Spill coherence and formation dynamics of charged excitons in CdTe/CdMgZnTe quantum well

We report on a detailed study of the dynamics of charged and neutral excito ns in a p-doped CdTe/CdMgZnTe quantum well by time-resolved photoluminescen ce under strictly resonant excitation. The 1.5 ps resolution of the experim ental set-up allows us to resolve the rise time of the charged exciton phot oluminescence after resonant excitation of the neutral exciton. We measure tau(rise) approximate to 13 ps. A fit of the photoluminescence dynamics, wh ich takes into account the different relaxation mechanisms of the charged a nd neutral excitons, yields the charged exciton formation time. We find 65 ps. In a second part the spin coherence dynamics of the charged and neutral excitons in a transverse applied magnetic field is studied. We show that n either the spin orientation nor the spin coherence of electrons is destroye d by the formation process of charged excitons via exciton states.