High Internal Quantum Efficiency Ultraviolet Emission from Phase-Transition Cubic GaN Integrated on Nanopatterned Si(100)

Richard Liu, Richard D Schaller, Chang Qiang Chen, Can Bayram

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Ultraviolet emission characteristics of cubic (c-) GaN enabled through hexagonal-to-cubic phase transition are reported. Substrate patterning and material growth are shown to affect phase purity and emission characteristics of c-GaN as studied by electron backscatter diffraction, and photo- and cathodoluminescence, respectively. Raman study shows a tensile strain in the c-GaN. Time-resolved photoluminescence reveals c-GaN band edge emission decay time of 11 ps. The ultraviolet emissions from both phases of GaN are linearly polarized in the same direction, which is along the 1120 and 110 directions of hexagonal GaN and c-GaN, respectively. Temperature-dependent (5.7 to 280 K) cathodoluminescence studies reveal an internal quantum efficiency of ∼29% at room temperature along with intrinsic and extrinsic defect energy levels of ∼124 and ∼344 meV, respectively, of the phase-transition c-GaN. Using the IQE value and carrier decay lifetime, a radiative lifetime of 38 ps is extracted. Overall, photonic properties of phase-transition c-GaN and their dependence on substrate patterning and material growth are reported.

Original languageEnglish
Pages (from-to)955-963
Number of pages9
JournalACS Photonics
Issue number3
Publication statusPublished - Mar 21 2018



  • cathodoluminescence
  • Cubic phase
  • electron backscatter diffraction
  • gallium nitride
  • photoluminescence
  • ultraviolet emitter

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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