Hybrid nitride microcavity using crack-free highly reflective AlN/GaN and Ta2O5/SiO2 distributed Bragg mirrors

Abstract

We report the growth over 2 inch sapphire substrates of hybrid nitride-based microcavities using one crack-free highly reflective AIN/GaN distributed Bragg reflectors (DBRs) incorporated with AIN/GaN superlattice (SL) insertion layers and Ta2O5/SiO2 DBRs. The optical cavity is formed by a 5 lambda cavity consisting of n-type GaN, 10 pairs multiple quantum wells and p-type GaN sandwiched by AIN/GaN and Ta2O5/SiO2 DBRs. Reflectivity and photoluminescence measurements were carried out on these structures. A 29 periods AIN/GaN DBR incorporated with six AN/GaN superlattice insertion layers showed no observable cracks and achieved a peak reflectivity of 99.4% and a stopband of 21 run. Based on these high quality DBRs, the cavity mode is clearly resolved with a linewidth of 2.6 nm. These results demonstrate that the AIN/GaN system is very promising for the achievement of strong light-matter interaction and the fabrication of nitride-based vertical cavity surface emitting lasers. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.