In this work, the influence of annealing process after GaN cap layer growth on the structural and optical properties of InGaN/InGaN muti-quantum wells has been investigated. It is found that the annealing has a positive effect on reducing the effect of the In rich layer on the subsequent growth of quantum barrier. At the same time, it is found that annealing can release stress and make the LLCs of QW more uniform, annealing will improve the interface between the quantum well and quantum barrier and reduce the influence of dislocation on the luminescence of MQW. However, a nonradiative recombination center with an activation energy around 110 meV was found to increase with annealing time.
