Nanomaterials (Basel)
February 2024
Ferromagnetic materials have been attracting great interest in the last two decades due to their application in spintronics devices. One of the hot research areas in magnetism is currently the two-dimensional materials, transition metal dichalcogenides (TMDCs), which have unique physical properties. The origins and mechanisms of transition metal dichalcogenides (TMDCs), especially the correlation between magnetism and defects, have been studied recently.
View Article and Find Full Text PDFMemristors, resistive switching memory devices, play a crucial role in the energy-efficient implementation of artificial intelligence. This study investigates resistive switching behavior in a lateral 2D composite structure composed of bilayer graphene and 2D diamond (diamane) nanostructures formed using electron beam irradiation. The resulting bigraphene/diamane structure exhibits nonlinear charge carrier transport behavior and a significant increase in resistance.
View Article and Find Full Text PDFACS Appl Mater Interfaces
May 2023
High-quality BiSe thin films with topological insulating properties at room temperature have recently attracted much attention as one of the promising materials for realizing innovative electronic and optoelectronic devices. Here, we report the high crystallinity growth of BiSe thin films on a patterned sapphire substrate (PSS) by using a vapor-phase transport deposition with minimizing thermal dissociation of Se atoms vaporized in BiSe powder. This PSS not only reduces the large dislocation of heterogeneously grown BiSe on a sapphire substrate but also induces enhanced light absorption in the visible to near-infrared (IR) ranges compared to BiSe on planar sapphire substrates.
View Article and Find Full Text PDFIn the presented paper, we studied bilayer CVD graphene transferred to a langasite substrate and irradiated with a focused electron beam through a layer of polymethyl methacrylate (PMMA). Changes in the Raman spectra and an increase in the electrical resistance of bigraphene after irradiation indicate a local phase transition associated with graphene diamondization. The results are explained in the framework of the theory of a chemically induced phase transition of bilayer graphene to diamane, which can be associated with the release of hydrogen and oxygen atoms from PMMA and langasite due to the "knock-on" effect, respectively, upon irradiation of the structure with an electron beam.
View Article and Find Full Text PDFNitrogen dioxide (NO) gas has emerged as a severe air pollutant that causes damages to the environment, human life and global ecosystems etc. However, the currently available NO gas sensors suffers from insufficient selectivity, sensitivity and long response times that impeding their practical applicability for room temperature (RT) gas sensing. Herein, we report a high performance langasite (LGS) based surface acoustic wave (SAW) RT NO gas sensor using 2-dimensional (2D) g-CN@TiO nanoplates (NP) with {001} facets hybrid nanocomposite as a chemical interface.
View Article and Find Full Text PDFNanomaterials (Basel)
February 2021
High crystalline ZnO nanorods (NRs) on Zn pre-deposited graphene/Cu sheet without graphene transfer process have been fabricated by self-catalyzed vapor-phase transport synthesis. Here, the pre-deposited Zn metal on graphene not only serves as a seed to grow the ZnO NRs, but also passivates the graphene underneath. The temperature-dependent photoluminescence spectra of the fabricated ZnO NRs reveal a dominant peak of 3.
View Article and Find Full Text PDFTin sulfides are promising materials in the fields of photoelectronics and photovoltaics because of their appropriate energy bands. However, doping in SnS can improve the stability and robustness of this material in potential applications. Herein, we report the synthesis of SnS nanoflakes with Zn doping via simple hydrothermal route.
View Article and Find Full Text PDFAtmospheric doping of supported graphene was investigated by Raman scattering under different pressures. Various Raman spectra parameters were found to depend on the pressure and the substrate material. The results are interpreted in terms of atmospheric adsorption leading to a change in graphene charge carrier density and the effect of the substrate on the electronic and phonon properties of graphene.
View Article and Find Full Text PDFTin monosulfide (SnS) nanostructures have attracted huge attention recently because of their high absorption coefficient, high photoconversion efficiencies, low energy cost, ease of deposition, and so on. Here, in this paper, we report on the low-cost hydrothermal synthesis of the self-assembled SnS nanoflake-like structures in terms of performance for the photodetectors. High-performance photodetectors were fabricated using SnS nanoflakes as active layers and graphene as the lateral electrodes.
View Article and Find Full Text PDFMicro-fabricated single-layer graphenes (SLGs) on a silicon dioxide (SiO)/Si substrate, a silicon nitride (SiN) membrane, and a suspended architecture are presented for their use as temperature sensors. These graphene temperature sensors act as resistance temperature detectors, showing a quadratic dependence of resistance on the temperature in a range between 283 K and 303 K. The observed resistance change of the graphene temperature sensors are explained by the temperature dependent electron mobility relationship (~T) and electron-phonon scattering.
View Article and Find Full Text PDFPhotocatalytic oxidation of graphene with ZnO nanoparticles was found to create self-assembled graphene oxide/graphene (G/GO) photosensitive heterostructures, which can be used as memristors. Oxygen groups released during photodecomposition of water molecules on the nanoparticles under ultraviolet light, oxidized graphene, locally forming the G/GO heterojunctions with ultra-high density. The G/GO nanostructures have non-linear current-voltage characteristics and switch the resistance in the dark and under white light, providing four resistive states at room temperature.
View Article and Find Full Text PDF4H-SnS layered crystals synthesized by a hydrothermal method were used to obtain via liquid phase exfoliation quantum dots (QDs), consisting of a single layer (SLQDs) or multiple layers (MLQDs). Systematic downshift of the peaks in the Raman spectra of crystals with a decrease in size was observed. The bandgap of layered QDs, estimated by UV-visible absorption spectroscopy and the tunneling current measurements using graphene probes, increases from 2.
View Article and Find Full Text PDFEtching of materials on the nanoscale is a challenging but necessary process in nanomaterials science. Gas sensing using a single ZnO nanocactus (NC), which was prepared by facile isotropic nanoetching of zinc oxide nanorods (NR) grown by chemical vapor deposition (CVD) using an organic photoresist (PR) by a thermochemical reaction, is reported in this work. PR consists of carboxylic acid groups (COOH) and cyclopentanone (C5H8O), which can react with zinc and oxygen atoms, respectively, on the surface of a ZnO NR.
View Article and Find Full Text PDFA photovoltaic device was successfully grown solely based on the single ZnO p-n homojunction nanowire. The ZnO nanowire p-n diode consists of an as-grown n-type segment and an in situ arsenic-doped p-type segment. This p-n homojunction acts as a good photovoltaic cell, producing a photocurrent almost 45 times larger than the dark current under reverse-biased conditions.
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