Picosecond transient grating studies of carrier diffusion in diluted magnetic semiconductor superlattices

Abstract

(111)-oriented Cd1-x Mnx Te superlattice films grown on (100)-oriented GaAs by molecular beam epitaxy were characterized by X-ray diffraction, low-temperature photoluminescence, and optical reflectivity. A picosecond time-resolved transient grating technique was used to generate and monitor the carrier dynamics. Measurements were performed as a function of the carrier energy, density, and sample temperature. In particular, the temperature dependence of the carrier scattering time as the system is both warmed and cooled through the spin-glass transition was studied.