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

We used a broadband, atomic-force-microscope-based, scanning microwave microscope (SMM) to probe the axial dependence of the charge depletion in a p-n junction within a gallium nitride nanowire (NW). SMM enables the visualization of the p-n junction location without the need to make patterned electrical contacts to the NW. Spatially resolved measurements of S{sub 11}{sup ′}, which is the derivative of the RF reflection coefficient S{sub 11} with respect to voltage, varied strongly when probing axially along the NW and across the p-n junction. The axial variation in S{sub 11}{sup ′}  effectively mapped the asymmetric depletion arising from the doping concentrations on either side of the junction. Furthermore, variation of the probe tip voltage altered the apparent extent of features associated with the p-n junction in S{sub 11}{sup ′} images.
Authors:
 [1] ;  [2] ; ; ; ; ; ;  [1] ;  [1] ;  [2] ;  [3]
  1. Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)
  2. (United States)
  3. Information Technology Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)
Publication Date:
OSTI Identifier:
22303906
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 26; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ASYMMETRY; ATOMIC FORCE MICROSCOPY; ELECTRIC CONTACTS; ELECTRIC POTENTIAL; GALLIUM NITRIDES; IMAGES; MICROWAVE RADIATION; NANOWIRES; P-N JUNCTIONS; REFLECTION