We report the quantum efficiency of photoluminescence processes of Er optical centers as well as the thermal quenching mechanism in GaN epilayers prepared by metal-organic chemical vapor deposition. High resolution infrared spectroscopy and temperature dependence measurements of photoluminescence intensity from Er ions in GaN under resonant excitation excitations were performed. Data provide a picture of the thermal quenching processes and activation energy levels. By comparing the photoluminescence from Er ions in the epilayer with a reference sample of Er-doped SiO2, we find that the fraction of Er ions that emits photon at 1.54 micron upon a resonant optical excitation is approximately 68%. This result presents a significant step in the realization of GaN:Er epilayers as an optical gain medium at 1.54 micron.
@article{arxiv.1611.08620,
title = {Photoluminescence quantum efficiency of Er optical centers in GaN epilayers},
author = {V. X. Ho and T. V. Dao and H. X. Jiang and J. Y. Lin and J. M. Zavada and S. A. McGill and N. Q. Vinh},
journal= {arXiv preprint arXiv:1611.08620},
year = {2016}
}