QUASI-PERIODIC MICROFACETS ON THE SURFACE OF ALGAAS GAAS QUANTUM-WELLSTRUCTURES GROWN BY MOLECULAR-BEAM EPITAXY ON (311)A HIGH-INDEX SUBSTRATES/

Standard molecular beam epitaxy is used to demonstrate the growth feas ibility and reproducibility on the formation of microfacet array on th e top surface of higher-index (311)A quantum well structures. The quas iperiodic microfacet array was characterized by atomic force microscop y and was observed to be along the <[(2)over bar 33]> direction, where as for the (100) reference sample the microscopic surface morphology p resented the terraces formation. We have used photoluminescence to cha racterize the optical properties of the samples. The observed redshift of the luminescence from the (311)A sample, in relation to the (100) reference sample, was correlated with the existence of a lateral confi nement potential induced by the period of faceting in this structure. The comparative analysis based on photoluminescence measurements have also shown the higher quality and the lower impurity incorporation for the (311)A oriented samples. (C) 1996 American Vacuum Society.