title: Thermal Delocalization of Excitons in GaAs/AlGaAs Quantum Well Tube Nanowires.
abstract: We use temperature-dependent photoluminescence (PL), photoluminescence imaging, and time-resolved photoluminescence measurements to gain insights into the localization of excitons in single 2 nm GaAs/AlGaAs quantum well tube nanowires. PL spectra reveal the coexistence of localized and delocalized states at low temperatures, with narrow quantum dot-like emission lines on the high energy side of a broad emission band, and delocalized states on the low energy side. We find that the high energy QD-like emissions are metastable, disappearing at higher temperatures with only delocalized states (quantum well tube ground states) surviving. By comparing temperature- and time-dependent PL, we develop a theoretical model which provides insights into the confinement potentials and relaxation dynamics which localize the excitons in these quantum well tube nanowires.
authors.affiliation: Department of Physics, University of Cincinnati , Cincinnati, Ohio 45221-0011, United States.
authors.forename: Teng
authors.initials: T
authors.lastname: Shi
authors.affiliation: Department of Physics, University of Cincinnati , Cincinnati, Ohio 45221-0011, United States.
authors.forename: Howard E
authors.initials: HE
authors.lastname: Jackson
authors.affiliation: Department of Physics, University of Cincinnati , Cincinnati, Ohio 45221-0011, United States.
authors.forename: Leigh M
authors.initials: LM
authors.lastname: Smith
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Nian
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: H Hoe
authors.initials: HH
authors.lastname: Tan
authors.affiliation: Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University , Canberra, ACT 2601, Australia.
authors.forename: Chennupati
authors.initials: C
authors.lastname: Jagadish
keywords: Nanowires; heterostructures; quantum dots; quantum well