title: Photoluminescence quantum efficiency of Er optical centers in GaN epilayers.
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 μm 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 μm.
authors.affiliation: Department of Physics &Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: V X
authors.initials: VX
authors.lastname: Ho
authors.affiliation: Department of Physics &Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Dao
authors.affiliation: Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409, USA.
authors.forename: H X
authors.initials: HX
authors.lastname: Jiang
authors.affiliation: Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409, USA.
authors.forename: J Y
authors.initials: JY
authors.lastname: Lin
authors.affiliation: Department of Electrical and Computer Engineering, New York University, Brooklyn, New York 11201, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Zavada
authors.affiliation: National High Magnetic Field Laboratory, 1800 E. Paul Dirac Dr., Tallahassee, Florida 32310, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: McGill
authors.affiliation: Department of Physics &Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: N Q
authors.initials: NQ
authors.lastname: Vinh