Photoluminescence quantum efficiency of Er optical centers in GaN epilayers

TL;DR

This study measures the quantum efficiency and thermal quenching mechanisms of Er optical centers in GaN epilayers, highlighting their potential for optical gain at 1.54 microns.

Contribution

It provides the first detailed analysis of photoluminescence quantum efficiency and thermal quenching in Er-doped GaN epilayers, advancing their application in optoelectronics.

Findings

Approximately 68% of Er ions emit photons at 1.54 microns under resonant excitation.

Thermal quenching mechanisms and activation energies were characterized.

GaN:Er epilayers show promise as optical gain media at 1.54 microns.

Abstract

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.