Quantization effects of InGaAs/InP-quantum wires grown on patterned substrates

We fabricated In_xGa_1-xAs quantum wires on V-grooved InP substrates using low pressure metal organic chemical vapor deposition. The InGaAs layers were grown directly onto the patterned substrate forming single crescent shaped quantum wires in the groove tips. We applied transmission electron microscopy to reveal the structural properties of the samples and performed polarization and excitation dependent photoluminescence, and spatially resolved cathodoluminescence to examine the optical properties. Based on a comparison between optical measurements and an eight-band k&oarr;·p&oarr; band-structure calculation we identified that nominally lattice matched grown wires are strained due to increased indium content of up to x≈0.7. The electron states are confined in the wire center and spatially separated from the hole states confined at the edges. The optical experiments unambiguously demonstrate the one-dimensional character of the quantum wires. Variations in the InGaAs layer thickness have strong impact on the optical properties