U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Joel Weber (Assoc)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 38 of 38

GaN nanowire coated with atomic layer deposition of tungsten: a probe for near-field scanning microwave microscopy

September 25, 2014
Author(s)
Joel Weber, Paul T. Blanchard, Aric Sanders, Jonas Gertsch, Steven George, Samuel Berweger, Atif A. Imtiaz, Thomas Mitchell (Mitch) Wallis, Kris A. Bertness, Pavel Kabos, Norman A. Sanford, victor bright
We report on the fabrication of a GaN nanowire probe for near-field scanning microwave microscopy. The probe has a capacitive resolution of 0.03 fF, surpassing that of a commercial Pt tip. Imaging of MoS2 sheets found the probe to be immune to surface

Imaging the p-n junction in a gallium nitride nanowire with a scanning microwave microscope

July 2, 2014
Author(s)
Atif A. Imtiaz, Thomas M. Wallis, Joel C. Weber, Kevin J. Coakley, Matthew D. Brubaker, Paul T. Blanchard, Kristine A. Bertness, Norman A. Sanford
We used a broadband, atomic-force-microscope-based, scanning microwave microscope (AFM-SMM) to probe the axial dependence of the depletion in a GaN nanowire (NW) p-n junction structure. The NWs were c-axis oriented and grown by molecular beam epitaxy. The

Gallium Nitride Nanowire Probe for Near-Field Scanning Microwave Microscopy

January 15, 2014
Author(s)
Joel C. Weber, Paul T. Blanchard, Aric W. Sanders, Atif A. Imtiaz, Thomas M. Wallis, Kevin J. Coakley, Kristine A. Bertness, Pavel Kabos, Norman A. Sanford, Victor M. Bright
We report on the fabrication of a GaN nanowire probe for near-field scanning microwave microscopy. A single nanowire was Pt-bonded to a commercial Si cantilever prior to evaporation of a Ti/Al coating to provide a microwave signal pathway. Testing over a

A near-field scanning microwave microscope for characterization of inhomogeneous photovoltaics

August 10, 2012
Author(s)
Joel C. Weber, Kristine A. Bertness, John B. Schlager, Norman A. Sanford, Atif A. Imtiaz, Thomas M. Wallis, Pavel Kabos, Kevin J. Coakley, Victor Bright, Lorelle M. Mansfield
We present a near field scanning microwave microscope (NSMM) optimized for imaging photovoltaic samples. Our system incorporates a cut Pt-Ir tip inserted into an open ended coaxial cable to form a weak resonator, allowing the microwave reflection S11

Microwave near-field probes for photovoltaic applications

June 19, 2011
Author(s)
Joel C. Weber
The photoresponse of three different photovoltaic Cu(In, Ga)Se 2 (CIGS) samples as well as GaAs and silicon bulk samples is measured using near-field scanning microwave microscopy (NSMM). Modeling predicts light-dependent conductivity values for bulk

Application of Microwave Scanning Probes to Photovoltaic Materials

June 20, 2010
Author(s)
Kristine A. Bertness, John B. Schlager, Norman A. Sanford, Atif A. Imtiaz, Thomas M. Wallis, Joel C. Weber, Pavel Kabos, Lorelle M. Mansfield
We demonstrate that near field scanning microwave microscopy (NSMM) can be used to detect photoresponse in photovoltaic materials with potential for submicrometer resolution. In this approach, a radio-frequency scanning tunneling microscopy (RF-STM) tip is