Résumé
In this work, strain relaxation in green-red emitting InGaN/GaN quantum well (QW) structures are investigated by transmission electron microscopy. In these structures, high indium content QW strain relaxation takes place through hexagonal domains formation inside GaN barrier just on QW top. With In increases, domains become limited by I1 stacking faults (SF) which can terminate by Frank partial dislocations at the junction when folding to prismatic planes. Closed domain defects two configurations are observed with rotated or parallel I1 basal SF. Two possible origins of a-type threading dislocations emanating from such defects and propagating to free surface, are then identified.