The chemical instability of semimetallic transition metal dichalcogenides (TMDs) under ambient conditions poses a major challenge for their integration into spintronic and quantum devices. Here, we establish a quantitative framework to elucidate their oxidation mechanism by combining photoelectron spectroscopy with defect engineering via controlled ion irradiation. Freshly cleaved and defect-enriched Td-WTe2 single crystals were exposed to air at controlled temperatures, enabling direct evaluation of oxidation kinetics by monitoring the time evolution of the oxide-related X-ray photoelectron signal. The introduction of up to ∼4% concentration of Te vacancies by ion sputtering leads to only moderate enhancement of the surface oxidation rate (by a factor of ∼2-3), despite pronounced modifications of the surface electronic structure revealed by angle-resolved photoelectron spectroscopy. Arrhenius model-based analysis indicates that the apparent activation energy for oxidation (∼0.11 eV) remains essentially unaffected following the ∼4% defect generation. Notably, theoretical calculations demonstrate that oxidation at Te vacancy sites is comparable with that on defect-free regions, which predominantly govern the ambient degradation of semimetallic WTe2, in contrast to previous reports for semiconducting TMDs. The higher oxidation rate is therefore attributed to surface structural disorder induced by defect formation, which likely promotes adsorption of atmospheric species without altering the intrinsic oxidation energetics. Collectively, these results show that chalcogen vacancies in Td-WTe2 do not play a dominant role in controlling oxidation energetics through direct gas-defect interactions, thereby refining the understanding of its environmental stability which is crucial for synthesis and device fabrication strategies under ambient conditions.
A comprehensive understanding of exciton generation and transport in van der Waals layered transition metal dichalcogenides is essential for advancing high-performance optoelectronic devices. However, the nanometer-scale range and short lifetimes of excitons impede reliable characterization. Here, we overcome these limitations using a direct nanoscale photocurrent imaging technique that integrates a conductive atomic force microscope with continuous-wave excitation. By mapping local photocurrents in MoTe2/graphene heterostructures, we visualize exciton distribution and generation at the nanoscale. We observe a diffraction-like photocurrent pattern, indicating lateral redistribution of active excitonic carriers from the excitation center. Notably, the active excitonic-carrier region is strongly confined near the top few layers due to an electronic potential barrier. The highly confined excitons contribute to a high quantum yield (∼95%) by carrier multiplication in bulk MoTe2. Consequently, the enhanced exciton generation in a few layers can occur by unusually large exciton binding energy, lowered dielectric screening, strengthened carrier extraction from decreased barrier height, and the longer photocarrier lifetime of bulk MoTe2.
Colorectal cancer (CRC) patients with microsatellite-stable tumors typically resist immune checkpoint blockade (ICB) due to an immunosuppressive "cold" microenvironment. Photodynamic therapy (PDT) generates reactive oxygen species (ROS) to ablate tumor cells and induce immunogenic cell death (ICD), potentiating antitumor immunity. We previously demonstrated that neutrophil-derived nanovesicles (NNVs) retain tumor-suppressive cytotoxic payloads, including granzymes and perforin. Here, we engineered RGD-functionalized neutrophil nanovesicles encapsulating Ce6-loaded liposomes (RNC) via co-extrusion for targeted CRC photoimmunotherapy. RGD functionalization drives specific binding to integrin αvβ3-overexpressing CRC cells and selective in vivo tumor accumulation. Upon 660 nm irradiation, robust RNC-generated ROS synergizes with NNV cytotoxic proteins to trigger potent apoptosis and pronounced ICD. The resulting damage-associated molecular patterns (DAMPs) stimulate dendritic cell maturation and prime tumor-specific CD4+ and CD8+ T cell responses, effectively remodeling the microenvironment. In tumor-bearing mice, systemic RNC administration combined with local irradiation suppressed primary subcutaneous tumor growth and elicited significant abscopal effects on distant, non-irradiated tumors. Notably, co-administration with PD-1 blockade further amplified antitumor efficacy and systemic immune activation. This biomimetic nanoplatform integrates active targeting, photodynamic cytotoxicity, and ICD-driven immune priming, offering a synergistic strategy to convert "cold" CRC tumors into "hot" lesions and enhance checkpoint inhibitor therapy.
Nanoscale films play a central role in biology and osmotic separations. Their water/salt selectivity is often regarded as intrinsic property, favoring thinner membranes for faster permeation. Here we highlight and...
Near-Infrared (NIR) upconverting (UC) crystals of NaYF4 co-doped with Yb3+ as sensitizer and Er3+ as activator is one of the most widely applied upconversion material till date. The UC crystals...
Te vacancies accelerate surface oxidation of WTe 2 without measurably altering its apparent activation energy.
As wildfires intensify due to climate change and expanding development in fire-prone areas of the world, there is a critical need for scalable, bioinspired flame-retardant technologies that can be applied...
Single-photon emission (SPE) is an indispensable component of emerging quantum technologies, including quantum communication, computation, and sensing. While cryogenic platforms have demonstrated near-ideal SPE, their reliance on low-temperature operation limits scalability and practical deployment. This review focuses on recent progress toward efficient and stable room-temperature single-photon sources (RT-SPSs), with particular emphasis on semiconductor colloidal quantum dots (QDs) and metal-halide perovskite quantum dot (PQD) emitters based on key performance metrics such as photon purity, brightness, emission linewidth, and photostability. Special attention is given to emerging strategies that overcome room-temperature limitations, including surface and ligand engineering, defect control, and integration with advanced nanophotonic architectures. In particular, the role of chirality in QDs is highlighted as a powerful symmetry-breaking mechanism that enables polarization-selective emission, excitonic state control, and spin-dependent processes. Furthermore, coupling quantum emitters to plasmonic cavities, bound states in the continuum, and metasurfaces is discussed as an effective route to enhance light-matter interactions and access coherent regimes at ambient conditions. By consolidating recent experimental and theoretical advances, this review outlines key challenges, emerging solutions, and future directions toward scalable, RT-SPSs compatible with integrated quantum photonic platforms.
The magnetic responses of gold nanoparticles (AuNPs) continue to attract considerable interest because they contrast with the diamagnetic nature of bulk gold and remain challenging to investigate experimentally. The detection...
Supercapattery and overall water splitting are emerging technologies for storing energy and producing a carbon-free fuel source. The highly multifunctional electrodes are the most prominent factor for the supercapattery and...
The strong coupling in ion distribution and hence, the short range Coulombic interactions manifest in a multivalent electrolyte. The surface charge density arising through the protonation/deprotonation reactions is also influenced...
Lung cancer remains the leading cause of cancer death worldwide. Systemic drug delivery often results in low lung accumulation and high toxicity. Inhalable biomaterials offer a promising alternative by delivering...
Active packaging films endowed with multifunctional properties have emerged as effective systems for slowing ripening and maintaining the freshness of climacteric fruits. The present work demonstrates the fabrication of TiO₂/CDs-loaded...
The first step in designing a good catalyst for producing ammonia is to understand what activates the N 2 molecule, yet its origin is often unclear due to interactions between catalyst...
The nanoscale imaging of two-dimensional (2D) materials is critical for understanding their fundamental properties and potential uses in novel technological applications. Tip-enhanced spectroscopic (TES) studies on 2D materials have thus far been very fruitful, discovering heterogeneities once invisible to conventional imaging, and demonstrating light-matter interactions with the potential for new avenues in opto-electronic material control. Recent advances in this domain have pushed the boundaries of TES and its capabilities. Optimized fabrication methods, improved measurement systems, and innovative nano-optical techniques are all being actively demonstrated, providing excitement for future science approaching the horizon. This review serves to highlight new developments for advanced techniques in TES, discussing the state of TES on 2D materials and how it has shaped a need for such developments. Challenges in this domain that continue to linger will be discussed, as well as opportunities that remain waiting to be explored.
Aiming at the industrial pain points that thin-walled hard-brittle quartz crucibles are prone to surface defects including chipping pits and microcracks during machining, which results in a high scrap rate...
We present a systematic study of non-magnetic quantum corrals for tailoring electronic, magnetic, and superconducting properties on a triangular-lattice chiral superconductors in this paper. Our calculations reveal that quantum corrals...
The atomic/molecular layer deposition (ALD/MLD) technique is believed to provide unparallelled benefits for the fabrication of thin-film components for flexible 3D lithium-ion microbatteries, for which the nanoscale conformality of the...
Biomarker detection is critical for disease diagnostics, drug development, biomolecular assay design, and personalized medicine. Developing sensitive, multiplexed platforms for point-of-care settings remains a significant challenge. Ensemble techniques such as...
Surface-enhanced Raman spectroscopy (SERS) technology enables efficient detection of molecules, which have become an efficient tool for decoding life information. Constructing an appropriate nano-material structure is the key to improving...
