Nano-Micro Letters最新文献

Radiative cooling fabric creates a thermally comfortable environment without energy input, providing a sustainable approach to personal thermal management. However, most currently reported fabrics mainly focus on outdoor cooling, ignoring to achieve simultaneous cooling both indoors and outdoors, thereby weakening the overall cooling performance. Herein, a full-scale structure fabric with selective emission properties is constructed for simultaneous indoor and outdoor cooling. The fabric achieves 94% reflectance performance in the sunlight band (0.3–2.5 µm) and 6% in the mid-infrared band (2.5–25 µm), effectively minimizing heat absorption and radiation release obstruction. It also demonstrates 81% radiative emission performance in the atmospheric window band (8–13 µm) and 25% radiative transmission performance in the mid-infrared band (2.5–25 μm), providing 60 and 26 W m⁻² net cooling power outdoors and indoors. In practical applications, the fabric achieves excellent indoor and outdoor human cooling, with temperatures 1.4–5.5 °C lower than typical polydimethylsiloxane film. This work proposes a novel design for the advanced radiative cooling fabric, offering significant potential to realize sustainable personal thermal management.

Emerging two-dimensional (2D) semiconductors are among the most promising materials for ultra-scaled transistors due to their intrinsic atomic-level thickness. As the stacking process advances, the complexity and cost of nanosheet field-effect transistors (NSFETs) and complementary FET (CFET) continue to rise. The 1 nm technology node is going to be based on Si-CFET process according to international roadmap for devices and systems (IRDS) (2022, https://irds.ieee.org/), but not publicly confirmed, indicating that more possibilities still exist. The miniaturization advantage of 2D semiconductors motivates us to explore their potential for reducing process costs while matching the performance of next-generation nodes in terms of area, power consumption and speed. In this study, a comprehensive framework is built. A set of MoS₂ NSFETs were designed and fabricated to extract the key parameters and performances. And then for benchmarking, the sizes of 2D-NSFET are scaled to a extent that both of the Si-CFET and 2D-NSFET have the same average device footprint. Under these conditions, the frequency of ultra-scaled 2D-NSFET is found to improve by 36% at a fixed power consumption. This work verifies the feasibility of replacing silicon-based CFETs of 1 nm node with 2D-NSFETs and proposes a 2D technology solution for 1 nm nodes, i.e., “2D eq 1 nm” nodes. At the same time, thanks to the lower characteristic length of 2D semiconductors, the miniaturized 2D-NSFET achieves a 28% frequency increase at a fixed power consumption. Further, developing a standard cell library, these devices obtain a similar trend in 16-bit RISC-V CPUs. This work quantifies and highlights the advantages of 2D semiconductors in advanced nodes, offering new possibilities for the application of 2D semiconductors in high-speed and low-power integrated circuits.

Composite solid electrolytes (CSEs) are promising for solid-state Li metal batteries but suffer from inferior room-temperature ionic conductivity due to sluggish ion transport and high cost due to expensive active ceramic fillers. Here, a host–guest inversion engineering strategy is proposed to develop superionic CSEs using cost-effective SiO₂ nanoparticles as passive ceramic hosts and poly(vinylidene fluoride-hexafluoropropylene) (PVH) microspheres as polymer guests, forming an unprecedented “polymer guest-in-ceramic host” (i.e., PVH-in-SiO₂) architecture differing from the traditional “ceramic guest-in-polymer host”. The PVH-in-SiO₂ exhibits excellent Li-salt dissociation, achieving high-concentration free Li⁺. Owing to the low diffusion energy barriers and high diffusion coefficient, the free Li⁺ is thermodynamically and kinetically favorable to migrate to and transport at the SiO₂/PVH interfaces. Consequently, the PVH-in-SiO₂ delivers an exceptional ionic conductivity of 1.32 × 10⁻³ S cm⁻¹ at 25 °C (vs. typically 10⁻⁵–10⁻⁴ S cm⁻¹ using high-cost active ceramics), achieved under an ultralow residual solvent content of 2.9 wt% (vs. 8–15 wt% in other CSEs). Additionally, PVH-in-SiO₂ is electrochemically stable with Li anode and various cathodes. Therefore, the PVH-in-SiO₂ demonstrates excellent high-rate cyclability in LiFePO₄|Li full cells (92.9% capacity-retention at 3C after 300 cycles under 25 °C) and outstanding stability with high-mass-loading LiFePO₄ (9.2 mg cm⁻¹) and high-voltage NCM622 (147.1 mAh g⁻¹). Furthermore, we verify the versatility of the host–guest inversion engineering strategy by fabricating Na-ion and K-ion-based PVH-in-SiO₂ CSEs with similarly excellent promotions in ionic conductivity. Our strategy offers a simple, low-cost approach to fabricating superionic CSEs for large-scale application of solid-state Li metal batteries and beyond.

Directly correlating the morphology and composition of interfacial water is vital not only for studying water icing under critical conditions but also for understanding the role of protein–water interactions in bio-relevant systems. In this study, we present a model system to study two-dimensional (2D) water layers under ambient conditions by using self-assembled monolayers (SAMs) supporting the physisorption of the Cytochrome C (Cyt C) protein layer. We observed that the 2D island-like water layers were uniformly distributed on the SAMs as characterized by atomic force microscopy, and their composition was confirmed by nano-atomic force microscopy-infrared spectroscopy and Raman spectroscopy. In addition, these 2D flakes could grow under high-humidity conditions or melt upon the introduction of a heat source. The formation of these flakes is attributed to the activation energy for water desorption from the Cyt C being nearly twofold high than that from the SAMs. Our results provide a new and effective method for further understanding the water–protein interactions.

Fiber-shaped energy storage devices (FSESDs) with exceptional flexibility for wearable power sources should be applied with solid electrolytes over liquid electrolytes due to short circuits and leakage issue during deformation. Among the solid options, polymer electrolytes are particularly preferred due to their robustness and flexibility, although their low ionic conductivity remains a significant challenge. Here, we present a redox polymer electrolyte (HT_RPE) with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (HT) as a multi-functional additive. HT acts as a plasticizer that transforms the glassy state into the rubbery state for improved chain mobility and provides distinctive ion conduction pathway by the self-exchange reaction between radical and oxidized species. These synergetic effects lead to high ionic conductivity (73.5 mS cm⁻¹) based on a lower activation energy of 0.13 eV than other redox additives. Moreover, HT_RPE with a pseudocapacitive characteristic by HT enables an outstanding electrochemical performance of the symmetric FSESDs using carbon-based fiber electrodes (energy density of 25.4 W h kg⁻¹ at a power density of 25,000 W kg⁻¹) without typical active materials, along with excellent stability (capacitance retention of 91.2% after 8,000 bending cycles). This work highlights a versatile HT_RPE that utilizes the unique functionality of HT for both the high ionic conductivity and improved energy storage capability, providing a promising pathway for next-generation flexible energy storage devices.

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