Theoretical study and optimization of the green InGaN/GaN multiple quantum wells with pre-layer

Abstract The optical properties of green InGaN/GaN multiple quantum wells (MQWs) can be greatly affected by the large lattice mismatch between the GaN barrier and the InGaN quantum well due to the introduction of stress. To improve the quality of green MQWs, the insertion of a pre-layer before the MQWs is generally adopted. However, there does not exist a clear theoretical model by which to explain the effects of the pre-layer. In the present study, a lattice evolution model is proposed to describe the epitaxial growth process, by which the stress-blocking effect of the InGaN pre-layer is demonstrated. In addition, optimal designs for the active region of green MQWs with pre-layer are discussed. These results provide a theoretical basis for the preparation of high-quality green InGaN/GaN MQWs.