Alloy segregation, quantum confinement, and carrier capture in self-ordered pyramidal quantum wires
2006 (English)In: Nano Letters, ISSN 1530-6984, Vol. 6, no 5, 1036-1041 p.Article in journal (Refereed) Published
The structure and photoluminescence (PL) characteristics of AlGaAs quantum wires self-formed by metallorganic vapor-phase epitaxy in inverted tetrahedral pyramids are reported. Capillarity-driven Ga-Al segregation yields vertical quantum wires (VQWRs) at the center of the pyramid, connected to more-weakly segregated vertical quantum wells (VQWs) formed along their wedges. The segregation is evidenced in transmission electron microscope images and in the PL spectra of these structures. Transitions between quantum-confined electron and hole states in the VQWR are identified in the micro-PL spectra with energies in good agreement with model calculations. The temperature dependence of the micro-PL spectra clearly reveals efficient carrier capture into the VQWR from the VQWs, particularly at an intermediate temperature range ( [similar to] 100 K) where carrier mobility is enhanced. These wires offer new possibilities for tailoring the confinement potential in one-dimensional systems.
Place, publisher, year, edition, pages
2006. Vol. 6, no 5, 1036-1041 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-26510DOI: 10.1021/nl060066dOAI: oai:DiVA.org:uu-26510DiVA: diva2:54284