Y.S. Huang, H. Qiang, et al.
Journal of Applied Physics
The optical constants ε(E)=ε 1(E) +iε 2(E) of unintentionally doped In 0.53Ga 0.47As lattice matched to InP have been measured at 300 K using spectral ellipsometry in the range of 0.4 to 5.1 eV. The ε(E) spectra displayed distinct structures associated with critical points at E 0 (direct gap), spin-orbit split E 0+Δ 0 component, spin-orbit split E 1, E 1+Δ 1, E 0′ feature, as well as E 2. The experimental data over the entire measured spectral range (after oxide removal) has been fit using the Holden model dielectric function [Holden et al., Phys. Rev. B 56, 4037 (1997)], plus a Kramers-Kronig consistent correction, described in this work, that improves the fitting at low energies. This extended model is based on the electronic energy-band structure near these critical points plus excitonic and band-to-band Coulomb-enhancement effects at E 0, E 0+Δ 0, the E 1, E 1+Δ 1, doublet. In addition to evaluating the energies of these various band-to-band critical points, information about the binding energy (R 1) of the two-dimensional exciton related to the E 1, E 1+Δ 1 critical points was obtained. The value of R 1 was in good agreement with effective mass/kṡp theory. The ability to evaluate R 1 has important ramifications for first-principles band-structure calculations that include exciton effects at E 0, E 1, E 2 [M. Rohlfing and S. G. Louie, Phys. Rev. Lett. 81, 2312 (1998); S. Albrecht et al., Phys. Rev. Lett. 80, 4510 (1998)]. © 2002 American Institute of Physics. © 2002 American Institute of Physics.
Y.S. Huang, H. Qiang, et al.
Journal of Applied Physics
X. Yin, Xinxin Guo, et al.
Applied Physics Letters
H. Qiang, Fred H. Pollak, et al.
Surface Science
A. Bond, P. Parayanthal, et al.
Cambridge Symposium 1983