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 similar to0.23 and similar to0.30 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. (C) 2001 American Institute of Physics.