Bias-dependent photoresponse of Td-WTe2grown by Chemical Vapor Deposition.

The type-II Weyl semimetal Td-WTe2is one of the wonder materials for high-performance optoelectronic devices. We report the self-powered Td-WTe2photodetectors and their bias-dependent photoresponse in the visible region (405 nm, 520 nm, 638 nm) driven by the bulk photovoltaic effect (BPE). The device shows the responsivity of 15.8 mAW-1and detectivity of 5.2×109Jones at 520 nm. Besides, the response time of the WTe2photodetector shows a strong bias-voltage dependent property. This work offers a physical reference for understanding the photoresponse process of Td-WTe2photodetectors.

Precise Atomic Structure Regulation of Single-Atom Platinum Catalysts toward Highly Efficient Hydrogen Evolution Reaction.

Noble metal single-atom-catalysts (SACs) have demonstrated significant potential to improve atom utilization efficiency and catalytic activity for hydrogen evolution reaction (HER). However, challenges still remain in rationally modulating active sites and catalytic activities of SACs, which often results in sluggish kinetics and poor stability, especially in neutral/alkaline media. Herein, precise construction of Pt single atoms anchored on edge of 2D layered Ni(OH)2 (Pt-Ni(OH)2-E) is achieved utilizing in situ electrodeposition. Compared to the single-atom Pt catalysts anchored on the basal plane of Ni(OH)2 (Pt-Ni(OH)2-BP), the Pt-Ni(OH)2-E possesses superior electron affinity and high intrinsic catalytic activity, which favors the strong adsorption and rapid dissociation toward water molecules. As a result, the Pt-Ni(OH)2-E catalyst requires low overpotentials of 21 and 34 mV at 10 mA cm-2 in alkaline and neutral conditions, respectively. Specifically, it shows the high mass activity of 23.6 A mg-1 for Pt at the overpotential of 100 mV, outperforming the reported catalysts and commercial Pt/C. This work provides new insights into the rational design of active sites for preparing high-performance SACs.

Meta-analysis of Huangqi (Astragalus membranaceus) and Chinese Yam (Rhizoma Dioscoreae) for Diabetic Nephropathy.

Context: Diabetic nephropathy (DN), also known as diabetic kidney disease (DKD), has caused enormous economic pressure and serious health problems worldwide. TCM practitioners commonly use a combination of Astragalus membranaceus (A. membranaceus) and Rhizoma Dioscoreae (R. Dioscoreae) in the treatment of DN. Research is still lacking on the therapeutic effects of TCM for DN. Objective: The systematic review and meta-analysis intended to evaluate whether the combination of A. membranaceus and R. Dioscoreae together with Western medicine can provide better efficacy against DN than treatment with traditional Western medicine alone, to provide a clinical medical basis for the use of the TCM combination. Design: The research team performed a performed a systematic narrative review by searching the Web of Science, Science Direct, Pubmed, China National Knowledge Infrastructure (CNKI), VIP, Wanfang, Chinese Science and Technology Journal Database, and Biomedical Literature Chinese Database from databases' inceptions to May 2023. The team used the keywords astragalus and yam, diabetic nephropathy, antidiabetic, and 24-h urinary protein. Setting: The review and meta-analysis occurred at Jiangxi Hospital of Integrated Traditional China and Western Medicine in Nanchang, Jiangxi, China. Intervention: To perform a subgroup analysis, the research team divided the studies into two groups based on the TCM treatment course, with one subgroup receiving treatment for ≤4 weeks and the second receiving treatment for >4 weeks, to judge whether a time-dependence existed for the effects of the TCM combination on UP. Outcome Measure: All studies used 24-h urinary protein (UP) as the outcome measure. Results: In all studies, all heterogeneous (P < .01, I2 = 94%, the intervention groups had a significantly greater reduction in 24-h UP than the control groups did (P < .05). The heterogeneity for a treatment course of ≤4 weeks was P < .01, I2 = 97%, and for a course of >4 weeks was P < .01, I2 = 87%. For both ≤4 weeks and >4 weeks, the intervention groups had a significantly greater reduction in 24-h UP than the control groups did, with P < .01 and P < .01, respectively. The protein effect wasn't time dependent. Conclusions: A. membranaceus and R. Dioscoreae can significantly reduce UP production, and inhibition of UP wasn't time-dependent.

A polar-switchable and controllable negative phototransistor for information encryption.

Anomalous negative phototransistors have emerged as a distinct research area, characterized by a decrease in channel current under light illumination. Recently, their potential applications have been expanded beyond photodetection. Despite the considerable attention given to negative phototransistors, negative photoconductance (NPC) in particular remains relatively unexplored, with limited research advancements as compared to well-established positive phototransistors. In this study, we designed ferroelectric field-effect transistors (FeFETs) based on the WSe2/CIPS van der Waals (vdW) vertical heterostructures with a buried-gated architecture. The transistor exhibits NPC and positive photoconductance (PPC), demonstrating the significant role of ferroelectric polarization in the distinctive photoresponse. The observed inverse photoconductance can be attributed to the dynamic switching of ferroelectric polarization and interfacial charge transfer processes, which have been investigated experimentally and theoretically using Density Functional Theory (DFT). The unique phenomena enable the coexistence of controllable and polarity-switchable PPC and NPC. The novel feature holds tremendous potential for applications in optical encryption, where the specific gate voltages and light can serve as universal keys to achieve modulation of conductivity. The ability to manipulate conductivity in response to optical stimuli opens up new avenues for developing secure communication systems and data storage technologies. Harnessing this feature enables the design of advanced encryption schemes that rely on the unique properties of our material system. The study not only advances the development of NPC but also paves the way for more robust and efficient methods of optical encryption, ensuring the confidentiality and integrity of critical information in various domains, including data transmission, and information security.

Microstructure characterization, phase transition, and device application of phase-change memory materials.

Phase-change memory (PCM), recently developed as the storage-class memory in a computer system, is a new non-volatile memory technology. In addition, the applications of PCM in a non-von Neumann computing, such as neuromorphic computing and in-memory computing, are being investigated. Although PCM-based devices have been extensively studied, several concerns regarding the electrical, thermal, and structural dynamics of phase-change devices remain. In this article, aiming at PCM devices, a comprehensive review of PCM materials is provided, including the primary PCM device mechanics that underpin read and write operations, physics-based modeling initiatives and experimental characterization of the many features examined in nanoscale PCM devices. Finally, this review will propose a prognosis on a few unsolved challenges and highlight research areas of further investigation.

Ultra-Stable, Endurable, and Flexible Sb2TexSe3-x Phase Change Devices for Memory Application and Wearable Electronics.

Flexible memory and wearable electronics represent an emerging technology, thanks to their reliability, compatibility, and superior performance. Here, an Sb2TexSe3-x (STSe) phase change material was grown on flexible mica, which not only exhibited superior nature in thermal stability for phase change memory application but also revealed novel function performance in wearable electronics, thanks to its excellent mechanical reliability and endurance. The thermal stability of Sb2Te3 was improved obviously with the crystallization temperature elevated 60 K after Se doping, for the enhanced charge localization and stronger bonding energy, which was validated by the Vienna ab initio simulation package calculations. Based on the ultra-stability of STSe, the STSe-based phase change memory shows 65 000 reversible phase change ability. Moreover, the assembled flexible device can show real-time monitoring and recoverability response in sensing human activities in different parts of the body, which proves its effective reusability and potential as wearable electronics. Most importantly, the STSe device presents remarkable working reliability, reflected by excellent endurance over 100 s and long retention over 100 h. These results paved a novel way to utilize STSe phase change materials for flexible memory and wearable electronics with extreme thermal and mechanical stability and brilliant performance.