Influence of strain and quantum confinement on the optical properties of InGaAs/GaAs V-groove quantum wires

We report on the impact of quantum confinement and strain effects on the op tical properties of state-of-the-art, densely stacked, In0.15Ga0.85As/GaAs V-groove quantum wires. High uniformity and efficient carrier capture lead to narrow (6 meV) and intense emission from the wires. Large optical polari zation anisotropy is obtained thanks to the combined effects of lateral qua ntum confinement and triaxial strain. Band filling in the fundamental subba nd occurs at a modest carrier density (similar to 9x10(5) cm(-1)), and is a ccompanied by a small spectral blueshift of the emission. Several sharp exc itonic resonances associated with two dimensionally confined subbands of do minant heavy-hole character are observed in photoluminescence excitation sp ectroscopy, together with a remarkably small Stokes shift (3 meV). The subb and separations (similar to 24 meV) are nearly independent of the wire thic kness, as the nonuniform Indium composition across the structure is found t o dominate the lateral confinement for thick wires. Such strained quantum w ires are promising for the realization of advanced nanostructure devices. ( C) 2000 American Institute of Physics. [S0021-8979(00)04213-4].