An Aerosol-Assisted Chemical Vapor Deposition Route to Tin-Doped Gallium Oxide Thin Films with Optoelectronic Properties

Gallium oxide is a wide-bandgap compound semiconductor material renowned for its diverse applications spanning gas sensors, liquid crystal displays, transparent electrodes, and ultraviolet detectors. This paper details the aerosol assisted chemical vapor deposition synthesis of tin doped gallium oxide thin films using gallium acetylacetonate and monobutyltin trichloride dissolved in methanol. It was observed that Sn doping resulted in a reduction in the transmittance of Ga2O3 films within the visible spectrum, while preserving the wide bandgap characteristics of 4.8 eV. Furthermore, Hall effect testing revealed a substantial decrease in the resistivity of Sn-doped Ga2O3 films, reducing it from 4.2 × 106 Ω cm to 2 × 105 Ω cm for the 2.5 at. % Sn:Ga2O3 compared to the nominally undoped Ga2O3

An Acute Evolving Flaccid Quadriparesis in an Elderly Woman

Andrew Larner and colleagues discuss the differential diagnosis, investigation, and management of a 72-year-old woman presenting with progressive lower limb weakness who develops an acute evolving flaccid quadriparesis

n-Type conducting P doped ZnO thin films via chemical vapor deposition

Extrinsically doped ZnO thin films are of interest due to their high electrical conductivity and transparency to visible light. In this study, P doped ZnO thin films were grown on glass substrates via aerosol assisted chemical vapour deposition. The results show that P is a successful dopant for ZnO in the V+ oxidation state and is able to reduce resistivity to 6.0 × 10−3 Ω cm while maintaining visible light transmittance at ∼75%. The thins films were characterized by X-ray diffraction studies that showed only Bragg peaks for the wurtzite ZnO phase. Fitting of the diffraction data to a Le Bail model also showed a general expansion of the ZnO unit cell upon doping due to the substitution of Zn2+ ions with the larger P5+

Transparent and Conductive Molybdenum-Doped ZnO Thin Films via Chemical Vapor Deposition

Extrinsically doped ZnO is widely used as a transparent conducting electrode and has the potential to alleviate the demand on the expensive but ubiquitous Sn-doped In2O3. Here, we report for the first time the synthesis and characterization of molybdenum-doped ZnO via a chemical vapor deposition route. Films were grown by using diethylzinc, molybdenum hexacarbonyl, toluene, and methanol. All films had visible light transmittance of ∼80% and electrical resistivity of 10–3 Ω·cm with the lowest resistivity of 2.6 × 10–3 Ω·cm observed for the 0.57 at. % Mo-doped film. X-ray photoelectron spectroscopy of the surface species and X-ray diffraction based calculations of the ZnO unit cell parameters suggest that Mo is present in the 4+ oxidation state, thus contributing two electrons for electrical conduction for every Zn2+ ion replaced in the lattice

Transparent and conducting boron doped ZnO thin films grown by aerosol assisted chemical vapor deposition

Boron doped zinc oxide thin films via aerosol assisted chemical vapor deposition with resisitivities as low as 5.1 × 10−3 Ω cm

Visible-Light-Active Iodide-Doped BiOBr Coatings for Sustainable Infrastructure

The search for efficient materials for sustainable infrastructure is an urgent challenge toward potential negative emission technologies and the global environmental crisis. Pleasant, efficient sunlight-activated coatings for applications in self-cleaning windows are sought in the glass industry, particularly those produced from scalable technologies. The current work presents visible-light-active iodide-doped BiOBr thin films fabricated using aerosol-assisted chemical vapor deposition. The impact of dopant concentration on the structural, morphological, and optical properties was studied systematically. The photocatalytic properties of the parent materials and as-deposited doped films were evaluated using the smart ink test. An optimized material was identified as containing 2.7 atom % iodide dopant. Insight into the photocatalytic behavior of these coatings was gathered from photoluminescence and photoelectrochemical studies. The optimum photocatalytic performance could be explained from a balance between photon absorption, charge generation, carrier separation, and charge transport properties under 450 nm irradiation. This optimized iodide-doped BiOBr coating is an excellent candidate for the photodegradation of volatile organic pollutants, with potential applications in self-cleaning windows and other surfaces

Combined Effect of Temperature Induced Strain and Oxygen Vacancy on Metal‐Insulator Transition of VO2 Colloidal Particles

Vanadium dioxide (VO2) is a promising material in the development of thermal and electrically sensitive devices due to its first order reversible metal-insulator transition (MIT) at 68 °C. Such high MIT temperature (TC) largely restricts its widespread application which could be enabled if a straightforward tuning mechanism were present. Here this need is addressed through a facile approach that uses the combined effects of temperature induced strain and oxygen vacancies in bulk VO2 colloidal particles. A simple thermal annealing process under varying vacuum is used to achieve phase transformation of metastable VO2(A) into VO2(M2), (M2+M3), (M1) and higher valence V6O13 phases. During this process, distinct multiple phase transitions including increased as well as suppressed TC are observed with respect to the annealing temperature and varied amount of oxygen vacancies respectively. The latent heat of phase transition is also significantly improved upon thermal annealing by increasing the crystallinity of the samples. This work not only offers a facile route for selective phase transformation of VO2 as well as to manipulate the phase transition temperature, but also contributes significantly to the understanding of the role played by oxygen vacancies and temperature induced stress on MIT which is essential for VO2 based applications

New Device for Intrinsic Hand Muscle Strength Measurement: An Alternative to Strain Gauge Handheld Dynamometer

© The Author(s) 2017. An accurate measurement of intrinsic hand muscle strength (IHMS) is required by clinicians for effective clinical decision-making, diagnosis of certain diseases, and evaluation of the outcome of treatment. In practice, the clinicians use Intrins-o-meter and Rotterdam Intrinsic Hand Myometer for IHMS measurement. These are quite bulky, expensive, and possess poor interobserver reliability (37–52%) and sensitivity. The purpose of this study was to develop an alternative lightweight, accurate, cost-effective force measurement device with a simple electronic circuit and test its suitability for IHMS measurement. The device was constructed with ketjenblack/deproteinized natural rubber sensor, 1-MΩ potential divider, and Arduino Uno through the custom-written software. Then, the device was calibrated and tested for accuracy and repeatability within the force range of finger muscles (100 N). The 95% limit of agreement in accuracy from −1.95 N to 2.06 N for 10 to 100 N applied load and repeatability coefficient of ±1.91 N or 6.2% was achieved. Furthermore, the expenditure for the device construction was around US$ 53. For a practical demonstration, the device was tested among 16 participants for isometric strength measurement of the ulnar abductor and dorsal interossei. The results revealed that the performance of the device was suitable for IHMS measurement

Visible-Light-Active Iodide-Doped BiOBr Coatings for Sustainable Infrastructure

The search for efficient materials for sustainable infrastructure is an urgent challenge toward potential negative emission technologies and the global environmental crisis. Pleasant, efficient sunlight-activated coatings for applications in self-cleaning windows are sought in the glass industry, particularly those produced from scalable technologies. The current work presents visible-light-active iodide-doped BiOBr thin films fabricated using aerosol-assisted chemical vapor deposition. The impact of dopant concentration on the structural, morphological, and optical properties was studied systematically. The photocatalytic properties of the parent materials and as-deposited doped films were evaluated using the smart ink test. An optimized material was identified as containing 2.7 atom % iodide dopant. Insight into the photocatalytic behavior of these coatings was gathered from photoluminescence and photoelectrochemical studies. The optimum photocatalytic performance could be explained from a balance between photon absorption, charge generation, carrier separation, and charge transport properties under 450 nm irradiation. This optimized iodide-doped BiOBr coating is an excellent candidate for the photodegradation of volatile organic pollutants, with potential applications in self-cleaning windows and other surfaces

High Defect Nanoscale ZnO Films with Polar Facets for Enhanced Photocatalytic Performance

The fabrication of highly efficient photocatalytic thin films has important consequences for self-cleaning, organic pollutant decomposition, and antimicrobial coatings for a variety of applications. Here, we developed a simple synthesis method to produce efficient, high-surface-area zinc oxide (ZnO) photocatalytic films using aerosol-assisted chemical vapor deposition. This approach used mixtures of methanol and acetic acid to promote preferential growth and exposure of polar facets, which favor photocatalytic activity. Interestingly, the initial enhanced efficiency of the films was correlated to structural defects, likely oxygen vacancies, as supported by photoluminescence spectroscopy results. Discussion over the influence of such defects on photocatalytic performance is described, and the need for strategies to develop high-surface-area materials containing stable defects is highlighted