Partial strain relaxation by stacking fault generation in InGaN multiple quantum wells grown on ( 1 1 ¯ 01 ) semipolar GaN

We have investigated the structural properties and relaxation phenomenon of InGaN multiple quantum wells (QWs) on ( 1 1 ¯ 01 ) semipolar GaN templates grown on patterned (001) silicon substrates by selective area growth technique. Our studies by transmission electron microscopy and x-ray diffraction reciprocal space mapping reveal that QWs emitting light at 540 nm experience significant strain relaxation along the in-plane [ 1 1 ¯ 0 2 ¯ ] direction by the generation of an array of basal stacking faults (BSF). The generation of BSFs in 540 nm QWs could be an important factor limiting its luminescence efficiency.