InGaAs quantum well wires grown on patterned GaAs substrates

Abstract

Strained InGaAs/GaAs quantum well wires have been grown on 2300 Å 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.