2015/07/17 by Deepu George, George, D. K., Matthew Hawkins +11
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Ga2O3 and related materials #GaN-based semiconductor devices and materials #Materials Science (cond-mat.mtrl-sci) #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.1507.05119
openalex publication_date 2015/07/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report direct evidence of two mechanisms responsible for the excitation of optically active Er3+ ions in GaN epilayers grown by metal-organic chemical vapor deposition. These mechanisms, resonant excitation via the higher-lying inner 4f shell transitions and band-to-band excitation of the semiconductor host, lead to narrow emission lines from isolated and the defect-related Er centers. However, these centers have different photoluminescence spectra, decay dynamics, and excitation cross sections. The isolated Er optical center, which can be excited by either mechanism, has the same decay dynamics, but possesses a much higher cross-section under band-to-band excitation. In contrast, the defect-related Er center can only be excited through band-to-band excitation but has the largest cross-section. These results explain the difficulty in achieving gain in Er doped GaN and indicate new approaches for realization of optical amplification, and possibly lasing, at room temperature.