Thermally-induced interdiffusion in quantum wells was investigated by using photoluminescence techniques. The single quantum-well structures were grown by means of molecular beam epitaxy, and were subjected to rapid thermal annealing (60s, 380 to 520C). A blue shift close to the barrier energy was observed which reflected the occurrence of almost perfect interdiffusion between the well and the barrier material. An activation energy of 2.8eV (with a pre-exponential factor of 37000cm2/s) was deduced for the interdiffusion process (figure 18).

D.Tönnies, G.Bacher, A.Forchel, A.Waag, G.Landwehr: Applied Physics Letters, 1994, 64[6], 766-8

Figure 18

Interdiffusion of CdTe/(Cd,Mn)Te Quantum Wells

Squares: 10nm CdTe/Cd0.88Mn0.12Te, circles: 4nm CdTe/Cd0.86Mn0.14Te