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Controlling the magnetic and optical responses of a MoS 2 monolayer by lanthanide substitutional doping: a first-principles study
Here, the electronic, magnetic and optical properties of lanthanide substitutional doping (~2% concentration) on the MoS 2 monolayer have been investigated within the density functional theory formalism together with the Hubbard correction (DFT+U). The dopants investigated include Ce, Eu, Gd, Lu and Tm. The calculated dopant substitutional energies under both Mo-rich and S-rich conditions suggest that it is possible to experimentally realize the lanthanide doped MoS 2 monolayer systems. The Eu, Gd and Tm dopants induce strong magnetization in the host lattice. The electronic structure calculations reveal that the dopants have a p-type character and they exhibit a half-metallic behavior in the Gd and Eu doped systems. A dilute magnetic semiconducting behavior can also be realized in Gd, Eu and Tm doped systems by slightly tuning the Fermi level. All the dopants refine the optical responses of the host system with the onset of the optical absorption edge shifting to lower energies within the visible range (red shift phenomenon). We observe an optical anisotropy for two different directions of the electric field (E) polarizations, i.e. parallel, E∥, and perpendicular, E⊥, to the xy-plane. Lanthanide substitutional doping significantly influences the electron energy loss spectra (EELS), absorption spectra, and dielectric properties of the host MoS 2 monolayer. Furthermore, we notice that lanthanide substitutional doping could enhance the photocatalytic properties of the MoS 2 monolayer.
Universal nanothin silk coatings via controlled spidroin self-assembly
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Robust and well-controlled TiO 2 –Al 2 O 3 binary nanoarray-integrated ceramic honeycomb for efficient propane combustion
Well-tuned TiO 2 –Al 2 O 3 binary nanoarrays had been fabricated onto ceramic honeycombs and exhibited excellent robustness and catalytic activity for propane oxidation.
Fermi resonance controlled product branching in the H + HOD reaction
Excitation of the first overtone of bending mode results in a significant enhancement in the HD + OH channel due to the 1 : 2 Fermi resonance between the fundamental OD stretch and the first overtone of the bend.
Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates
Perturbation of molecular packing and dielectric environment at a quantum dot surface can promote singlet fission in diphenylpentacene aggregates.
Sub-monolayer control of the growth of oxide films on mesoporous materials
Mixed oxide surfaces were developed via the atomic layer deposition of a variety of oxide thin films on mesoporous materials.
Depletion layer controls photocatalytic hydrogen evolution with p-type gallium phosphide particles
p-Type gallium phosphide (p-GaP) is an established photocathode material for hydrogen evolution, however, photocatalytic hydrogen evolution from p-GaP photocatalysts generally proceeds with very low activity. This can be understood on the basis of the space charge layer model presented here.
Perdeuteration of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (d-MEH-PPV): control of microscopic charge-carrier spin–spin coupling and of magnetic-field effects in optoelectronic devices
Replacing all protons on a polymer by deuterium has a dramatic impact on spin-dependent properties of the material in devices.
Remote controlled optical manipulation of bimetallic nanoparticle catalysts using peptides
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Rational design of guiding elements to control folding topology in i-motifs with multiple quadruplexes
Nucleic acids are versatile scaffolds that accommodate a wide range of precisely defined operational characteristics.
Controlling toughness of polymer-grafted nanoparticle composites for impact mitigation
Polymer toughness is typically dictated by the entanglement density. Here we demonstrate a new paradigm via polymer-grafted nanocomposites that couples segmental dynamics with the entanglement concept for enhanced toughness at high deformation rates.
Controlling the Co–S coordination environment in Co-doped WS 2 nanosheets for electrochemical oxygen reduction
The impact of Co–S coordination environment in pH 7 ORR catalysis is evaluated using dilute Co atoms adsorbed on WS 2 nanosheets. Optimal reactivity is achieved when Co is coordinated to both sulfur atoms on WS 2 and labile solvent ligands.
Thermal preconditioning of membrane stress to control the shapes of ultrathin crystals
A 2D phospholipid crystal (dark) grows within a fluid vesicle membrane (light), starting as a small flower shape. While the area of the crystal grows progressively, the flower shape is preserved, a result of tension pre-conditioning.
Modulation doping to control the high-density electron gas at a polar/non-polar oxide interface
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Shape controlled Sn doped ZnO nanostructures for tunable optical emission and transport properties
Pure and Sn doped ZnO nanostructures have been grown on SiO{sub 2}/Si substrates by vapor-solid technique without using any catalysts. It has been found that the morphology of the nanostructures depend strongly on the growth temperature and doping concentration. By proper tuning of the growth temperature, morphology of pure ZnO can be changed from tetrapods to multipods. On the other hand, by varying the doping concentration of Sn in ZnO, the morphology can be tuned from tetrapods to flower-like multipods to nanowires. X-ray diffraction pattern reveals that the nanostructures have a preferred (0002) growth orientation, and they are tensile strained with the increase of Sn doping in ZnO. Temperature-dependent photoluminescence characteristics of these nanostructures have been investigated in the range from 10 to 300 K. Pure ZnO tetrapods exhibited less defect state emissions than that of pure ZnO multipods. The defect emission is reduced with low concentration of Sn doping, but again increases at higher concentration of doping because of increased defects. Transport properties of pure and Sn doped ZnO tetrapods have been studied using complex-plane impedance spectroscopy. The contribution from the arms and junctions of a tetrapod could be distinguished. Sn doped ZnO samples showed lower conductivity but higher relaxation time than that of pure ZnO tetrapods.