Improved performance of semi-polar (11-22) GaN-based light-emitting diodes grown on SiNx interlayer

We report on the effectiveness of the in-situ SiNx nanomask in reducing defects in semipolar (11-22) GaN films grown on m-plane sapphire. The properties of the semipolar InGaN/GaN double quantum well (DQW) LEDs were improved with a high-quality (11-22) GaN epilayer grown on the SiNx interlayer. High resolution X-ray diffraction analysis revealed that there was a great reduction in the full width at half maximum of both on-axis and off-axis planes on SiNx interlayer. The room temperature cathodoluminescence (CL) band-edge emission intensity of (11-22) GaN grown on the SiNx interlayer was approximately 4 times higher than that of GaN without the SiNx interlayer, which suggests reduction in the nonradiative recombination centers. The optical power of LEDs with the SiNx interlayer was 200% and 270% higher at injection currents of 20 mA and 100 mA, respectively, compared to the reference LEDs.

► The effect of semipolar (11-22) GaN LEDs grown on a SiNx interlayer was investigated. ► The SiNx interlayer has efficiently reduced the defects of semipolar (11-22) GaN. ► The optical power of LEDs with the SiNx interlayer was higher compared to the reference.