Interdiffusion of In and Ga in InGaN/GaN multiple quantum wells

Thermal stability of InxGa1-xN/GaN multiple quantum wells with InN mole fraction of ∼0.23 and ∼0.30 was investigated by postgrowth thermal annealing. Low temperature photoluminescence spectroscopy was employed to determine the temperature dependence of the interdiffusion coefficient of In and Ga in InGaN/GaN quantum wells. The interdiffusion process is characterized by a single activation energy of about 3.4±0.5 eV and governed by vacancy-controlled second-nearest-neighbor hopping. Due to composition inhomogeneity, lower diffusivity is observed at the early stage of thermal annealing.