Article thumbnail

Residual donors in wurtzite GaN homoepitaxial layers and heterostructures

By G. Neu, M. Teisseire-Doninelli, C. Morhain, F. Semond, N. Grandjean, B. Beaumont, E. Frayssinet, W. Knap, A. M. Witowski, M. L. Sadowski, M. Leszczynski and P. Prystawko


Shallow donors in GaN epilayers grown by metalorganic chemical vapour deposition (MOCVD) and by molecular beam epitaxy (MBE) on sapphire, SiC and GaN substrates have been studied by selectively excited photoluminescence (SPL) and far-infrared (FIR) absorption. The spectroscopic studies of neutral donor bound excitons allow us to determine the (DX)-X-0 rotational excited state spectra in a large domain of tensile and compressive strain fields depending on the substrates used for the growth. The energy transitions between the ground state and the n = 2 states of residual donors are determined from the spectra of the two-electron replica of (DX)-X-0 lines in accordance with resonant electronic Raman scattering results. The comparison between FIR results and the two-electron spectroscopy shows, that silicon is the main residual donor (E-d = 30.4 meV in strain-free samples) in both MOVPE and MBE layers. A second unknown donor (E-d = 31.8 meV) is frequently found in GaN/SiC grown by MOCVD. A third deeper level (E-d = 33.1 meV) is rarely detected by two-electron spectroscopy but could be associated with a weak neutral-donor bound exciton shifted down by 0.9 meV from the main Si-Ga related (DX)-X-0 line in MBE hornoepitaxial layers

Publisher: 'Wiley'
Year: 2010
DOI identifier: 10.1002/pssb.200301524
OAI identifier:
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • (external link)
  • Suggested articles

    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.