The exponentially increasing heat generation in electronic devices, induced by high power density and miniaturization, has become a dominant issue that affects carbon footprint, cost, performance, reliability, and lifespan. Liquid metals (LMs) with high thermal conductivity are promising candidates for effective thermal management yet are facing pump-out and surface-spreading issues. Confinement in the form of metallic particles can address these problems, but apparent alloying processes elevate the LM melting point, leading to severely deteriorated stability. Here, we propose a facile and sustainable approach to address these challenges by using a biogenic supramolecular network as an effective diffusion barrier at copper particle-LM (EGaIn/Cu@TA) interfaces to achieve superior thermal conduction. The supramolecular network promotes LM stability by reducing unfavorable alloying and fluidity transition. The EGaIn/Cu@TA exhibits a record-high metallic-mediated thermal conductivity (66.1 W m-1 K-1) and fluidic stability. Moreover, mechanistic studies suggest the enhanced heat flow path after the incorporation of copper particles, generating heat dissipation suitable for computer central processing units, exceeding that of commercial silicone. Our results highlight the prospects of renewable macromolecules isolated from biomass for the rational design of nanointerfaces based on metallic particles and LM, paving a new and sustainable avenue for high-performance thermal management.
Two-dimensional transition metal dichalcogenides (TMDs) are needed in high-performance piezoresistive sensors due to their strong strain-induced bandgap modification and thereby large gauge factors. However, integrating a conventional high-temperature chemical vapor deposition (CVD)-grown TMD with a flexible substrate necessitates a transfer process that inevitably degrades the sensing properties of the TMDs and increases the overall fabrication complexity. We present a high-performance piezoresistive strain sensor that employs large-area PdSe2 films grown directly on polyimide (PI) substrates via plasma-assisted selenization of a sputtered Pd film. The reliable strain transfer from the substrate to the PdSe2 film ensures an outstanding strain-sensing capability of the sensor. Specifically, the sensors have a gauge factor of up to -315 ± 2.1, a response time under 25 ms, a detection limit of 8 × 10-6, and an exceptional stability of over 104 loading-unloading cycles. By attaching the sensors to the skin surface, we demonstrate their application for measuring physiological parameters in health care monitoring, including motion, voice, and arterial pulse vibration. Furthermore, using the PdSe2 film sensor combined with deep learning technology, we achieved intelligent recognition of artery temperature from arterial pulse signals with only a 2% difference between predicted and actual temperatures. The excellent sensing performance, together with the advantages of low-temperature fabrication and simple device structure, make the PdSe2 film sensor promising for wearable electronics and health care sensing systems.
Aqueous zinc (Zn) ion batteries (AZIBs) are regarded as one of the promising candidates for next-generation electrochemical energy storage systems due to their low cost, high safety, and environmental friendliness. However, the commercialization of AZIBs has been severely restricted by the growth of dendrite at the Zn metal anode. Tailoring the planar-structured Zn anodes into three-dimensional (3D) structures has proven to be an effective way to modulate the plating/stripping behavior of Zn anodes, resulting in the suppression of dendrite formation. This review provides an up-to-date review of 3D structured Zn metal anodes, including working principles, design, current status, and future prospects. We aim to give the readers a comprehensive understanding of 3D-structured Zn anodes and their effective usage to enhance AZIB performance.
Metal-semiconductor contacts are crucial components in semiconductor devices. Ultrathin two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated circuits. However, their performance is often degraded by conventional metal deposition, which results in a high barrier due to chemical disorder and Fermi-level pinning (FLP). Although, transferring electrodes can address these issues, they are limited in achieving universal transfer of full-class metals due to strong adhesion between pre-deposited metals and substrates. Here, we propose a nanobelt-assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of electrodes. Our contacts obey the Schottky-Mott rule and exhibit a FLP of S = 0.99. Both the electron and hole contacts show record-low Schottky barriers of 4.2 and 11.2 meV, respectively. As a demonstration, we construct a doping-free WSe2 inverter with these high-performance contacts, which exhibits a static power consumption of only 58 pW. This strategy provides a universal method of electrode preparation for building high-performance post-Moore electronic devices.
Electrochemical water splitting represents a promising technology for green hydrogen production. To design advanced electrocatalysts, it is crucial to identify their active sites and interpret the relationship between their structures and performance. Materials extensively studied as electrocatalysts include noble-metal-based (e.g., Ru, Ir, and Pt) and non-noble-metal-based (e.g., 3d transition metals) compounds. Recently, advancements in characterization techniques and theoretical calculations have revealed novel and unusual active sites. The present review highlights the latest achievements in the discovery and identification of various unconventional active sites for electrochemical water splitting, with a focus on state-of-the-art strategies for determining true active sites and establishing structure-activity relationships. Furthermore, we discuss the remaining challenges and future perspectives for the development of next-generation electrocatalysts with unusual active sites. By presenting a fresh perspective on the unconventional reaction sites involved in electrochemical water splitting, this review aims to provide valuable guidance for the future study of electrocatalysts in industrial applications.
Lead sulfide (PbS) colloidal quantum dot (CQD) photodiodes integrated with silicon-based readout integrated circuits (ROICs) offer a promising solution for the next-generation short-wave infrared (SWIR) imaging technology. Despite their potential, large-size CQD photodiodes pose a challenge due to high dark currents resulting from surface states on non-passivated (100) facets and trap states generated by CQD fusion. In this work, we present a novel approach to address this issue by introducing double-ended ligands that supplementally passivate (100) facets of halide-capped large-size CQDs, leading to suppressed bandtail states and reduced defect concentration. Our results demonstrate that the dark current density is highly suppressed by about an order of magnitude to 9.6 nA cm-2 at -10 mV, which is among the lowest reported for PbS CQD photodiodes. Furthermore, the performance of the photodiodes is exemplary, yielding an external quantum efficiency of 50.8% (which corresponds to a responsivity of 0.532 A W-1) and a specific detectivity of 2.5 × 1012 Jones at 1300 nm. By integrating CQD photodiodes with CMOS ROICs, the CQD imager provides high-resolution (640 × 512) SWIR imaging for infrared penetration and material discrimination.
Intelligent applications, with tactile sensors at their core, represent significant advancement in the field of artificial intelligence. However, achieving perception abilities in tactile sensors that match or exceed human skin remains a formidable challenge. Consequently, the design and implementation of hierarchical structural materials are considered the optimal solution to this challenge. In contrast to conventional methods, such as complicated lithography and three-dimensional printing, the cost-effective and scalable nature of advanced solution-synthesis methods makes them ideal for preparing diverse tactile sensors with hierarchical structural materials. However, the process and applicability of advanced solution synthesis methods have yet to form a seamless system. Accordingly, the development and intellectualization of tactile sensors based on advanced solution synthesis methods are still in their early stages, and require a comprehensive and systematic review to usher in progress. This study delves into the advantages and disadvantages of various advanced solution synthesis methods, providing detailed insights. Furthermore, the positive effects of hierarchical structural materials constructed using these methods in tactile sensors and their intelligent applications are also discussed in depth. Finally, the challenges and future opportunities faced by this emerging field are summarized.
Narrowband photodetectors conventionally rely on optical structure design or bandpass filters to achieve the narrowband regime. Recently, a strategy for filterless narrowband photoresponse based on the charge collection narrowing (CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy for constructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). By manipulating the ion migration with external stimuli such as illumination, temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response. Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drift technique, we discover two critical mechanisms behind our BMN strategy: the extension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transport layer. Our findings offer a case for harnessing the often-annoying ion migration for developing advanced narrowband PPDs.