Roles of Al-vacancy complexes on the luminescence spectra of low dislocation density Si-doped AlN grown by halide vapor phase epitaxy

• DOI: 10.1063/5.0252149
• Publication Date: 2025-03-18T13:52:32Z
• Authors: S. F. Chichibu; K. Kikuchi; B. Moody; S. Mita; R. Collazo; Z. Sitar; Y. Kumagai; S. Ishibashi; A. Uedono; K. Shima
• Keywords: Wide-bandgap semiconductor; Vapor phase

Roles of Al-vacancy (VAl) complexes on the cathodoluminescence (CL) spectra Si-doped AlN grown by halide vapor phase epitaxy (HVPE) a physical-vapor-transported (0001) substrate are described, making connection with results positron annihilation measurements. A combination HVPE and enabled decreasing deleterious carbon concentration dislocation density, respectively, thus accentuating influences VAl-complexes luminescence processes. low-temperature CL spectrum unintentionally doped exhibited predominant excitonic emissions at around 6 eV marginal deep-state emission band 3.7 that originates from residual (<1016 cm−3) nitrogen sites (CN). However, sample was revealed to contain considerable amount (∼1017 vacancy clusters, most likely comprising VAl nitrogen-vacancies (VN), namely, VAlVN1−2, which act as nonradiative recombination centers decrease overall intensity elevated temperatures. With increasing Si-doping ([Si]), major species progressively changed VAlVN1−2 VAlON1−2, where ON is oxygen N sites, exhibit other bands ranging 3.2 3.5 eV. Further increase in [Si] gave rise formation donor-compensating defects Si second-nearest-neighbor Al (SiAl), abbreviated VAl−SiAln, shoulders 2.9–3.0 When exceeded 5 × 1018 cm−3, an 4.5 emerged, had been ascribed originate nearest-neighbor SiAlCN complexes. Because VAl-complexes, including those containing impurities, thermally stable, incorporation vacancies should be blocked growth stage.