Group V interdiffusion in In0.66Ga0.33As/ In 0.66Ga0.33As0.7P0.3 quantum well structures

The diffusion coefficient for arsenic and phosphorous interdiffusion has been measured as a function of temperature in In_0.66Ga_0.33As/ In_0.66Ga_0.33As_0.7P_0.3 strained quantum wells, using the photoluminescence from the n = 1 electron to heavy hole transition. The authors have used the shift in the photoluminescence from a 100Å single quantum well of In_0.66Ga_0.33As in In_0.66Ga_0.33 As_0.7P_0.3 barriers with annealing to monitor the interdiffusion. In this system there is no concentration gradient to drive group III interdiffusion and therefore the variation in the photoluminescence transition energy was modeled using only phosphorous/arsenic interdiffusion in the model. By performing several anneals to a single sample and measuring the shift in the photoluminescence after each anneal the interdiffusion was monitored as a function of time. Between temperatures of 900°C and 700°C the diffusion coefficient, D, can be described using the relationship D = D _oexp(-E_A/kT) where D_o = 507 cm² /s and E_A = 3.9 eV