The magnetic field effects on the carrier yield have been studied to clarify the spin dynamic process during photoinduced carrier generation in a fullerene (C-60)-doped poly(N-vinylcarbazole) (PVCz) film. The charge transfer (CT) complex of C-60 and the carbazole (Cz) chromophore is selectively excited. The total number of carriers that escaped from the geminate pairs decreases in the presence of magnetic fields, which arises from a hyperfine mechanism of the distant ion pairs involving C-60(-) and Cz(+). Time-resolved EPR measurements verify that the excited triplet state of C-60 is produced via its excited singlet state generated from the contact ion pair. The competitive formation processes of distant ion pairs and the excited states of C-60 from the contact ion pair are discussed. (c) 2005 Elsevier B.V. All rights reserved.