Electron最新文献

V-pits have been intensively studied for their role in light-emitting diodes (LEDs). The coverage of V-pits in InGaN/GaN multi-quantum wells (MQWs) is critical for suppressing leakage path through electron blocking layer (EBL). In this study, we have investigated the coverage of V-pits in green mini-LEDs modulated via growth parameters optimization and systematically analyzed the characteristics of the photoelectric properties associated with V-pits coverage on device. Elevated temperatures and pressures result in enhanced adatoms migration, which can achieve a coverage up to 98.8% of V-pits, improving the crystal quality due to stable surface. Electrical characterization reveals that although high-coverage devices exhibit suppressed leakage current, their peak external quantum efficiency (EQE) decreases, more seriously spectral blue shift and operating voltage increase due to compromised hole transport uniformity. Intriguingly, intermediate-coverage samples demonstrate superior breakdown voltage characteristics. Current–voltage curve analysis shows the ideality factor increases from 1.8 to 2.5 with improved coverage, indicating aggravated Shockley–Read–Hall (SRH) recombination with covered V-pits.

Photoelectrochemical (PEC) water splitting presents a promising route for sustainable hydrogen production, yet the efficiency of metal oxide photoanodes remains limited by suboptimal light absorption, charge carrier recombination, and sluggish surface reaction kinetics. This review critically examines the strategic engineering of oxygen vacancies (OVs) as a powerful tool for overcoming these intrinsic limitations. We systematically analyze established methodologies for the deliberate introduction and modulation of OVs in metal oxides, including techniques such as the hydrothermal method, thermal treatment, chemical reduction, plasma processing, elemental doping, and microwave heating. Furthermore, we critically evaluate the applicability, strengths, and limitations of key characterization techniques for detecting and quantifying OVs. Crucially, the review delves into the profound mechanistic impacts of OVs on the PEC process chain: Their roles in tailoring electronic band structures to alter the photoelectrochemical properties of metal oxide photoanodes, thereby enhancing visible light absorption, acting as shallow donors to improve charge carrier density, functioning as electron traps to suppress bulk recombination, and modifying surface states to accelerate the oxygen evolution reaction. We also present detailed case studies focusing on five prominent photoanode materials: TiO₂, α-Fe₂O₃, BiVO₄, WO₃, and ZnFe₂O₄. This review elucidates the specific roles and operational principles of OVs within these materials and summarizes the intrinsic relationship among OV generation, characterization, and functional enhancement, providing valuable insights for the rational design of OV-engineered photoanodes toward efficient solar fuel production.

Optically responsive composite materials hold significant promise for in vivo diagnostics and targeted therapies. Rare-earth-doped upconversion nanoparticles (UCNPs), renowned for their unique luminescence properties, large anti-Stokes shift, excellent biocompatibility, and deep tissue penetration, have emerged as highly promising candidates for advanced phototherapy in biological systems. This review first explores the fundamental mechanisms of upconversion luminescence, as well as synthesis, surface modification, and design strategies to brighten upconversion. It then highlights recent advances and key applications of UCNPs in biological therapy, including upconversion-mediated phototherapy, multimodal therapeutic approaches, and image-guided therapy and surgery. Finally, it discusses the current challenges and opportunities in both fundamental research and clinical translation, providing theoretical insights and practical guidance to support the broader application of UCNPs in biological therapy and clinical medicine.

Solid-state lithium-metal batteries based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVH) are frequently proposed to address the detrimental safety issue of conventional lithium-ion batteries by eliminating the use of flammable solvents, but still face a key challenge: low capacity and sluggish charge/discharge rate due to the intrinsic large-gradient Li⁺ distribution across the ionically-inert PVH matrix. Herein, Te vacancies in form of Bi₂Te_3−x are proposed to polarize the PVH unit to realize efficient decoupling of lithium salts at the atomic level in PVH-based solid polymeric electrolyte. Te vacancies in the PVH electrolyte doped with Bi₂Te_3−x (PVBT) induce a high-throughput and homogenous Li⁺ flow within the PVH matrices and near the Li metal. Theoretical calculations show that Te vacancies own high adsorption energy with bis(trifluoromethanesulfonyl)imide anions (TFSI⁻), repulsive effect on Li⁺, and localized electron distribution, giving rise to a lithium-ion concentration gradient of 30 mol m⁻³, the smallest among the PVH-based inorganic/organic composite electrolytes. Consequently, the polarized electrolyte owns an unprecedented high-rate battery capacity of 114 mAh g⁻¹ at ∼700 mA g⁻¹ and also superior capacity performances with a cathode loading of 12 mg cm⁻², outperforming the state-of-art PVH-based inorganic/organic composite electrolytes in Li||LiFePO₄ battery. The work demonstrates an efficient strategy for achieving fast Li⁺ diffusion dynamics across polymeric matrices of classic solid-state electrolytes.

M₂ phase vanadium dioxide (VO₂(M₂)) is an intermediate polymorph phase during the reversible phase transition from VO₂(M₁) to VO₂(R), which can be stabilized at room temperature by doping or introducing strain in the film. In this study, we provide a simple and scalable preparation of VO₂(M₂) nanorods on TiO₂ nanoparticles decorated flexible glass fiber cloth (GFC) by hydrothermal and subsequent annealing process. Because of the interfacial strain between TiO₂ and VO₂, M₂ phase VO₂ nanorods were successfully fabricated and verified. The resultant VO₂(M₂)/GFC composite demonstrates a remarkable resistance change (∼3.4 × 10⁴) across the phase transition, which is superior to the films prepared by vacuum chamber-based techniques. Meanwhile, it also demonstrates 13.1 times enhanced electromagnetic shielding efficiency and favorable emissivity modulation capability. The flexible and scalable preparation of VO₂(M₂) will broaden the promising applications of the material in both optical and electronic devices.

The study (DOI: 10.1002/elt2.70006) offers a systematic analysis of the structural, electronic, and surface properties of NiO using first-principles density functional theory (DFT) calculations to explore their impact on supercapacitor performance. In this article, the authors utilize DFT to calculate quantum capacitance and investigate how lattice strain affects key parameters such as the electronic band structure, density of states, quantum capacitance, and the adsorption energies of alkali metals. These insights provide a theoretical foundation for optimizing NiO-based materials for energy storage applications.

The cover (DOI: 10.1002/elt2.77) features a dark blue-to-black gradient background, evoking a futuristic aesthetic. Central nanowires divide the composition into three sections, representing the key frontiers of flexible sensing technology: wearable electronics, brain-computer interfaces, and artificial skin. The upper-left and upper-right regions symbolize the convergence of biological and electronic domains. This design visually underscores the broad applications of nanowire-based flexible sensing systems across these three cutting-edge fields, highlighting their transformative potential in next-generation bioelectronics.

This study presents an analysis of the structural, electronic, and surface properties of NiO using first-principles density functional theory (DFT) calculations. The investigation focuses on three lattice parameters (a = 4.23 Å, 4.187 Å, and 4.183 Å) to explore how lattice strain influences the electronic band structure, density of states (DOS), quantum capacitance (QC), and adsorption energies of alkali metals (Li, Na, K) on the NiO [001] and [111] planes. The study reveals that a decrease in the lattice parameter leads to a reduction in the band gap (from 2.28 to 2.19 eV). The adsorption energies demonstrate a strong surface reactivity, with Li showing the highest affinity for the NiO [001] surface and Na exhibiting the highest adsorption energy on the more reactive NiO [111] surface. The QC analysis demonstrated notable enhancements following alkali metal adsorption, with Li on the NiO [001] surface exhibiting a QC of 38.9 μF/cm² at a = 4.23 Å, whereas Na on the NiO [111] surface achieved a QC of 32.7 μF/cm² at a = 4.187 Å. These findings underscore the critical role of lattice strain and surface orientation in modulating the electrochemical performance of NiO, with potential applications in catalysis, energy storage, and electronic devices.

Plastic products have become ubiquitous in our daily lives due to their low cost, durability, and portability. However, the excessive usage of plastics, coupled with inadequate management of post-consumer plastics, inevitably results in a waste of carbon resources and severe environmental issues. In response, photocatalytic conversion of plastic waste into value-added chemicals directly using solar energy has emerged as a sustainable and promising strategy under mild conditions. This review first examined the advantages and limitations of photocatalysis compared to traditional plastic processing methods, including landfill, mechanical recycling, incineration, and thermocatalysis. Subsequently, the effect of pretreatment procedures and photocatalyst selection on solar-to-chemical conversion efficiency was systematically analyzed. Finally, research directions and future prospects were proposed to further advance the photoconversion of plastics into value-added chemicals.

A NASICON-type Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) cathode material was successfully synthesized using a sand grinding-spray drying method. Different doping strategies can impart distinct modifications to materials, with surface Mn-rich doping (SD) being particularly effective. On one hand, the surface enrichment layer can effectively mitigate the volumetric fluctuations of particles, thereby reducing the internal stress and enhancing the cyclic stability. More importantly, the enrichment of the Mn in the particle surface layer provides an increased number of free electrons. This elevates the local electron concentration within the material, fosters greater overlap in the wave functions of electrons, and strengthens the interactions between electrons. The higher energy state of electrons due to increased transition propensity enhances the material's electronic conductivity. As a consequence, the band gap of SD material has decreased from 0.72 eV to 0.45 eV, and the electronic conductivity has increased from 6.0 μS·cm⁻¹ to 21.8 μS·cm⁻¹. The as-optimized SD sample displays both outstanding rate performance (110.8 mAh·g⁻¹ and 99.0 mAh·g⁻¹ at 0.1 C and 5 C, respectively) and excellent cycling stability (88.7% of capacity retention after 1500 cycles at 1 C). The study highlights that the choice of doping methods is equally crucial for the performance of NFPP materials.