Charge transfer complexes (CTCs) exhibit excellent initiating abilities as safe photo, thermal, or photo/thermal dual initiators, which cannot be achieved by classical initiators. New dual initiators based on a phenacyl sulfonium salt (ITXPhenS) acceptor and selected donors capable of initiating both thermal and photochemical polymerizations are investigated. Excellent dual initiating ability and long storage stability were examined by RT-FTIR and DSC experiments. The formations of the CTCs were confirmed by UV-vis spectroscopic investigations and MOC (Molecular Orbital Calculations). The application of the newly developed initiating system in laser writing experiments at 405 nm shows excellent spatial resolution performance. High-tech composites with tack free surfaces can be easily fabricated by employing these kinds of CTCs via fast photochemical curing of the surface associated with a thermal curing in depth. Both carbon fibers and glass fiber composites were prepared.