Band gap renormalization and Burstein-Moss effect in silicon- and germanium-doped wurtzite GaN up to 1020 cm-3
M. Feneberga, S. Osterburga, K. Langea, C. Lidiga, B. Garkea, R. Goldhahna, E. Richterb, C. Netzelb, M.D. Neumannc, N. Esserc, S. Fritzea, H. Wittea, J. Bläsinga, A. Dadgara, and A. Krosta
Published in:
Phys. Rev. B, vol. 90, no. 075203 (2014).
Abstract:
The interplay between band gap renormalization and band filling (Burstein-Moss effect) in n-type wurtzite GaN is investigated. For a wide range of electron concentrations up to 1.6×1020 cm-3 spectroscopic ellipsometry and photoluminescence were used to determine the dependence of the band gap energy and the Fermi edge on electron density. The band gap renormalization is the dominating effect up to an electron density of about 9×1018 cm-3; at higher values the Burstein-Moss effect is stronger. Exciton screening, the Mott transition, and formation of Mahan excitons are discussed. A quantitative understanding of the near gap transition energies on electron density is obtained. Higher energy features in the dielectric functions up to 10 eV are not influenced by band gap renormalization.
a Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany
b Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, 12489 Berlin, Germany
c Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Albert-Einstein-Straße 9, 12489 Berlin, Germany
PACS number(s):
78.20.Ci, 71.35.-y, 71.45.Gm
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