By a News Reporter-Staff News Editor at Journal of Engineering -- Researchers detail new data in Nanowires. According to news reporting from Montpellier, France, by VerticalNews journalists, research stated, "Crystal-phase engineering has emerged as a novel method of bandgap engineering, made feasible by the high surface-to-volume ratio of nanowires. There remains intense debate about the exact characteristics of the band structure of the novel crystal phases, such as wurtzite GaAs, obtained by this approach."
The news correspondents obtained a quote from the research from the University of Montpellier, "We attack this problem via a low-temperature angle-dependent magneto-photoluminescence study of wurtzite/zinc-blende quantum disks in single GaAs nanowires. The exciton diamagnetic coefficient is proportional to the electron-hole correlation length, enabling a determination of the spatial extent of the exciton wave function in the plane and along the confinement axis of the crystal-phase quantum disks. Depending on the disk nature, the diamagnetic coefficient measured in Faraday geometry ranges between 25 and 75 mu eV/T-2. For a given disk, the diamagnetic coefficient remains constant upon rotation of the magnetic field. Along with our envelope function calculation accounting for excitonic effects, we demonstrate that the electron effective mass in wurtzite GaAs quantum disks is heavy, mostly isotropic and results from mixing of the two lower-energy conduction bands with Gamma(7) and Gamma(8) symmetries. Finally, we discuss the implications of the results of the angle dependent magneto-luminescence for the likely symmetry of the exciton states."
According to the news reporters, the research concluded: "This work provides important insight in the band structure of wurtzite GaAs for future nanowire-based polytypic bandgap engineering."
For more information on this research see: Three-Dimensional Magneto-Photoluminescence as a Probe of the Electronic Properties of Crystal-Phase Quantum Disks in GaAs Nanowires. Nano Letters, 2013;13(11):5303-5310. Nano Letters can be contacted at: Amer Chemical Soc, 1155 16TH St, NW, Washington, DC 20036, USA. (American Chemical Society - www.acs.org; Nano Letters - www.pubs.acs.org/journal/nalefd)
Our news journalists report that additional information may be obtained by contacting P. Corfdir, University of Montpellier, L2C, UMR5221, F-34095 Montpellier, France. Additional authors for this research include B. Van Hattem, E. Uccelli, S. Conesa-Boj, P. Lefebvre, A.F.I. Morral and R.T. Phillips.
Keywords for this news article include: France, Europe, Montpellier, Engineering, Nanotechnology, Emerging Technologies
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC