Concentration dependent interdiffusion in InGaAs/GaAs as evidenced by high resolution x-ray diffraction and photoluminescence spectroscopy

A high resolution x-ray diffraction (HRXRD) and photoluminescence study of a 10 nm InGaAs/GaAs quantum well structure repeatedly diffused under thermally accurate and timed annealing conditions demonstrates that the Fickian model with a constant coefficient of diffusion is inadequate and that the distribution of compositions of the diffused well cannot be fitted with error functions. A simple model, with the well retaining its square shape and homogeneity while dissolving the barriers when annealed, is successful in modelling both the HRXRD and photoluminescence data. (C) 2005 American Institute of Physics.