ABRUPT HETEROJUNCTIONS OF ALGAAS/GAAS QUANTUM-WELLS GROWN ON (111)A GAAS SUBSTRATES BY MOLECULAR-BEAM EPITAXY

Morphologies and interface abruptness of AlGaAs/GaAs on (111)A GaAs substrates are studied using single quantum well (SQW) structures consisting of five GaAs layers of variable thickness. They are grown on exactly (111)A GaAs and (111)A GaAs surfaces that are misoriented towards the [100] direction by 1-degrees, 3-degrees, and 5-degrees. The abruptness of AlGaAs/GaAs heterojunctions grown on GaAs (111)A surfaces has been evaluated by photoluminescence (PL) intensity measurements. It has been demonstrated that the PL peak wavelengths for SQW structures on the exactly and 5-degrees misoriented (111)A surfaces agree with the values calculated with the effective mass of the heavy hole of m*hh = 0.9m0. The abruptness of SQW structures on these surfaces is estimated as less than one monolayer from full width at half maximum(FWHM) values.