Comparison study of structural and optical properties of InxGa1-xN/GaN quantum wells with different in compositions

The effect of In on the structural and optical properties of InxGa1-xN/GaN multiple quantum wells (MQWs) was investigated. These were five-period MQWs grown on sapphire by metalorganic chemical vapor deposition. Increasing th e In composition caused broadening of the high-resolution x-ray diffraction superlattice satellite peak and the photoluminescence-excitation bandedge. This indicates that the higher In content degrades the interface quality b ecause of nonuniform In incorporation into the GaN layer. However, the samp les with higher In compositions have lower room temperature (RT) stimulated (SE) threshold densities and lower nonradiative recombination rates. The l ower RT SE threshold densities of the higher In samples show that the suppr ession of nonradiative recombination by In overcomes the drawback of greate r interface imperfection.