Strong optical nonlinearity in strain-induced laterally ordered In0.4Ga0.6As quantum wires on GaAs „311...A substrate

Strain-induced laterally ordered In0.4Ga0.6As on 311 A GaAs template quantum wires have been fabricated and identified with cross-section transmission electron microscopy technique to be of average length 1 m, and on average width and height of 23 and 2 nm, respectively, under InGaAs coverage of six monolayers. The photoluminescence spectrum of a sample demonstrates unusually strong optical nonlinearity even at moderate excitation densities. The excitonic peak energy blueshifts by 25 meV without essential contribution of the quantum wire excited states at elevating excitation density. Strong decrease of the polarization anisotropy and increase of the energy of excitonic photoluminescence are attributed to a combined action of the phase-space filling effects and the screening of the internal piezoelectric field by free carriers. © 2005 American Institute of Physics. DOI: 10.1063/1.2039999