Optical properties of Pr implanted GaN epilayers and AlxGa1-xN alloys

It has been shown recently that III-V nitrides serve as a good host for rar e earth elements and have many potential applications in optical communicat ions. Most work in rare earth implanted III-nitride materials so far has be en focused on GaN, while AlGaN alloys should have advantages over GaN due t o wider energy band gap. In this work, photoluminescence (PL) spectroscopy was used to investigate praseodymium (Pr) related transitions in Pr-implant ed GaN and AlxGa1-xN (0.15 < x < 0.33). The GaN epilayers and AlxGa1-xN all oys were rapid thermally annealed in nitrogen ambient to facilitate recover y from implantation related damage. We observed narrow PL emission bands ne ar 526, 650, 950, 1100 and 1300 nm. The dependence of PL emission including line width, peak position and emission intensity on sample temperature, ex citation intensity, aluminum concentration and annealing conditions were sy stematically studied. We found that PL intensity increases with annealing t ime and temperature. In contrast to GaN epilayers, different behaviors have been observed in the AlGaN host alloys. (C) 2001 Elsevier Science B.V. All rights reserved.