OPTICAL STUDY OF INTERMIXING IN CDTE CDMGTE QUANTUM-WELLS/

CdTe/CdMgTe quantum wells were processed by rapid thermal annealing (R TA) at temperatures between 390-degrees-C and 550-degrees-C. Due to th e interdiffusion of Cd and Mg ions the photoluminescence of the quantu m wells exhibits strong blue shifts up to 360 meV at the highest annea ling temperature. This energy shift is close to the total discontinuit y of the quantum well structures, indicating an almost perfect interdi ffusion of barrier and well material. By using a simple model for the quantum well potential changes due to interdiffusion we derive the int erdiffusion length as a function of the annealing temperature. The int erdiffusion is characterized by an activation energy of 2.8 eV.