Exciton localization in corrugated GaAs/AlAs superlattices grown on (311) GaAs substrates

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Abstract
Using temperature-dependent photoluminescence we have studied the exciton-localization effect in GaAs/AlAs corrugated superlattices (CSL’s) grown on (311) GaAs substrates. In this structure, the creation of deeper localized states below the ground states by the perturbation of the corrugated interfaces is suggested. This effect is supposed to lead to the redshift of the exciton emission relative to that in the (100) reference sample at low temperature. In type-II CSL’s the local potential minima in the Γ point of GaAs serve as the initial states of the Γ transition through the resonant injection of electrons from the X point of AlAs to the localized states in the Γ point of GaAs, resulting in the observed strong X-band emission up to room temperature, but with a Γ-like behavior in the temperature dependences of the linewidth and the exciton emission energy.