Effects of heavy Si doping on the structural and optical properties of n-GaN/AlN/Si(111) heterostructures
M. A. Zambrano-Serrano, Carlos A Hernández, O de Melo, M. Behar, S. Gallardo‐Hernández, Y.L. Casallas-Moreno, Arturo Ponce, Andrei Hernández‐Robles, D Bahena-Uribe, C. M. Yee‐Rendón, M. López‐López
Abstract
Abstract n-GaN/ AlN heterostructures were grown by molecular beam epitaxy on Si(111) substrates.The GaN films were n-type doped with silicon and the effect of doping concentration on the structural and optical properties was studied. Si doping promotes a reduction of dislocation density as revealed by x-ray data analysis and Transmission Electron Microscopy. Furthermore, a decrease in the yellow band measured by Photoluminescence Spectroscopy was observed when silicon doping concentration was increased up to 1.7 × 10 19 atoms cm −3 . A particular mosaic structure was induced by the Si-doping as inferred from Rutherford Backscattering measurements. The crystal quality shows a small degradation for very heavily doped samples (1.3 × 10 20 atoms cm −3 ).