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Determination of surface barrier height and surface state density in GaN films grown on sapphire substrates

Published

Author(s)

Seong-Eun Park, Joseph Kopanski, Youn-Seon Kang, Larry Robins, Hyun-Keel Shin

Abstract

Photoreflectance (PR) modulation spectroscopy was performed to investigate surface properties of GaN films grown on sapphire substrates. From the period of the Franz-Keldysh oscillations, the surface electric field across the GaN space charge region was found to be (197.3 '' 11.4) kV/cm, which corresponds to a surface state density of 1.0 x 10e12 cm^-2. A surface barrier height (SBH) of 0.71 eV was determined by fitting the dependence of the PR intensities on pump beam power density. We suggest that a deep level is formed at 2.68 eV above the GaN valence band edge due to the large density of surface states.
Proceedings Title
MRS Electronic Proceedings
Conference Dates
November 29-December 3, 2004
Conference Location
Boston, MA, USA

Keywords

GaN, Photoreflectance, Surface electronic properties

Citation

Park, S. , Kopanski, J. , Kang, Y. , Robins, L. and Shin, H. (2005), Determination of surface barrier height and surface state density in GaN films grown on sapphire substrates, MRS Electronic Proceedings, Boston, MA, USA (Accessed June 21, 2024)

Issues

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Created March 23, 2005, Updated October 12, 2021