Manganese-diffusion-induced n-doping in semiconductor structures   containing Ga(Mn)As layers
  Semiconductor structures using ferromagnetic semiconductors as spin injectors are promising systems for future spintronic devices. Here, we present combined photoluminescence (PL) and time-resolved magneto-optical experiments of a nominally nonmagnetic quantum well(QW) separated by a thin barrier from a ferromagnetic Ga(Mn)As layer. Due to the partial quenching of the PL, we conclude that there is a significant Mn backdiffusion into the QW. Moreover, from the time-resolved measurements, we infer that the Mn leads to n-type doping within the QW, and, in addition, strongly increases the electron spin dephasing time. 
T. Korn, R. Schulz, S. Fehringer, U. Wurstbauer, D. Schuh, W.   Wegscheider, M. W. Wu, and C. Sch\"uller