Growth and characterization of nitride-based distributed Bragg reflectors

• Published in: Physica Status Solidi (b) Vol. 248; no. 8; pp. 1748 - 1755
• Main Authors: Kruse, Carsten, Dartsch, Heiko, Aschenbrenner, Timo, Figge, Stephan, Hommel, Detlef
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-08-2011; WILEY‐VCH Verlag
• Subjects: AlGaN; AlInN; Bragg reflectors; Gallium nitrides; MBE; MOVPE; nitrides; Optoelectronics; Reflectivity; Spectra; Tradeoffs; Wavelengths
• ISSN: 0370-1972; 1521-3951; 1521-3951
• DOI: 10.1002/pssb.201147174

We report on a systematic study concerning the realization of nitride‐based distributed Bragg reflectors (DBRs) for opto‐electronic applications in the near‐UV to visible spectral range. Different material combinations are used in order to find an optimized trade‐off concerning peak reflectivity, stop band width, and strain state of the Bragg mirrors. For the high refractive index material GaN is used in all cases, while for the low index material a layer of either AlGaN or AlInN, respectively, or a AlN/(In)GaN short‐period superlattice (SL) is employed. The best peak reflectivity of 97% at a wavelength of 495 nm is achieved for a lattice matched Bragg reflector based on the GaN/AlInN material combination.
Transmission electron microscopy image of a 30‐fold distributed Bragg reflector consisting of AlInN (dark) and GaN (bright) layers.