X-ray Diffraction Study of InGaN/GaN Superlattice Implanted With Eu 3+ Ions
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1202-I05-20
X-ray Diffraction Study of InGaN/GaN Superlattice Implanted With Eu3+ Ions Mohammad A. Ebdah1, Martin E. Kordesch1, Andre Anders2, and Wojciech M. Jadwisienczak3. 1 Department of Physics and Astronomy, Ohio University, Athens, OH 45701, U.S.A. 2 Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S.A. 3 School of EECS, Ohio University, Athens OH, 45701, U.S.A. ABSTRACT In this work, europium implanted InxGa1-xN/GaN SL with a fixed well/barrier thickness ratio grown by metal-organic chemical-vapor deposition (MOCVD) on GaN/(0001) sapphire substrate were investigated. The as-grown and Eu3+ ion implanted InxGa1-xN/GaN SLs were annealed at different temperatures ranging from 600°C to 950°C in nitrogen ambient. The quality of the SL interfaces in undoped and implanted structures has been investigated by X-ray diffraction (XRD) at room temperature. The characteristic satellite peaks of SLs were measured for the (0002) reflection up to the second order in the symmetric Bragg geometry. The XRD simulation spectrum of the as-grown SL agrees well with the experimental results. The simulation results show 6 at.% of Indium in the InxGa1-xN well sub-layers, with thicknesses of 2.4 and 3.3 nm for single InxGa1-xN well and GaN barrier, respectively. It was observed that annealing the undoped SL does not significantly affect the interfacial quality of the superstructure, whereas, the Eu3+ ion implanted InxGa1-xN/GaN SL undergo partial induced degradation. Annealing the implanted SLs shows a gradual improvement of the multilayer periodicity and a reduction of the induced degradation with increasing the annealing temperature as indicated by the XRD spectra. INTRODUCTION Growth, structural, and optical characterization of rare earth (RE) ion doped low dimensional III-nitride (III-N) structures such as multiple quantum wells (QWs) and superlattice (SLs) have received recently increasing interest due to the technological applications of such nanostructures [1-4]. InGaN films have been extensively grown by organometallic vapor phase epitaxy (OMVPE) [5-7], molecular beam epitaxy (MBE) [8], metal organic chemical vapor deposition (MOCVD) [9], and radio frequency (RF) magnetron sputtering [10]. In these films, the indium content influences the structural as well as the optical properties of InGaN sub-layers. With the bandgap of end members (Eg(InN) = 0.8 eV, and Eg(GaN) = 3.4 eV), the band edge of the InGaN alloy can be engineered by varying the indium at.% (x parameter) in the InxGa1-xN alloy to covers a broad spectral range. Accordingly, the structural design of InxGa1-xN/GaN SL structures is directly related to the desired optical properties. The strain, critical thickness, and phase separation are important factors in stabilizing InGaN on GaN sub-layers. Furthermore, the progress in III-N materials growth creates an opportunity to investigate the sensitization of the RE ions emission when doped into low dimensional quantum structures such as SLs. The most challenging obstacle on the path to achieving the full potent
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