photoelectrochemical (PEC) reactions at the photocathode/electrolyte interface are the rate-limiting process. Despite its importance, the influence of interfacial layer morphology regulation on PEC activity has attracted insufficient attention. In this work, RuO2, with excellent conductivity, capacity and catalytic properties, is utilized as an interfacial layer to modify the BHJ layer. However, the homogeneous coverage of hydrophilic RuO2 on the hydrophobic BHJ surface is challenging. To address this issue, a Pt nanoparticle-assisted homogeneous RuO2 layer deposition method is developed and successfully applied to several BHJ-based photocathodes, achieving superior PEC performance compared to those prepared by conventional interface engineering strategies. Among them, the fluorine-doped tin oxide (FTO)/J71:N2200(Pt)/RuO2 photocathode generates the best photocurrent density of -9.0 mA cm(-2) at 0 V with an onset potential of up to 1.0 V under AM1.5 irradiation.