Ordering and Absolute Energies of theL6candX6cConduction Band Minima in GaAs

Abstract

Resolved critical point structures in Schottky-barrier electroreflectance spectra of $\mathrm{Ga}3d^V$-$s{p}^3$ conduction band transitions in the 20-22-eV range provide a direct proof that the $L_6^{}{}_{}{}^C$ equivalent minima lie approximately 170±30 meV below the $X_6^{}{}_{}{}^C$ minima in GaAs. This ordering, opposite to that assumed and apparently supported by previous experiments, is in fact consistent with these experiments and provides natural explanations for many formerly puzzling features of GaAs.