Size and composition dependence of photoluminescence from In/sub x/Ga/sub 1-x/As quantum wires

Abstract

InGaAs quantum wires (QWRs) are grown on GaAs vicinal (110) surfaces with the giant step by MBE. These QWRs are induced by thickness modulation at coherently aligned giant step edges. Crosssectional transmission electron microscope (TEM) observation shows that the In,Gal-,As is thicker at step edges than on terrace regions, resulting in QWRs formation. Photoluminescence (PL) measurements reveal that the PL peak of In,Gal-,As QWRs shift to lower energies compared to those of In,Gal-,As quantum well (QWL) on GaAs (100) substrates grown at the same time. The PL of these In,Gal.,As QWRs exhibited a strong polarization anisotropy which increased with increasing InAs composition. PL peak positions of thick In,Gal-,As QWRs shift to higher energies with increasing InAs composition, and to lower energies with increasing growth thickness. PL peak positions of thin QWRs shift higher energies with increasing InAs composition due to reduced effective mass.