We have evaluated the Burstein-Moss (BM) shift at 300 K in seven samples of
n-In0.53Ga0.47As (1.3 x10(16)less than or equal ton less than or equal to3
.9x10(19)cm(-3)) lattice matched to InP using spectral ellipsometry in the
range of 0.4-5.1 eV. The data have been fitted over the entire spectral ran
ge to a model reported by Holden et al. [in Thermphotovolmic Generation of
Electricity, edited by T. J. Coutts, J. P. Brenner, and C. S. Allman, AIP C
onf. Proc. No. 460 (AIP, Woodbury, NY, 1999), p. 39], based on the electron
ic energy-band structure near critical points plus relevant discrete and co
ntinuum excitonic effects. A Fermi-level filling factor in the region of th
e fundamental gap has been used to account for the BM effect. While our dat
a exhibit nonparabolic effects, with a blueshift of 415 meV for the most hi
ghly doped sample, we did not observe the Fermi-level saturation at 130 meV
for n greater than or equal to 10(19)cm(-3) reported by Tsukernik et al. [
Proceedings of the 24th International Conference on the Physics of Semicond
uctors, Jerusalem, 1998; edited by D. Gershoni (World Scientific, Singapore
, 1999)]. Our BM displacements are in agreement with a modified full-potent
ial linearized augmented-plane-wave calculation [G. W. Charache et al., J.
Appl. Phys. 86, 452 (1949)] plus possible band-gap-reduction effects.