A major obstacle in developing practical spin-based electronic devices is producing ferromagnetic semiconductors that exhibit a Curie temperature (Tc) higher than room temperature. Diluted magnetic semiconductors (DMSs), where a fraction of the host lattice cations are substitutionally replaced by 3d transition metal ions (TM@super 2+@), are promising candidates due to observation of high-Tc ferromagnetism in oxide DMSs. Recently, we have demonstrated a close link between the electronic structures and polarity-dependent high-Tc ferromagnetism of TM@super 2+@:ZnO DMSs.@footnote 1@ Our investigation, using complementary optical spectroscopic and photoelectrochemical probes, have identified light-induced donor- or acceptor-type ionizations states of the transition metal dopants immediately below the ZnO band edge in Co@super 2+@:ZnO and Mn@super 2+@:ZnO. These charge transfer electronic states clearly relate the observed high-Tc ferromagnetism in these materials to mediation by shallow donors or acceptors, as well as to the polarity of the mediating charge carrier. To further examine the interplay between the charge carriers and magnetic dopant ions we have successfully generated stable carriers in colloidal Co@super 2+@:ZnO and Mn@super 2+@:ZnO DMS quantum dots using photochemical methods.@footnote 2@ The carriers were identified as conduction band electrons and the resulting electron-magnetic dopant ion interactions were studied by electron paramagnetic resonance spectroscopy. This new motif of colloidal charged magnetic semiconductor nanocrystals provides new opportunities for examining spin effects in DMS nanostructures relevant to proposed spintronics technologies. @FootnoteText@ @footnote 1@K.R. Kittilstved, W.K. Liu, D.R. Gamelin, Nat. Mat. 5 (2006) 291.@footnote 2@W.K. Liu, K.R. Kittilstved, K.M. Whitaker, D.R. Gamelin, J. Am. Chem. Soc. 128 (2006) 3910.