Valence-band splitting in orderedGa0.5In0.5P measured by polarized photoluminescence excitation spectroscopy

The spontaneous long-range-order-induced splitting of the valence band of ${\mathrm{Ga}}_{0.5}$ ${\mathrm{In}}_{0.5}$P is studied by polarized near-gap-excited photoluminescence and photoluminescence excitation. The results allow a direct determination of the size of the valence-band splitting and the relative ordering of the resultant states. Values obtained for the splitting are compared with recent calculations.