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Title: Effects of ternary mixed crystal and size on optical phonons in wurtzite nitride core-shell nanowires

Within the framework of dielectric continuum and Loudon's uniaxial crystal models, existence conditions dependent on components and frequencies for optical phonons in wurtzite nitride core-shell nanowires (CSNWs) are discussed to obtain dispersion relations and electrostatic potentials of optical phonons in In{sub x}Ga{sub 1−x}N/GaN CSNWs. The results show that there may be four types of optical phonons in In{sub x}Ga{sub 1−x}N/GaN CSNWs for a given ternary mixed crystal (TMC) component due to the phonon dispersion anisotropy. This property is analogous to wurtzite planar heterojunctions. Among the optical phonons, there are two types of quasi-confined optical (QCO) phonons (named, respectively, as QCO-A and QCO-B), one type of interface (IF) phonons and propagating (PR) phonons existing in certain component and frequency domains while the dispersion relations and electrostatic potentials of same type of optical phonons vary with components. Furthermore, the size effect on optical phonons in CSNWs is also discussed. The dispersion relations of IF and QCO-A are independent of the boundary location of CSNWs. Meanwhile, dispersion relations and electrostatic potentials of QCO-B and PR phonons vary obviously with size, especially, when the ratio of a core radius to a shell radius is small, and dispersion relation curves of PR phonons appear tomore » be close to each other, whereas, this phenomenon disappears when the ratio becomes large. Based on our conclusions, one can further discuss photoelectric properties in nitride CSNWs consisting of TMCs associated with optical phonons.« less
Authors:
; ; ; ;  [1]
  1. School of Physical Science and Technology, Inner Mongolia University, Hohhot 010021 (China)
Publication Date:
OSTI Identifier:
22273572
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ANISOTROPY; CRYSTAL MODELS; CRYSTALS; DIELECTRIC MATERIALS; DISPERSION RELATIONS; GALLIUM NITRIDES; HETEROJUNCTIONS; INTERFACES; PHONONS; POTENTIALS; QUANTUM WIRES