Nonpolar p-contact layer based on AlGaN/GaN distributed Bragg reflector

The nonpolar a-plane Mg-doped p-type AlGaN/GaN distributed Bragg reflectors (DBRs) were grown for the first time with metal organic chemical vapor deposition technology. The structural, optical, and electrical properties of the nonpolar p-DBRs were characterized with various kinds of technical tools. The measurement results demonstrate that a stopband centered at 390 nm with a peak reflectivity of 55% was achieved. Meanwhile, a relatively high reflectivity (>35%) could also be obtained within the wavelength range of 270-320 nm for the nonpolar p-DBR which was intended to be a reflector with a working wavelength at 280 nm. Additionally, a hole concentration higher than 2 × 1017 cm−3 was obtained with the nonpolar p-DBRs.