A novel atomic layer deposition (ALD) process for nickel oxide (NiO) is developed using a recently reported diazadienyl complex, Ni(DAD), and ozone. A window of constant growth per cycle is found between 185 and 200 °C at 0.12 nm/cycle, among the highest reported for ALD NiO. For films deposited at 200 °C, grazing-incidence X-ray diffraction indicates a randomly oriented polycrystalline cubic NiO phase. X-ray photoelectron spectroscopy shows good agreement with bulk NiO reference spectra and no detectable impurities. Atomic force microscopy reveals low root mean square roughness of 0.6 nm for an 18 nm thick film. The refractive index of 2.36 and an electronic bandgap of 3.78 eV, as determined by variable angle spectroscopic ellipsometry, are close to reported values for bulk and thin film NiO. Finally, fabricated Ag/NiO/n-Si/In heterojunction diodes show a current-voltage asymmetry of 1.27 × 10 at 2.3 V and an ideality factor of 3.5, confirming the intrinsic p-type semiconducting behavior of transparent NiO.
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http://dx.doi.org/10.1021/acsami.9b08926 | DOI Listing |
Sci Rep
December 2024
Department of Physics, Shahid Beheshti University, Tehran, 1983969411, Iran.
Machine learning interatomic potentials, as a modern generation of classical force fields, take atomic environments as input and predict the corresponding atomic energies and forces. We challenge the commonly accepted assumption that the contribution of an atom can be learned from the short-range local environment of that atom. We employ density functional theory calculations to quantify the decay of the induced electron density and electrostatic potential in response to local perturbations throughout insulating, semiconducting and metallic samples of different dimensionalities.
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December 2024
Centre of Advanced Research in Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry, 41A, Grigore Ghica Voda Alley, 700487, Iasi, Romania.
One of the biggest issues of wide bandgap semiconductor use in photocatalytic wastewater treatment is the reusability of the material and avoiding the contamination of water with the material itself. In this paper, we report on a novel TiO aeromaterial (aero-TiO) consisting of hollow microtetrapods with ZnTiO inclusions. Atomic layer deposition has been used to obtain particles of unique shape allowing them to interlock thereby protecting the photocatalyst from erosion and damage when incorporated in active filters.
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December 2024
TCS Research, Sahyadri Park 2, Rajiv Gandhi Infotech Park, Hinjewadi Phase 3, Pune 411057, India.
Realization of a sustainable hydrogen economy in the future requires the development of efficient and cost-effective catalysts for its production at scale. MXenes (MX) are a class of 2D materials with 'n' layers of carbon or nitrogen (X) interleaved by 'n+1' layers of transition metal (M) and have emerged as promising materials for various applications including catalysts for hydrogen evolution reaction (HER). Their properties are intimately related to both their composition and their atomic structure.
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December 2024
Central European Institute of Technology, Brno University of Technology, Purkynova 123, 612 00 Brno, Czech Republic.
The current study investigates and compares the biological effects of ultrathin conformal coatings of zirconium dioxide (ZrO) and vanadium pentoxide (VO) on osteoblastic MG-63 cells grown on TiO nanotube layers (TNTs). Coatings were achieved by the atomic layer deposition (ALD) technique. TNTs with average tube diameters of 15, 30, and 100 nm were fabricated on Ti substrates (via electrochemical anodization) and were used as primary substrates for the study.
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December 2024
Department of Electrical and Computer Engineering, University of Florida, Gainesville, FL, 32611, USA.
Nanoelectromechanical systems (NEMS) incorporating atomic or molecular layer van der Waals materials can support multimode resonances and exotic nonlinear dynamics. Here we investigate nonlinear coupling of closely spaced modes in a bilayer (2L) molybdenum disulfide (MoS) nanoelectromechanical resonator. We model the response from a drumhead resonator using equations of two resonant modes with a dispersive coupling term to describe the vibration induced frequency shifts that result from the induced change in tension.
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