Optical and microstructural studies of InGaNGaN single-quantum-well structures

D. M. Graham, A. Soltani-Vala, P. Dawson, M. J. Godfrey, T. M. Smeeton, J. S. Barnard, M. J. Kappers, C. J. Humphreys, E. J. Thrush

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We have studied the low-temperature (T=6 K) optical properties of a series of InGaNGaN single-quantum-well structures with varying indium fractions. With increasing indium fraction the peak emission moves to lower energy and the strength of the exciton-longitudinal-optical (LO)-phonon coupling increases. The Huang-Rhys factor extracted from the Fabry-Ṕrot interference-free photoluminescence spectra has been compared with the results of a model calculation, yielding a value of approximately 2 nm for the in-plane localization length scale of carriers. We have found reasonable agreement between this length scale and the in-plane extent of well-width fluctuations observed in scanning transmission electron microscopy high-angle annular dark-field images. High-resolution transmission electron microscopy images taken with a short exposure time and a low electron flux have not revealed any evidence of gross indium fluctuations within our InGaN quantum wells. These images could not, however, rule out the possible existence of small-scale indium fluctuations, of the order of a few at. %. © 2005 American Institute of Physics.
    Original languageEnglish
    Article number103508
    JournalJournal of Applied Physics
    Volume97
    Issue number10
    DOIs
    Publication statusPublished - 15 May 2005

    Keywords

    • LO phonon (coupling; optical and microstructural studies of InGaN/GaN single-quantum-well structures); Exciton (exciton recombination lifetime in InGaN/GaN single-quantum-well structures); Exciton luminescence (exciton-phonon; of InGaN/GaN single-quantum-well structures); Surface structure (of InGaN/GaN single-quantum-well structures); Microstructure; Quantum well devices (optical and microstructural studies of InGaN/GaN single-quantum-well structures)

    Fingerprint

    Dive into the research topics of 'Optical and microstructural studies of InGaNGaN single-quantum-well structures'. Together they form a unique fingerprint.

    Cite this