Rare Earth Doped Semiconductors for Phosphors and Lasers

摘要

The emission properties of rare earth (RE) doped III-nitrides remain of significant current interest for applications in display technology, optical communications, and solid-state lasers. Full-color displays based on RE doped GaN/AlGaN films have been developed by collaborators at the University of Cincinnati (Prof. A. Steckl group). In addition, the first demonstration of laser activity from GaN:Eu was recently reported indicating the potential of this novel class of materials as solid-state gain media. In this final report, laser spectroscopic studies of the visible and infrared emission properties of GaN:Eu, GaN:Er, and AlGaN:Tm thin-films are presented. Collaborators at the University of Cincinnati prepared the investigated samples using solid-source MBE. Time-resolved and steady state photoluminescence studies were performed on RE doped GaN/AlGaN films in order to gain a better understanding on the RE incorporation, excitation mechanisms, and emission efficiency. The RE emission properties were investigated as a function of excitation wavelength, temperature, host composition (e.g. Tm:AlGaN), growth conditions (e.g. Ga-flux dependence of Er:GaN), and growth method (e.g. IGE growth of Eu:GaN). Initial studies of Er-doped III-Nitride double heterostructures grown at Kansas State University are also summarized.