Micro-Photoluminescence Study at Room Temperature of Sidewall Quantum Wires Formed on Patterned GaAs (311)A Substrates by Molecular Beam Epitaxy

Abstract

Lateral quantum wires are grown by molecular beam epitaxy of GaAs/(AlGa)As multilayer structures on patterned GaAs (311)A substrates along the sidewall of 15–20 nm heigh mesa stripes oriented along [01–1]. The wire formation relies on the preferential migration of Ga atoms from the mesa top and bottom toward the sidewall. The quantum wires having a lateral width of ∼50 nm are characterized by micro-photoluminescence spectroscopy between 8 K and room temperature. In the whole temperature regime the quantum wire exhibits a clear luminescence peak, well separated from the quantum well peak at the mesa top and bottom forming the lateral barriers. Micro-photoluminescence linescans reveal the strong spatial confinement of the photogenerated carriers even at room temperature.