Reduction in the concentration of cation vacancies by proper Si-doping in the well layers of high AlN mole fraction AlxGa1–xN multiple quantum wells grown by metalorganic vapor phase epitaxy

• Published in: Applied physics letters Vol. 107; no. 12
• Main Authors: Chichibu, S F, Miyake, H, Ishikawa, Y, Furusawa, K, Hiramatsu, K
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 21-09-2015
• Subjects: Ammonia; Applied physics; Cathodoluminescence; Cations; Decomposition reactions; Doping; Epitaxial growth; Luminescence; Metalorganic chemical vapor deposition; Quantum wells; Silicon; Vacancies
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4931754

Appropriate-amount Si-doping in the well layers significantly improved the luminescence efficiency of Al0.68Ga0.32N/Al0.77Ga0.23N multiple quantum wells. To understand the mechanisms, spatio-time-resolved cathodoluminescence measurements and self-consistent Schrödinger-Poisson calculations were carried out. The increase in the luminescence lifetime at room temperature, which reflects the decrease in the concentration of nonradiative recombination centers (NRCs), was correlated with increased terrace width of Si-doped wells. The results suggest the importance of H3SiNH2 doping-reactant formation that gives rise to enhanced decomposition of NH3 and provides wetting conditions by surface Si-N bonds, which reduce the total energy and concentration of NRCs composed of cation vacancies.