The interdiffusion behavior of In1-xGaxAs1-yPy/In1-x'Gax'As1-y'Py' multiple quantum-well heterostructures, with various built-in strains and layer thicknesses, was investigated by monitoring their photoluminescence. All of the samples which were annealed at 850C consistently exhibited a blue-shift of the heavy hole exciton line as a result of interdiffusion across the hetero-interfaces. Data on a nearly strain-compensated structure, with a constant P/As ratio and In-rich wells, showed that the blue-shift of the excitonic line was the result of group-III atom interdiffusion alone, as in the GaAs/GaAlAs system. The In-Ga interdiffusion could be described by a coefficient of about 4.72 x 10-16cm2/s. In the case of lattice-matched and compressively strained structures, simultaneous interdiffusion on the group-III and group-V sub-lattices yielded an effective interdiffusion coefficient which ranged from 3.83 x 10-16 to 5.51 x 10-16cm2/s.

A.Hamoudi, A.Ougazzaden, P.Krauz, K.Rao, M.Juhel, H.Thibierge: Japanese Journal of Applied Physics, 1995, 34[1-1], 36-41