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Title: Structural, electrical, and optical characterization of coalescent p-n GaN nanowires grown by molecular beam epitaxy

The electrical, structural, and optical properties of coalescent p-n GaN nanowires (NWs) grown by molecular beam epitaxy on Si (111) substrate are investigated. From photoluminescence measurements the full width at half maximum of bound exciton peaks AX and DA is found as 1.3 and 1.2 meV, respectively. These values are lower than those reported previously in the literature. The current-voltage characteristics show the rectification ratio of about 10{sup 2} and the leakage current of about 10{sup −4} A/cm{sup 2} at room temperature. We demonstrate that the thermionic mechanism is not dominant in these samples and spatial inhomogeneties and tunneling processes through a ∼2 nm thick SiN{sub x} layer between GaN and Si could be responsible for deviation from the ideal diode behavior. The free carrier concentration in GaN NWs determined by capacitance-voltage measurements is about 4 × 10{sup 15 }cm{sup −3}. Two deep levels (H190 and E250) are found in the structures. We attribute H190 to an extended defect located at the interface between the substrate and the SiN{sub x} interlayer or near the sidewalls at the bottom of the NWs, whereas E250 is tentatively assigned to a gallium-vacancy- or nitrogen interstitials-related defect.
Authors:
 [1] ; ; ;  [2] ;  [3]
  1. Technische Universität Dresden, 01062 Dresden (Germany)
  2. Institute of Physics Polish Academy of Sciences, al. Lotnikow 32-46, 02-668 Warsaw (Poland)
  3. Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw (Poland)
Publication Date:
OSTI Identifier:
22493028
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 22; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CARRIERS; COALESCENCE; CONCENTRATION RATIO; DEFECTS; ELECTRIC POTENTIAL; ELECTRICAL PROPERTIES; GALLIUM; GALLIUM NITRIDES; INTERSTITIALS; LEAKAGE CURRENT; MEV RANGE; MOLECULAR BEAM EPITAXY; NANOWIRES; NITROGEN; OPTICAL PROPERTIES; PHOTOLUMINESCENCE; P-N JUNCTIONS; SILICON; TEMPERATURE RANGE 0273-0400 K; TUNNEL EFFECT; VACANCIES