Influence of strain relaxation on structural and optical properties of the InGaN/GaN multiple quantum wells with high In composition grown by metalorganic chemical vapor deposition was investigated. From photoluminescence and transmission electron microscopy it was found that, within the multiple quantum wells, the formation of misfit dislocation affects the degradation of optical properties more than the formation of stacking faults. For the multiple quantum wells with In composition above the critical In composition on the formation of misfit dislocation, the position of the main emission peak was significantly affected by the increase of quantum well numbers compared to samples with In composition below the critical In composition. The origins of redshift by the increase of quantum well numbers was believed to be caused by the increase of In segregation in the multiple quantum wells using high-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy.

Influence of Strain Relaxation on Structural and Optical Characteristics of InGaN/GaN Multiple Quantum Wells with High Indium Composition. H.K.Cho, J.Y.Lee, C.S.Kim, G.M.Yang: Journal of Applied Physics, 2002, 91[3], 1166-70