Tuning Exciton Emission via Ferroelectric Polarization at a Heterogeneous Interface between a Monolayer Transition Metal Dichalcogenide and a Perovskite Oxide Membrane.

We demonstrate the integration of a thin BaTiO (BTO) membrane with monolayer MoSe in a dual-gate device that enables in situ manipulation of the BTO ferroelectric polarization with a voltage pulse. While two-dimensional (2D) transition metal dichalcogenides (TMDs) offer remarkable adaptability, their hybrid integration with other families of functional materials beyond the realm of 2D materials has been challenging. Released functional oxide membranes offer a solution for 2D/3D integration via stacking.

Unusually large exciton binding energy in multilayered 2H-MoTe.

Although large exciton binding energies of typically 0.6-1.0 eV are observed for monolayer transition metal dichalcogenides (TMDs) owing to strong Coulomb interaction, multilayered TMDs yield relatively low exciton binding energies owing to increased dielectric screening.

Colloidal Synthesis of MoSe/WSe Heterostructure Nanoflowers via Two-Step Growth.

The ability to control the active edge sites of transition metal dichalcogenides (TMDs) is crucial for modulating their chemical activity for various electrochemical applications, including hydrogen evolution reactions. In this study, we demonstrate a colloidal synthetic method to prepare core-shell-like heterostructures composed of MoSe and WSe via a two-step sequential growth. By overgrowing WSe on the surface of preexisting MoSe nanosheet edges, MoSe-core/WSe-shell heterostructures were successfully obtained.

Transition-Metal Dichalcogenide Artificial Antibodies with Multivalent Polymeric Recognition Phases for Rapid Detection and Inactivation of Pathogens.

Antibodies are recognition molecules that can bind to diverse targets ranging from pathogens to small analytes with high binding affinity and specificity, making them widely employed for sensing and therapy. However, antibodies have limitations of low stability, long production time, short shelf life, and high cost. Here, we report a facile approach for the design of luminescent artificial antibodies with nonbiological polymeric recognition phases for the sensitive detection, rapid identification, and effective inactivation of pathogenic bacteria.

Macroscopic on-site evaluation after EUS-guided fine needle biopsy may replace rapid on-site evaluation.

Background And Objectives: Rapid on-site cytologic evaluation (ROSE) increases the diagnostic yield of EUS-FNA. However, ROSE requires the presence of a cytopathologist and additional cost and time for slide staining and interpretation. Macroscopic on-site examination (MOSE) was recently introduced as an alternative to ROSE and showed high accuracy for the use in pathologic diagnosis.

Inherent Resistance of Seed-Mediated Grown MoSe Monolayers to Defect Formation.

Recent progress in the chemical vapor deposition technique toward growing large-area and single-crystalline two-dimensional (2D) transition metal dichalcogenides (TMDs) has resulted in an electronic/optoelectronic device performance that rivals that of their top-down counterparts, despite the extensive use of hydrogen, a common reducing agent that readily generates defects in TMDs. Herein, we report that 2D MoSe domains containing oxide seeds are resistant to hydrogen-induced defect generation. Specifically, we observed that the etching of the edges of seed-containing MoSe was significantly less than that of pristine MoSe, without apparent seed particles, under the same H annealing conditions.

Universal Oriented van der Waals Epitaxy of 1D Cyanide Chains on Hexagonal 2D Crystals.

The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and CuAuCN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h-BN, WS, MoS, WSe, MoSe, and MoTe).

Optoelectronics of Multijunction Heterostructures of Transition Metal Dichalcogenides.

Among p-n junction devices with multilayered heterostructures with WSe and MoSe, a device with the MoSe-WSe-MoSe (NPN) structure showed a remarkably high photoresponse, which was 1000 times higher than the MoSe-WSe (NP) structure. The ideality factor of the NPN structure was estimated to be ∼1, lower than that of the NP structure. It is claimed that the NPN structure formed a thinner depletion region than that of the NP structure because of the difference of carrier concentrations of MoSe and WSe.

Hierarchical Tubular-Structured MoSe Nanosheets/N-Doped Carbon Nanocomposite with Enhanced Sodium Storage Properties.

Intimately coupled carbon/molybdenum-based hierarchical nanostructures are promising anodes for high-performance sodium-ion batteries owing to the combined effects of the two components and their robust structural stability. Mo-polydopamine (PDA) complexes are appealing precursors for the preparation of various Mo-based nanostructures containing N-doped carbon (NC). A facile method for the fabrication of hierarchical tubular nanocomposites with intimately coupled MoSe and NC nanosheets has been developed, which involves the preparation of Mo-PDA hybrid nanotubes through a chemical route followed by two heat treatments.

Identifying substitutional oxygen as a prolific point defect in monolayer transition metal dichalcogenides.

Chalcogen vacancies are generally considered to be the most common point defects in transition metal dichalcogenide (TMD) semiconductors because of their low formation energy in vacuum and their frequent observation in transmission electron microscopy studies. Consequently, unexpected optical, transport, and catalytic properties in 2D-TMDs have been attributed to in-gap states associated with chalcogen vacancies, even in the absence of direct experimental evidence. Here, we combine low-temperature non-contact atomic force microscopy, scanning tunneling microscopy and spectroscopy, and state-of-the-art ab initio density functional theory and GW calculations to determine both the atomic structure and electronic properties of an abundant chalcogen-site point defect common to MoSe and WS monolayers grown by molecular beam epitaxy and chemical vapor deposition, respectively.

Hydrogen-assisted step-edge nucleation of MoSe monolayers on sapphire substrates.

The fabrication of large-area single crystalline monolayer transition metal dichalcogenides (TMDs) is essential for a range of electric and optoelectronic applications. Chemical vapor deposition (CVD) is a promising method to achieve this goal by employing orientation control or alignment along the crystalline lattice of the substrate such as sapphire. On the other hand, a fundamental understanding of the aligned-growth mechanism of TMDs is limited.

Flexible Vertical p-n Diode Photodetectors with Thin N-type MoSe Films Solution-Processed on Water Surfaces.

Two-dimensional (2D) nanosheets of transition metal dichalcogenides (TMDs) are of significant interest for potential photoelectronic applications. However, the fabrication of solution-processed arrays of mechanically flexible thin TMD films-based vertical type p-n junction photodetectors over a large area is a great challenge. Our method is based on controlled solvent evaporation of MoSe suspension spread on water surface.

2D transition metal dichalcogenides with glucan multivalency for antibody-free pathogen recognition.

The ability to control the dimensions and properties of nanomaterials is fundamental to the creation of new functions and improvement of their performances in the applications of interest. Herein, we report a strategy based on glucan multivalent interactions for the simultaneous exfoliation and functionalization of two-dimensional transition metal dichalcogenides (TMDs) in an aqueous solution. The multivalent hydrogen bonding of dextran with bulk TMDs (WS, WSe, and MoSe) in liquid exfoliation effectively produces TMD monolayers with binding multivalency for pathogenic bacteria.

The Integrated Genomic Landscape of Thymic Epithelial Tumors.

Thymic epithelial tumors (TETs) are one of the rarest adult malignancies. Among TETs, thymoma is the most predominant, characterized by a unique association with autoimmune diseases, followed by thymic carcinoma, which is less common but more clinically aggressive. Using multi-platform omics analyses on 117 TETs, we define four subtypes of these tumors defined by genomic hallmarks and an association with survival and World Health Organization histological subtype.