CONFINED EXCITONS IN CORRUGATED GAAS/ALAS SUPERLATTICES

A strong modification of excitons is observed in corrugated GaAs/AlAs superlattice structures directly grown by molecular-beam epitaxy on (31 1) A GaAs substrates. The increased exciton continuum energies and the phonon sidebands of the exciton luminescence point out the length scale of lateral localization. The observation of hot-exciton luminescence up to high temperatures and excitation intensities reveals the high stability of the confined excitons. The pronounced degree of optical anisotropy and the anisotropic optical alignment of the excitons is in agreement with a lateral potential introduced by the periodically corrugated interfaces.