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Article Highlights By modulating the crystalline properties of the active layer with dual donors, the efficiency of organic solar cells reaches 19.23%. The introduction of PTzBI-dF suppresses the accumulation of traps and charge recombination, allowing ternary devices to maintain 82% of their initial power conversion efficiency (PCE) after illumination for 800 h. The dual-donor strategy for modulating the crystallinity of the active layer is applicable to a variety of Y6 derivatives, and the increase in PCE exceeds 1%.

When used in organic solar cells, poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) aligns interfacial energy levels, promotes hole extraction, blocks electrons, and optimizes the active layer’s morphology. However, with an optimal thickness of approximately 30–40 ​nm, PEDOT:PSS has insufficient layer thickness tolerance, owing to its low conductivity and hole extraction property. Herein, a hole-selective-molecule doping strategy is proposed to enhance the properties of PEDOT:PSS by introducing MPA2FPh-BT-BA (abbreviated as 2F) into its layer. 2F assembles at the anode to form interfacial dipoles due to its unique donor–acceptor–anchor molecular configuration, altering the anode work function and hole-selective extraction. Additionally, 2F improves the aggregation properties of PEDOT:PSS by forming hydrogen bonds with the PSS group, enhancing the conductivity characteristics. These changes in the PEDOT:PSS layer further influence the overlaying morphology, leading to increased crystalline features of PM6 and the bulk heterojunction of PM6:Y6. When a 2F-PEDOT:PSS (2FPP) layer is used, power conversion efficiencies of 18.3%, 19.2%, and 19.1% are achieved in PM6:Y6, PM6:BTP-eC9, and PM6:L8-BO devices, respectively, outperforming counterparts with PEDOT:PSS. Specifically, the performance of PM6:Y6 devices with a 2FPP layer of 170 ​nm remains at > 15%, providing valuable guidance for designing a thickness-insensitive hole transport layer for high-efficiency organic solar cells.

Electrolyte‐gated organic synaptic transistors (EGOSTs) have shed light on their potential in bioelectronics and neuromorphic computing. Numerous research have been studied to modulate their electrochemical doping performance and formulate a simple approach to control iontronics through the side‐chain modulations; however, the effects of alkyl groups as side moieties have not been studied in detail on EGOSTs. Herein, the structural and electrical properties of conjugated polymers are systematically controlled through copolymerization with two different‐alkyl group‐derived monomers for enhancing the nonvolatile characteristics of EGOSTs. The relationships between crystal orientation and electrochemical doping states of conjugated copolymers, which varied with the different copolymerization ratios, are revealed. Also, the behavior of biological synapses, including paired‐pulse facilitation, spike timing‐dependent plasticity, and long‐term potentiation/depression, are successfully simulated. In this study, new avenues are opened for the implementation of neuromorphic devices through side‐chain engineering by showing that the alkyl chain modulates the doping performance.

Abstract Thermoelectric (TE) charge transport in organic TE nanocomposite systems is a critical consideration in designing high‐performance TE materials. Here, the relationship between the TE properties and energy structure of conducting polymer/quantum dot (QD) nanocomposites is systematically investigated by developing a potential wall or potential well in poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with CdTe QDs. The added QDs are primarily distributed within the electrically insulating PSS shell and act as stepping stones for charge transport between PEDOT‐rich grains. The embedded QDs generate an energy‐filtering effect, which is induced by both potential wall and potential well states established by the QDs in the PEDOT:PSS films. The induced energy‐filtering effect increases the Seebeck coefficient S with limited loss of electrical conductivity σ, thereby overcoming the TE trade‐off relation S ∝ σ −1/4. The energy‐filtering effect is optimized by carefully controlling the QD size. The PEDOT:PSS/QD nanocomposite containing the smallest QDs exhibits a power factor of 173.8 µW m−1 K−2, which is 80% larger than the value for the pristine PEDOT:PSS film. This work suggests a strategy for designing TE nanocomposites with improved TE performance and emphasizes the importance of fine‐tuning the interfacial energy gap to achieve an effective energy‐filtering effect.

Abstract The pressing demand for sustainable energy storage solutions has spurred the burgeoning development of aqueous zinc batteries. However, kinetics-sluggish Zn2+ as the dominant charge carriers in cathodes leads to suboptimal charge-storage capacity and durability of aqueous zinc batteries. Here, we discover that an ultrathin two-dimensional polyimine membrane, featured by dual ion-transport nanochannels and rich proton-conduction groups, facilitates rapid and selective proton passing. Subsequently, a distinctive electrochemistry transition shifting from sluggish Zn2+-dominated to fast-kinetics H+-dominated Faradic reactions is achieved for high-mass-loading cathodes by using the polyimine membrane as an interfacial coating. Notably, the NaV3O8·1.5H2O cathode (10 mg cm−2) with this interfacial coating exhibits an ultrahigh areal capacity of 4.5 mAh cm−2 and a state-of-the-art energy density of 33.8 Wh m−2, along with apparently enhanced cycling stability. Additionally, we showcase the applicability of the interfacial proton-selective coating to different cathodes and aqueous electrolytes, validating its universality for developing reliable aqueous batteries.

Abstract For organic solar cells to be competitive, the light-absorbing molecules should simultaneously satisfy multiple key requirements, including weak-absorption charge transfer state, high dielectric constant, suitable surface energy, proper crystallinity, etc. However, the systematic design rule in molecules to achieve the abovementioned goals is rarely studied. In this work, guided by theoretical calculation, we present a rational design of non-fullerene acceptor o-BTP-eC9, with distinct photoelectric properties compared to benchmark BTP-eC9. o-BTP-eC9 based device has uplifted charge transfer state, therefore significantly reducing the energy loss by 41 meV and showing excellent power conversion efficiency of 18.7%. Moreover, the new guest acceptor o-BTP-eC9 has excellent miscibility, crystallinity, and energy level compatibility with BTP-eC9, which enables an efficiency of 19.9% (19.5% certified) in PM6:BTP-C9:o-BTP-eC9 based ternary system with enhanced operational stability.

Abstract The water surface provides a highly effective platform for the synthesis of two-dimensional polymers (2DP). In this study, we present an efficient on-water surface synthesis of crystalline monolayer 2D polyimide (2DPI) through the imidization reaction between tetra (4-aminophenyl) porphyrin (M1) and perylenetracarboxylic dianhydride (M2), resulting in excellent stability and coverage over a large area (tens of cm2). We further fabricate innovative organic-inorganic hybrid van der Waals heterostructures (vdWHs) by combining with exfoliated few-layer molybdenum sulfide (MoS2). High-resolution transmission electron microscopy (HRTEM) reveals face-to-face stacking between MoS2 and 2DPI within the vdWH. This stacking configuration facilitates remarkable charge transfer and noticeable n-type doping effects from monolayer 2DPI to MoS2, as corroborated by Raman spectroscopy, photoluminescence measurements, and field-effect transistor (FET) characterizations. Notably, the 2DPI-MoS2 vdWH exhibits an impressive electron mobility of 50 cm2/V·s, signifying a substantial improvement over pristine MoS2 (8 cm2/V·s). This study unveils the immense potential of integrating 2D polymers to enhance semiconductor device functionality through tailored vdWHs, thereby opening up exciting new avenues for exploring unique interfacial physical phenomena.

Abstract Interest has grown in services that consume a significant amount of energy, such as large language models (LLMs), and research is being conducted worldwide on synaptic devices for neuromorphic hardware. However, various complex processes are problematic for the implementation of synaptic properties. Here, synaptic characteristics are implemented through a novel method, namely side chain control of conjugated polymers. The developed devices exhibit the characteristics of the biological brain, especially spike‐timing‐dependent plasticity (STDP), high‐pass filtering, and long‐term potentiation/depression (LTP/D). Moreover, the fabricated synaptic devices show enhanced nonvolatile characteristics, such as long retention time (≈102 s), high ratio of Gmax/Gmin, high linearity, and reliable cyclic endurance (≈103 pulses). This study presents a new pathway for next‐generation neuromorphic computing by modulating conjugated polymers with side chain control, thereby achieving high‐performance synaptic properties.

Abstract The sequential deposition method assists the vertical phase distribution in the photoactive layer of organic solar cells, enhancing power conversion efficiencies. With this film coating approach, the morphology of both layers can be fine‐tuned with high boiling solvent additives, as frequently applied in one‐step casting films. However, introducing liquid additives can compromise the morphological stability of the devices due to the solvent residuals. Herein, 1,3,5‐tribromobenzene (TBB) with high volatility and low cost, is used as a solid additive in the acceptor solution and combined thermal annealing to regulate the vertical phase in organic solar cells composed of D18‐Cl/L8‐BO. Compared to the control cells, the devices treated with TBB and those that underwent additional thermal processing exhibit increased exciton generation rate, charge carrier mobility, charge carrier lifetime, and reduced bimolecular charge recombination. As a result, the TBB‐treated organic solar cells achieve a champion power conversion efficiency of 18.5% (18.1% averaged), one of the highest efficiencies in binary organic solar cells with open circuit voltage exceeding 900 mV. This study ascribes the advanced device performance to the gradient‐distributed donor‐acceptor concentrations in the vertical direction. The findings provide guidelines for optimizing the morphology of the sequentially deposited top layer to achieve high‐performance organic solar cells.

Abstract Single junction binary all‐small‐molecule (ASM) organic solar cells (OSCs) with power conversion efficiency (PCE) beyond 14% are achieved by using non‐fullerene acceptor Y6 as the electron acceptor, but still lag behind that of polymer OSCs. Herein, an asymmetric Y6‐like acceptor, BTP‐FCl‐FCl, is designed and synthesized to match the recently reported high performance small molecule donor BTR‐Cl, and a record efficiency of 15.3% for single‐junction binary ASM OSCs is achieved. BTP‐FCl‐FCl features a F,Cl disubstitution on the same end group affording locally asymmetric structures, and so has a lower total dipole moment, larger average electronic static potential, and lower distribution disorder than those of the globally asymmetric isomer BTP‐2F‐2Cl, resulting in improved charge generation and extraction. In addition, BTP‐FCl‐FCl based active layer presents more favorable domain size and finer phase separation contributing to the faster charge extraction, longer charge carrier lifetime, and much lower recombination rate. Therefore, compared with BTP‐2F‐2Cl, BTP‐FCl‐FCl based devices provide better performance with FF enhanced from 71.41% to 75.36% and Jsc increased from 22.35 to 24.58 mA cm−2, leading to a higher PCE of 15.3%. The locally asymmetric F, Cl disubstitution on the same end group is a new strategy to achieve high performance ASM OSCs.

Human perception systems are highly refined, relying on an adaptive, plastic, and event-driven network of sensory neurons. Drawing inspiration from Nature, neuromorphic perception systems hold tremendous potential for efficient multisensory signal processing in the physical world; however, the development of an efficient artificial neuron with a widely calibratable spiking range and reduced footprint remains challenging. Here, we report an efficient organic electrochemical neuron (OECN) with reduced footprint (<37 mm2) based on high-performance vertical OECT (vOECT) complementary circuitry enabled by an advanced n-type polymer for balanced p-/n-type vOECT performance. The OECN exhibits outstanding neuronal characteristics, capable of producing spikes with a widely calibratable state-of-the art firing frequency range of 0.130 to 147.1 Hz. Leveraging this capability, we develop a neuromorphic perception system that integrates mechanical sensors with the OECN and integrates them with an artificial synapse for tactile perception. The system successfully encodes tactile stimulations into frequency-dependent spikes, which are further converted into postsynaptic responses. This bioinspired design demonstrates significant potential to advance cyborg and neuromorphic systems, providing them with perceptual capabilities. [ABSTRACT FROM AUTHOR]

The article focuses on achieving ideal transistor characteristics in conjugated polymer semiconductors. The topics discussed include the challenges of achieving ideal transistor behavior in polymer OTFTs, the identification of polymer candidates with low energetic disorder and spatially uniform energetic landscapes, and the demonstration of near-ideal transistor behavior in the semicrystalline polymer PffBT4T-2DT.