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arXiv · 1802.10222

Assignment of multiband luminescence due to the gallium vacancy-oxygen defect complex in GaN

Zijuan Xie·Yu Sui·John Buckeridge·Alexey A. Sokol·Thomas W. Keal·Aron Walsh
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Abstract

Oxygen is the most common unintentional impurity found in GaN. We study the interaction between substitutional oxygen (ON) and the gallium vacancy (VGa) to form a point defect complex in GaN. The formation energy of the gallium vacancy is largely reduced in n-type GaN by complexing with oxygen, while thermodynamic and optical transition levels remain within the band gap. We study the spectroscopy of this complex using a hybrid quantum-mechanical molecular-mechanical (QM/MM) embedded-crystal approach. We reveal how a single defect center can be responsible for multiband luminescence, including the ubiquitous yellow luminescence signature observed in n-type GaN, owing to the coexistence of diffuse (extended) and compact (localized) holes.

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Zijuan Xie, Yu Sui, John Buckeridge, Alexey A. Sokol, Thomas W. Keal, Aron Walsh. 2018-02-28. Assignment of multiband luminescence due to the gallium vacancy-oxygen defect complex in GaN. https://doi.org/10.1063/1.5026751

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