INGAAS QUANTUM-WELL WIRES GROWN ON PATTERNED GAAS SUBSTRATES

Strained InGaAs/GaAs quantum well wires have been grown on 2300 angstrom period gratings etched into GaAs substrates. Both conventional molecular beam epitaxy and migration-enhanced epitaxy have been used as growth techniques. The low-temperature photoluminescence from the quantum well wires was compared to the photoluminescence from a planar quantum well sample grown simultaneously. The planar samples showed a sharp single peak, whereas the patterned samples displayed two peaks. The samples grown by conventional molecular beam epitaxy had two fairly broad, overlapping peaks of comparable intensity. The samples grown by migration-enhanced epitaxy had two distinct peaks, with one peak an order of magnitude larger than the other. Polarization-dependent photoluminescence was performed on the migration-enhanced epitaxy grown samples. The larger of the two peaks on the patterned sample showed a 21% linear polarization dependence, while the other peak showed unpolarized emission. In addition, the quantum well grown on the unpatterned substrate exhibited unpolarized emission.