We report the growth and characterization of a Si-doped, n-type AlGaN layer with 45% Al composition. For the application of n-type AlGaN layers with high Al composition in ultraviolet emitters, we fabricated an n-Al_0.45Ga_0.55N layer with high crystalline quality and high electrical conductivity by inserting Al_0.85Ga_0.15N/AlN superlattices (SLs) to prevent cracks prior to growing the n-type AlGaN layer. The dislocation density in the n-AlGaN layer with 45% Al composition and SLs was less than 2.4 x 10¹⁰ cm^-2, which was lower than the dislocation density of 5.3 x 10¹⁰ cm^-2 for the n-AlGaN layer without SLs. The resistivity, mobility, and free electron concentration in the n-type Al_0.45Ga_0.55N layer with SLs were 2.2 x 10^-2 Ω×cm, 55.0 cm² /V-s, and 5.0 x 10¹⁸ cm^-3 at room temperature, respectively.

Date Published: 27 February 2014
PDF: 7 pages
Proc. SPIE 9003, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVIII, 90031S (27 February 2014); doi: 10.1117/12.2041398

Published in SPIE Proceedings Vol. 9003:
Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XVIII
Klaus P. Streubel; Heonsu Jeon; Li-Wei Tu; Martin Strassburg, Editor(s)