Structural and optical emission characteristics of InGaN thin layers and the implications for growing high-quality quantum wells by MOCVD

Defect formation and In segregation in InGaN/GaN quantum wells grown at various temperatures and with various well thicknesses were studied using cathodoluminescence, transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM). In 0.16 Ga 0.84 N quantum wells with In compositional nonuniformity and a small number of structural defects originating at the InGaN/GaN interface showed sharp and intense InGaN emission in cathodoluminescence (CL). Increasing the In composition caused surface roughness in the InGaN layer and the formation of stacking faults/dislocations originating at InGaN/GaN interface. This resulted in a reduction of the InGaN emission peak intensity. ( 1998 Elsevier Science B.V. All rights reserved. PACS: 61.16.Bg; 61.72.Ff; 61.72.Nn; 68.35.Ct; 68.35.Dv; 68.55.Jk; 68.55.Ln; 68.55.Nq; 78.60.Hk; 78.66.Fd; 81.05.Ea;