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Abstract Tomonaga-Luttinger liquid (TLL) behavior in one-dimensional systems has been predicted and shown to occur at semiconductor-to-metal transitions within two-dimensional materials. Reports of one-dimensional defects hosting a Fermi liquid or a TLL have suggested a dependence on the underlying substrate, however, unveiling the physical details of electronic contributions from the substrate require cross-correlative investigation. Here, we study TLL formation within defectively engineered WS₂atop graphene, where band structure and the atomic environment is visualized with nano angle-resolved photoelectron spectroscopy, scanning tunneling microscopy and spectroscopy, and non-contact atomic force microscopy. Correlations between the local density of states and electronic band dispersion elucidated the electron transfer from graphene into a TLL hosted by one-dimensional metal (1DM) defects. It appears that the vertical heterostructure with graphene and the induced charge transfer from graphene into the 1DM is critical for the formation of a TLL. 

Thin conducting films are distinct from bulk materials and have become prevalent over the past decades as they possess unique physical, electrical, optical, and mechanical characteristics. Comprehending these essential properties for developing novel materials with tailored features for various applications is very important. Research on these conductive thin films provides us insights into the fundamental principles, behavior at different dimensions, interface phenomena, etc. This study comprehensively analyzes the intricacies of numerous commonly used thin conducting films, covering from the fundamentals to their advanced preparation methods. Moreover, the article discusses the impact of different parameters on those thin conducting films’ electronic and optical properties. Finally, the recent future trends along with challenges are also highlighted to address the direction the field is heading towards. It is imperative to review the study to gain insight into the future development and advancing materials science, thus extending innovation and addressing vital challenges in diverse technological domains. 

W e present a scalable solution-processing method for fabricating high-quality graphene and graphene/1T-MoS 2 heterostructure films. The process begins with the synthesis of potassium-intercalated graphite (KC 8 ), which is exfoliated in tetrahydrofuran (THF) to produce stable dispersions of negatively charged (electron rich) graphene sheets. The graphene is subsequently transferred to water, forming a surfactant-free aqueous dispersion suitable for creating homogenous graphene films via vacuum filtration and stamping. Additionally, graphene is combined with 1T-MoS 2 nanosheets to fabricate graphene/1T-MoS 2 bulk heterostructure films. Comprehensive characterization, including X-ray diffraction (XRD), absorption spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy ( TEM), Raman spectroscopy, and X-ray photon emission spectroscopy (XPS), reveals that the heterostructure films exhibit enhanced optical and electronic properties, including improved light absorption, which could lead to novel photo-responsive devices. Raman spectroscopy shows significant changes in the graphene’s structural a nd electronic properties upon interaction with MoS 2 , indicating strong interlayer coupling and potential charge transfer between the layered components. The g raphene films demonstrate highly sensitive detection of dopamine (DA), while the graphene/1T-MoS 2 b ulk heterostructure films exhibit capacitance values up to 3 8.3 Fg − 1 at 5 mV/s in non-aqueous electrolytes. These results highlight the potential of these films for advanced applications in molecular sensing and energy storage. 

Early virus identification is a key component of both patient treatment and epidemiological monitoring. In the case of influenza A virus infections, where the detection of subtypes associated with bird flu in humans could lead to a pandemic, rapid subtype-level identification is important. Surface-enhanced Raman spectroscopy coupled with machine learning can be used to rapidly detect and identify viruses in a label-free manner. As there is a range of available excitation wavelengths for performing Raman spectroscopy, we must choose the best one to permit discrimination between highly similar subtypes of a virus. We show that the spectra produced by influenza A subtypes H1N1 and H3N2 exhibit a higher degree of dissimilarity when using 785 nm excitation wavelength in comparison with 532 nm excitation wavelength. Furthermore, the cross-validated area under the curve (AUC) for identification was higher for the 785 nm excitation, reaching 0.95 as compared to 0.86 for 532 nm. Ultimately, this study suggests that exciting with a 785 nm wavelength is better able to differentiate two closely related influenza viruses and likely can extend to other closely related pathogens. 

Abstract 2D dilute magnetic semiconductors have been recently reported in transition metal dichalcogenides doped with spin‐polarized transition metal atoms, for example vanadium‐doped WS₂monolayers, which exhibit room‐temperature ferromagnetic ordering. However, a broadband characterization of the electronic band structure of these doped WS₂monolayers and its dependence on vanadium concentration is still lacking. Therefore, power‐dependent photoluminescence, resonant four‐wave mixing, and differential reflectance spectroscopies are performed here to study optical transitions close to the A exciton energy of vanadium‐doped WS₂monolayers at three different doping levels. Instead of a single A exciton peak, vanadium‐doped samples exhibit two photoluminescence peaks associated with transitions from a donor‐like level and the conduction band minima. Moreover, resonant Raman and second‐harmonic generation experiments reveal a blueshift in the B exciton energy but no energy change in the C exciton after vanadium doping. Density functional theory calculations show that the band structure is sensitive to the HubbardUcorrection for vanadium, and several scenarios are proposed to explain the two photoluminescence peaks around the A exciton energy region. This work provides the first broadband optical characterization of these 2D dilute magnetic semiconductors, shedding light on the novel and tunable electronic features of V‐doped WS₂ monolayers. 

Abstract Engineering electronic bandgaps is crucial for applications in information technology, sensing, and renewable energy. Transition metal dichalcogenides (TMDCs) offer a versatile platform for bandgap modulation through alloying, doping, and heterostructure formation. Here, the synthesis of a 2D Mo_xW_1‐xS₂graded alloy is reported, featuring a Mo‐rich center that transitions to W‐rich edges, achieving a tunable bandgap of 1.85 to 1.95 eV when moving from the center to the edge of the flake. Aberration‐corrected high‐angle annular dark‐field scanning transmission electron microscopy showed the presence of sulfur monovacancy, V_S, whose concentration varied across the graded Mo_xW_1‐xS₂layer as a function of Mo content with the highest value in the Mo‐rich center region. Optical spectroscopy measurements supported by ab initio calculations reveal a doublet electronic state of V_S, which is split due to the spin‐orbit interaction, with energy levels close to the conduction band or deep in the bandgap depending on whether the vacancy is surrounded by W atoms or Mo atoms. This unique electronic configuration of V_Sin the alloy gave rise to four spin‐allowed optical transitions between the V_Slevels and the valence bands. The study demonstrates the potential of defect and optical engineering in 2D monolayers for advanced device applications.