Nonradiative quenching of EPR signals in germanium-doped AlGaN: evidence for DX-center formation

2024/11/19 by Jason Forbus, Forbus, Jason, Darshana Wickramaratne +5
Engineering · Physics and Astronomy · #FOS: Physical sciences #GaN-based semiconductor devices and materials #Materials Science (cond-mat.mtrl-sci) #Organic Light-Emitting Diodes Research #Semiconductor materials and devices

paper · pdf · doi:10.48550/arxiv.2411.12896

openalex publication_date 2024/11/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

We present photo-electron paramagnetic resonance (EPR) measurements and first-principles calculations that indicate germanium (Ge) is a DX-center in AlGaN. Our photo-EPR measurements on Ge-doped AlGaN samples show no EPR spectra in the dark, while persistent EPR spectra is observed upon photoexcitation with photon energies greater than ~1.3 eV. Thermally annealing the samples decreased the EPR signal, with the critical temperature to quench the EPR signal being larger in the lower Al-content sample. Using detailed first-principles calculations of Ge in AlGaN, we show all of these observations can be explained by accounting for the DX configuration of Ge in AlGaN.

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