Ga- and N-polar GaN Growths on SiC Substrate
Technical Report,30 Sep 2014,29 Sep 2017
National Taiwan University Taipei Taiwan
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The growth of a two-section, core-shell, InGaNGaN quantum-well QW nanorod- NR- array light-emitting diode device based on a pulsed growth technique with metalorganic chemical vapor deposition MOCVD is demonstrated. A two-section n-GaN NR is grown through a tapering process for forming two uniform NR sections of different cross-sectional sizes. The cathodoluminescence CL, photoluminescence PL, and electroluminescence EL characterization results of the two-section NR structure are compared with those of a single-section NR sample, which is prepared under the similar condition to that for the first uniform NR section of the two-section sample. All the CL, PL, and EL spectra of the two-section sample peaked between 520 and 525 nm are red-shifted from those of the single-section sample peaked around 490 nm by 30 nm in wavelength. Also, the emitted spectral widths of the two-section sample become significantly larger than their counterparts of the single-section sample. The PL spectral full-width at half-maximum increases from 37 to 61 nm. Such variations are attributed to the higher indium incorporation in the sidewall QWs of the two-section sample due to the stronger strain relaxation in an NR section of a smaller cross-sectional size and the more constituent atom supply from the larger gap volume between neighboring NRs.
- Physical Chemistry