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

Thermal stability of InxGa1-xN/GaN multiple quantum wells with InN mole fra ction of similar to0.23 and similar to0.30 was investigated by postgrowth t hermal annealing. Low temperature photoluminescence spectroscopy was employ ed to determine the temperature dependence of the interdiffusion coefficien t of In and Ga in InGaN/GaN quantum wells. The interdiffusion process is ch aracterized by a single activation energy of about 3.4 +/-0.5 eV and govern ed by vacancy-controlled second-nearest-neighbor hopping. Due to compositio n inhomogeneity, lower diffusivity is observed at the early stage of therma l annealing. (C) 2001 American Institute of Physics.