| 研究実績の概要 |
Zn doped GaN samples were successfully fabricated with a low dopant density using Metal Organic Chemical Vapour Deposition, and probed with micro photoluminescence spectroscopy. Previously unreported, spatially localized emission lines were detected and investigated. The emission lines are in the blue region of the spectrum with energies between ~2.6eV to ~2.75eV. The emission lines have linewidths in the region of a few meV, and emit after excitation above the GaN bandgap (with excitation energy above ~3.5eV). Unfortunately, single photon emission could not be measured, so further optical characterization was performed to ascertain additional information on these novel emission centers. In the final year of the project, metal masks with apertures where fabricated in an attempt to reduce the emission background present in the samples emission spectrum due to other Zn related emission states. However, even when using these masks, it was not possible to isolate single photon emission from an individual emitter. Temperature studies on the emission were also performed, revealing a significant phonon related broadening and a rapid quenching of the emission intensity as temperature is raised above 10K, indicating that non-radiative recombination is dominant even at low temperatures.
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