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As the best-performing materials for thermoelectric cooling, Bi₂Te₃-based alloys have long attracted attention to optimizing the room-temperature performance of Bi₂Te₃ for both power generation and refrigeration applications. This focus leads to less emphasis and fewer reports on the cooling capability below room temperature. Given that the optimal carrier concentration (n_opt) for maximizing the cooling power is highly temperature dependent, roughly following the relationship n_opt∝T^3/2, lowering the carrier concentration is essential to improve the cooling capability at cryogenic temperatures. Taking p-type Bi_0.5Sb_1.5Te₃ as an example, careful control of doping in this work enables a reduction in carrier concentration to 1.7 × 10¹⁹ cm⁻³ from its optimum at 300 K of 3.4 × 10¹⁹ cm⁻³. This work successfully shifts the temperature at which the thermoelectric figure of merit (zT) peaks down to 315 K, with an average zT as high as 0.8 from 180 to 300 K. Further pairing with commercial n-type Bi₂Te₃-alloys, the cooling device realizes a temperature drop as large as 68 K from 300 K and 24 K from 180 K, demonstrating the extended cooling capability of thermoelectric coolers at cryogenic temperatures.

Physical reservoir computing (PRC) offers an effective computing paradigm for spatiotemporal information processing with low training costs. Achieving controllable regulation over the temporal dynamics of devices to meet the computational demands of each physical layer is a key challenge for realizing high-performance PRC chips. Here, we proposed a homogeneously integrated all-PRC with tunable temporal dynamics. Utilizing the modulation effect of oxygen vacancies on the energy barrier of the pentacene/ZnO interface, short-term memory, and long-term memory switching characteristics have been achieved within the same device structure. Furthermore, by altering the gate voltage, the reservoir exhibited a broad range ratio of temporal characteristics (>10²), which provides the potential to map information with different temporal characteristics. Inspired by the process of encoding and reconstructing spatiotemporal information in the human visual system, a biomimetic obstacle recognition system has been constructed to assist visually impaired individuals in walking, demonstrating excellent accuracy in obstacle types (100%) and distances (97.2%) recognition. This work offers a promising avenue for the development of an integrated PRC system with multi-timescale information processing capability.

Multiresonance organoboron helicenes are promising narrowband circularly polarized luminescence (CPL) emitters, which, however, still face formidable challenges to balance a large luminescence dissymmetry factor (g_lum) and a high luminescence efficiency. Here, two pairs of organoboron enantiomers (P/M-BN[8]H-ICz and P/M-BN[8]H-BO) with the same hetero[8]helicene geometric structures are developed through polycyclization decoration. We find that it is the helicity of helicene electronic structures rather than the geometrical one that determines the molecular dissymmetry property as a larger electronic helicity could enhance the electron-orbital coupling of the helicene structure. Therefore, P/M-BN[8]H-BO who possesses a hetero[8]helicene electronic structure realizes a nearly one-order-of-magnitude higher g_lum (+2.75/−2.52 × 10⁻³) and a higher photoluminescence quantum yield (PLQY) of 99% compared with P/M-BN[8]H-ICz bearing only a hetero[6]helicene electronic distribution structure (g_lum of only +2.41/−2.37 × 10⁻⁴ and PLQY of 95%). Moreover, BN[8]H-BO exhibits a narrowband green emission peaking at 538 nm with a full-width at half-maxima of merely 34 nm, narrower than most multiresonance CPL helicenes. The corresponding organic light-emitting diodes simultaneously realize a high external quantum efficiency of 31.7%, an electroluminescence dissymmetry factors (g_EL) of +5.23/−5.07 × 10⁻³, and an extremely long LT95 (time to 95% of the initial luminance) of over 731 h at an initial luminance of 1000 cd m^–2.

Luminescence in organics that lasts for seconds to a few hours after light excitation has been reported recently, showcasing significant application potentials in flexible electronics and bioimaging. In contrast, long-lasting luminescence that can be electrically excited, whether in organics or inorganics, is much rarer and often less efficient. In this study, we report persistent luminescence (PersL) in organic light-emitting diodes (OLEDs) that lasts over 100 s and an energy storage effect beyond 60 min after charging with a direct-current electric field. Thermoluminescence studies reveal that the PersL in OLEDs is induced by traps formed in a host-guest molecular system serving as an emission layer (EML) with a trap depth of approximately 0.24 eV, consistent with the results from the same EML materials under light irradiation. Integrating results from electronic spin resonance, and density functional theory calculations, we propose a model delineating the charge carrier migration responsible for the trap-induced PersL in OLEDs. This study on trap-induced PersL in OLEDs may deepen our understanding of the luminescence mechanism in organic semiconductors and pave the way for expanding their applications in optoelectronics, energy storage and biological detection technologies.

The cover image showcases the application of a cutting-edge two-dimensional material in the electrocatalytic direct seawater splitting process. The central figure depicts an electrode made from this two-dimensional material, featuring easily accessible active sites that symbolize its high efficiency in seawater splitting. The surrounding gradient of green indicates the flow of seawater, while the light spheres around the electrode represent the bubbles of water molecules. The light blue and orange spheres signify the hydrogen and oxygen produced during the electrocatalytic process. The overall design emphasizes the crucial role of two-dimensional materials in advancing seawater splitting technology, suggesting potential for future sustainable energy production.

Lithium batteries are becoming increasingly vital thanks to electric vehicles and large-scale energy storage. Carbon materials have been applied in battery cathode, anode, electrolyte, and separator to enhance the electrochemical performance of rechargeable lithium batteries. Their functions cover lithium storage, electrochemical catalysis, electrode protection, charge conduction, and so on. To rationally implement carbon materials, their properties and interactions with other battery materials have been probed by theoretical models, namely density functional theory and molecular dynamics. This review summarizes the use of theoretical models to guide the employment of carbon materials in advanced lithium batteries, providing critical information difficult or impossible to obtain from experiments, including lithiophilicity, energy barriers, coordination structures, and species distribution at interfaces. Carbon materials under discussion include zero-dimensional fullerenes and capsules, one-dimensional nanotubes and nanoribbons, two-dimensional graphene, and three-dimensional graphite and amorphous carbon, as well as their derivatives. Their electronic conductivities are explored, followed by applications in cathode and anode performance. While the role of theoretical models is emphasized, experimental data are also touched upon to clarify background information and show the effectiveness of strategies. Evidently, carbon materials prove promising in achieving superior energy density, rate performance, and cycle life, especially when informed by theoretical endeavors.

All-perovskite tandem solar cells have garnered considerable attention because of their potential to outperform single-junction cells. However, charge recombination losses within narrow-bandgap (NBG) perovskite subcells hamper the advancement of this technology. Herein, we introduce a lithium salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), for modifying NBG perovskites. Interestingly, LiTFSI bifunctionally passivates the surface and bulk of NBG by dissociating into Li⁺ and TFSI⁻ ions. We found that TFSI⁻ passivates halide vacancies on the perovskite surface, reducing nonradiative recombination, while Li⁺ acts as an interstitial n-type dopant, mitigating the defects of NBG perovskites and potentially suppressing halide migration. Furthermore, the underlying mechanism of LiTFSI passivation was investigated through the density functional theory calculations. Accordingly, LiTFSI facilitates charge extraction and extends the charge carrier lifetime, resulting in an NBG device with power conversion efficiency (PCE) of 22.04% (certified PCE of 21.42%) and an exceptional fill factor of 81.92%. This enables the fabrication of all-perovskite tandem solar cells with PCEs of 27.47% and 26.27% for aperture areas of 0.0935 and 1.02 cm², respectively.

Multicolor photodetection, essential for applications in infrared imaging, environmental monitoring, and spectral analysis, is often limited by the narrow bandgaps of conventional materials, which struggle with speed, sensitivity, and room-temperature operation. We address these issues with a multicolor uncooled photodetector based on an asymmetric Au/SnS/Gr vertical heterojunction with inversion-symmetry breaking. This design utilizes the complementary bandgaps of SnS and graphene to enhance the efficiency of carriers' transport through consistently oriented built-in electric fields, achieving significant advancements in directional photoresponse. The device demonstrates highly sensitive photoelectric detection performance, such as a responsivity (R) of 55.4–89.7 A W^–1 with rapid response times of approximately 104 μs, and exceptional detectivity (D*) of 2.38 × 10¹⁰ Jones ~8.19 × 10¹³ Jones from visible (520 nm) to infrared (2000 nm) light, making it suitable for applications demanding an imaging resolution of ~0.5 mm. Additionally, the comparative analysis reveals that the asymmetric vertical heterojunction outperforms its counterparts, exhibiting approximately 9-fold the photoresponse of symmetric vertical heterojunction and almost 100-fold that of symmetric horizontal heterojunction. This highly sensitive multicolor detector holds significant promise for applications in advanced versatile object detection and imaging recognition systems.

Organic memristors, integrating chemically designed resistive switching and mechanical flexibility, present promising hardware opportunities for neuromorphic computing, particularly in the development of next-generation wearable artificial intelligence devices. However, challenges persist in achieving high yield, controllable switching, and multi-modal information processing. In this study, we introduce an efficient distribution of conversion bridges (EDCB) strategy by dispersing organic semiconductor (poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene], PBTTT) in elastomer (polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene, SEBS). This innovative approach results in memristors with exceptional yield, high stretchability, and reliable switching performance. By fine-tuning the semiconductor content, we shift the primary charge carriers from ions to electrons, realizing modulable non-volatile, and volatile duo-mode memristors. This advancement enables multi-modal signal processing at distinct operational mechanisms—non-volatile mode for image recognition in convolutional neural networks (CNNs) and volatile mode for dynamic classification and prediction in reservoir computing (RC). A fully analog RC hardware system is further demonstrated by integrating the distinct volatile and non-volatile modes of the EDCB-based memristor into the dynamic neuron network and the linear regression layer of the RC respectively, achieving high accuracy in online arrhythmia detection tasks. Our work paves the way for high-yield organic memristors with mechanical flexibility, advancing efficient multi-mode neuromorphic computing within a unified memristor system integrating volatile and non-volatile functionalities.

Currently, conventional organic liquid electrolytes (OLEs) are the main limiting factor for the next generation of high-energy lithium batteries. There is growing interest in inorganic solid-state electrolytes (ISEs). However, ISEs still face various challenges in practical applications, particularly at the interface between ISE and the electrode, which significantly affects the performance of solid-state batteries (SSBs). In recent decades, atomic and molecular layer deposition (ALD and MLD) techniques, widely used to manipulate interface properties and construct novel electrode structures, have emerged as promising strategies to address the interface challenges faced by ISEs. This review focuses on the latest developments and applications of ALD/MLD technology in SSBs, including interface modification of cathodes and lithium metal anodes. From the perspective of interface strategy mechanism, we present experimental progress and computational simulations related to interface chemistry and electrochemical stability in thermodynamic contents. In addition, this article explores the future direction and prospects for ALD/MLD in dynamic stability engineering of interfaces SSBs.