Evidence of satellite valley position in GaN by photoexcited field emission spectroscopy Article

Yilmazoglu, O, Pavlidis, D, Hartnagel, HL et al. (2008). Evidence of satellite valley position in GaN by photoexcited field emission spectroscopy . JOURNAL OF APPLIED PHYSICS, 103(11), 10.1063/1.2937257

cited authors

  • Yilmazoglu, O; Pavlidis, D; Hartnagel, HL; Evtukh, A; Litovchenko, V; Semenenko, N

authors

abstract

  • GaN field emitter rods with nanometer diameter were fabricated by photoelectrochemical etching on a n+ -GaN substrate. Their electron field emission properties were investigated under ultraviolet (UV) illumination. The Fowler-Nordheim plots of the emission current show different slopes for nonilluminated and UV illuminated devices. A model based on the electron emission from valleys having different specific electron affinities is proposed to explain the experimental results. In the absence of illumination, the GaN rods are almost fully depleted and emission takes place only from the lower valley. Upon UV illumination and presence of a high electric field at the emitter tip, the upper valley of the conduction band appears to be occupied by electrons generated at the valence band. The energy difference between the lower and upper valleys was determined to be 1.15 eV and is in good agreement with formerly published theoretical and measured values. © 2008 American Institute of Physics.

publication date

  • June 20, 2008

published in

Digital Object Identifier (DOI)

volume

  • 103

issue

  • 11