Electrical properties of undoped GaN films grown by maskless epitaxial lateral overgrowth

A. Y. Polyakov, Dae Woo Jeon, In Hwan Lee, N. B. Smirnov, A. V. Govorkov, E. A. Kozhukhova, E. B. Yakimov

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Electrical properties, deep traps spectra, microcathodoluminescence (MCL) spectra measurements, MCL imaging, and electron beam induced current (EBIC) imaging were performed for undoped GaN films grown by metalorganic chemical vapor deposition using maskless epitaxial lateral overgrowth on basal plane sapphire. The films showed a low dislocation density of ∼108 cm-2 in the laterally overgrown wings and an order of magnitude higher dislocation density in vertical growth seed regions, as determined by MCL and EBIC imaging. The polarity of EBIC signal measurements and the room temperature capacitance-voltage characteristics suggested that the high-dislocation-density seed regions were high-resistivity p-type, with the Fermi level pinned near Ev + 0.4 eV, as determined by admittance spectroscopy. The wing regions were n-type, with low residual donor concentration of some 1014 cm-3 near the surface. The donor concentration further decreased upon movement towards the sapphire substrate. Some possible explanations of the observed effects are discussed.

Original languageEnglish
Article number083712
JournalJournal of Applied Physics
Volume113
Issue number8
DOIs
Publication statusPublished - 2013 Feb 28

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Electrical properties of undoped GaN films grown by maskless epitaxial lateral overgrowth'. Together they form a unique fingerprint.

  • Cite this

    Polyakov, A. Y., Jeon, D. W., Lee, I. H., Smirnov, N. B., Govorkov, A. V., Kozhukhova, E. A., & Yakimov, E. B. (2013). Electrical properties of undoped GaN films grown by maskless epitaxial lateral overgrowth. Journal of Applied Physics, 113(8), [083712]. https://doi.org/10.1063/1.4793630