Carrier localization in basal-plane stacking faults in Si-doped nonpolar a-plane (1120) GaN epilayers containing different defect densities

Jihoon Kim, Sung Min Hwang, Yong Gon Seo, Jung Hoon Song, Ki Nam Park, Jung Ho Park, Soohwan Jang, Kwang Hyeon Baik

    Research output: Contribution to journalArticlepeer-review

    Abstract

    We investigated carrier localization in basal-plane stacking faults (BPSF) in Si-doped nonpolar a-plane GaN (a-GaN) epilayers containing various BPSF densities. Different SiNx interlayers were used to control the BPSF density in the a-GaN films. Significantly reduced BPSF densities were realized by the insertion of thick SiNx and multi-SiNx/GaN interlayers. BPSF-related emissions in low-temperature photoluminescence (PL) spectra showed the smallest full width at half maximum (25 meV), as well as predominant near-band-edge emission peaks for samples with multi-SiNx/GaN interlayers. The role of BPSFs as carrier/exciton localization centers was confirmed from the S-shaped temperature dependence of the BPSF peak energies. Moreover, carrier localization energies, extracted from the S-shaped curve fitted to Varshni's formula, were determined not to be solely dependent on BPSF density. It is suggested that localization energy can be influenced by other factors such as donors in the vicinity of a BPSF or polarization-induced electric fields. Carrier localization energies within BPSFs were in good agreement with the low-temperature activation energies from Arrhenius plots of integrated PL intensity. Stronger carrier localization within BPSFs can be realized when a-GaN epilayers contain multi-SiNx/GaN interlayers.

    Original languageEnglish
    Pages (from-to)11591-11598
    Number of pages8
    JournalJournal of Nanoscience and Nanotechnology
    Volume16
    Issue number11
    DOIs
    Publication statusPublished - 2016

    Bibliographical note

    Publisher Copyright:
    Copyright © 2016 American Scientific Publishers All rights reserved.

    Keywords

    • Basal-plane stacking fault
    • Carrier localization
    • GaN
    • Nonpolar

    ASJC Scopus subject areas

    • Bioengineering
    • General Chemistry
    • Biomedical Engineering
    • General Materials Science
    • Condensed Matter Physics

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