Beyond spatial correlation effect in micro-Raman light scattering: An example of zinc-blende GaN/GaAs hetero-interface

Journal Article (Journal Article)

Spatially resolved Raman light scattering experiments were performed on a zinc-blende GaN/GaAs heterostructure with confocal micro-Raman scattering technique under the backscattering geometric configuration. By varying the illumination spot locations across the heterostructure interface, we found that the Raman light scattering spectral features change remarkably. The interface effect on the GaAs substrate manifested as a much broader lineshape of the transverse optical (TO) phonon mode. Two kinds of broadening mechanisms, namely, spatial correlation induced wave-vector relaxation effect and lattice-mismatch strain + compositional intermixing effect, have been identified. The former leads to the broadening of the TO mode at the low-energy side, whereas the latter accounts for the broadening at the high-energy side. The diffuse light scattering from the highly defective nucleation layer of GaN was found to produce a broad scattering background of the GaN TO mode. The methodology and conclusions of the present work could be applicable to Raman spectroscopic studies on other material interfaces.

Full Text

Duke Authors

Cited Authors

  • Ning, JQ; Zheng, CC; Zheng, LX; Xu, SJ

Published Date

  • August 21, 2015

Published In

Volume / Issue

  • 118 / 7

Electronic International Standard Serial Number (EISSN)

  • 1089-7550

International Standard Serial Number (ISSN)

  • 0021-8979

Digital Object Identifier (DOI)

  • 10.1063/1.4928618

Citation Source

  • Scopus