Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Wei Jiang Yeh is active.

Publication


Featured researches published by Wei Jiang Yeh.


Journal of Applied Physics | 2006

Principles and mechanisms of gas sensing by GaN nanowires functionalized with gold nanoparticles

Vladimir Dobrokhotov; David N. McIlroy; M. Grant Norton; A. Abuzir; Wei Jiang Yeh; Ian H. Stevenson; R. Pouy; J. Bochenek; M. Cartwright; Lidong Wang; J. Dawson; Miles F. Beaux; Chris Berven

Electrical properties of a chemical sensor constructed from mats of GaN nanowires decorated with gold nanoparticles as a function of exposure to Ar, N2, and methane are presented. The Au nanoparticle decorated nanowires exhibited chemically selective electrical responses. The sensor exhibits a nominal response to Ar and slightly greater response for N2. Upon exposure to methane the conductivity is suppressed by 50% relative to vacuum. The effect is fully reversible and is independent of exposure history. We offer a model by which the change in the current is caused by a change in the depletion depth of the nanowires, the change in the depletion depth being due to an adsorbate induced change in the potential on the gold nanoparticles on the surface of the nanowires.


Journal of Porous Materials | 2012

Synthesis of nanoporous platinum thin films and application as hydrogen sensor

Aditya Abburi; Nathan Abrams; Wei Jiang Yeh

A nanoporous platinum (np-Pt) thin film based hydrogen sensor was fabricated and studied. The np-Pt thin films were fabricated through a method of chemical dealloying and coarsening starting from a CuPt alloy. The alloy thin films of CuxPt1−x were deposited by sputtering copper and platinum at the same time. The dealloying process completely removed the copper from the film. We demonstrate a method to control the porosity of np-Pt by a method of coarsening. Scanning electron microscopy confirmed the presence of porosity with size ranging from a few nanometers to tens of nanometers. A sensor device with four electrodes was fabricated on the np-Pt thin films using a stainless steel mask and by sputtering copper. The electrical characteristics of the sensor exhibit marked sensitivity or current changes in the presence of hydrogen. The results demonstrate that np-Pt thin films configured as a gas sensor have high sensitivity to hydrogen.


Journal of Nanomaterials | 2011

ZnO and MgZnO nanocrystalline flexible films: optical and material properties

Jesse Huso; John L. Morrison; Hui Che; Jency Pricilla Sundararajan; Wei Jiang Yeh; David N. McIlroy; Thomas J. Williams; Leah Bergman

An emerging material for flexible UV applications is MgxZn1-xO which is capable of tunable bandgap and luminescence in the UV range of ∼3.4 eV-7.4 eV depending on the composition x. Studies on the optical and material characteristics of ZnO and Mg0.3Zn0.7O nanocrystalline flexible films are presented. The analysis indicates that the ZnO and Mg0.3Zn0.7O have bandgaps of 3.34 eV and 4.02 eV, respectively. The photoluminescence (PL) of the ZnO film was found to exhibit a structural defect-related emission at ∼3.316 eV inherent to the nanocrystalline morphology. The PL of the Mg0.3Zn0.7O film exhibits two broad peaks at 3.38 eV and at 3.95 eV that are discussed in terms of the solubility limit of the ZnO-MgO alloy system. Additionally, external deformation of the film did not have a significant impact on its properties as indicated by the Raman LO-mode behavior, making these films attractive for UV flexible applications.


IEEE Sensors Journal | 2012

Temperature and Pore Size Dependence on the Sensitivity of a Hydrogen Sensor Based on Nanoporous Platinum Thin Films

Aditya Abburi; Wei Jiang Yeh

Nanoporous Pt thin films were prepared by co-sputtering Cu and Pt, followed by dealloying and coarsening. The size of the pores was controlled by the coarsening temperature. The nanoporous Pt thin films had pores ranging from a few nanometers to 35 nm. A resistance transient method was used to measure the sensitivity of these thin films in different hydrogen concentrations using air as the carrier gas. The effect of temperature and pore size on the sensitivity and response time were studied. A sensitivity of 3.5% was obtained for 1000 ppm of hydrogen at room temperature for the largest fabricated pore size of 35 nm. The fabricated sensors showed quick response and repeatability in their sensing mechanism.


International Journal of Modern Physics B | 2005

FABRICATION OF UNIFORM ARRAY OF NANO-DOTS AND ITS APPLICATIONS

Wei Jiang Yeh; Bo Cheng; Kun Yang

We have developed a novel technique to fabricate extremely uniform arrays of nano-sized dots. Regular arrays of nanometer-sized metallic dots are obtianed by magnetron sputtering deposition through a nanochannel glass replica mask. The platinum replica masks are fabricated using thin film deposition on an etched nanochannel glass and contain hexagonally patterned uniform voids with diameters as small as 50 nanometers. The metallic dot density can be as high as 5×1011 per square centimeter. The magnetic properties of Ni and Co dot arrays have been studied by a Alternating Gradient Magnetometer. The magnetic dot array can be used as pinning centers for superconductors and also can be used as the discrete magnetic media for magnetic recording.


International Journal of Modern Physics B | 2003

Numerical Calculation of Interaction Between the Ferromagnetic Dots and Vortices

Bo Cheng; Tony Ragsdale; Wei Jiang Yeh

Enhancing the pinning force in high-Tc superconductors can be achieved by externally introduced periodic magnetic dots. We have numerically calculated the interaction between the magnetic dot and the vortex in high-Tc superconductors. The London equation is used to generate two-dimensional vortex lattice. In the matching condition, we calculate the attraction force between the magnetic dots and vortices at various conditions. It is found that the magnitude of the pinning from the dots is compatible with the intrinsic pinning force of YBCO thin film materials.


Journal of Superconductivity and Novel Magnetism | 2008

Interaction between the Ferromagnetic Dots and Vortices: Numerical Calculation and Experimental Results

Bo Cheng; Tony Ragsdale; Wei Jiang Yeh


MRS Proceedings | 2012

ZnS x O 1-x Films Grown on Flexible Substrates

Jesse Huso; Hui Che; John L. Morrison; Dinesh Thapa; Michelle Huso; Stanley Rhodes; Brianna Blanchard; Wei Jiang Yeh; M. D. McCluskey; Leah Bergman


Journal of materials science & engineering | 2011

Fabrication of Bulk, Self-bias Barium Ferrites for Microwave Circulator Applications

Carla Blengeri; Tom Casad; Aditya Abburi; David N. McIlroy; Wei Jiang Yeh; Jeffrey L. Young


Bulletin of the American Physical Society | 2011

Temperature and Pore Size Dependence of a Nanoporous Platinum Based Hydrogen Senor

Aditya Abburi; Harold Fairweather Jr.; Wei Jiang Yeh

Collaboration


Dive into the Wei Jiang Yeh's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge