Optical Characterization of Rare Earth-doped Wide Band Gap Semiconductors
Abstract
Comprehensive spectroscopic studies of Er implanted GaN and in-situ Er doped AlN and GaN prepared by metalorganic molecular beam epitaxy were carried out. Each investigated sample exhibited strong 1.54 um luminescence at room temperature. it was found, however, that the incorporation and excitation schemes of Er in III Nitrides are rather complex and strongly depend on the material synthesis. For example, it was observed that high oxygen and carbon concentrations in GaN:Er greatly enhance the 1.54 um Er(3+) PL intensity under below gap excitation. Photoluminescence excitation (PLE) studies revealed that oxygen/carbon introduces a broad below gap PLE band, which provides an efficient pathway for E(3+) excitation. Under above gap excitation, however, the absolute Er(3+) PL intensity from GaN:Er samples was greatly reduced and only a weak PL dependence on the oxygen and carbon concentration was observed. Pump intensity dependent E(3+) PL studies revealed that the Er(3+) excitation efficiency for above gap pumping is reduced by a factor of 30 compared to below gap pumping. Based on the efficient below gap Er excitation a novel hybrid InGaN/GaN:Er LED operating at 1.54 um was demonstrated. Questions concerning the overall efficiency of this novel hybrid LED need to be further addressed in the future. More materials engineering focusing on improvement in the Er excitation efficiency is necessary to optimize the 1.54 um E(3+) PL from GaN:Er for practical device applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 06, 1999
- Accession Number
- ADA369833
Entities
People
- Uwe Hömmerich
Organizations
- Hampton University