In search for efficient near infra-red systems exhibiting broadband significant persistent spectral hole-burning properties for coherent femtosecond pulse-shaping purposes, we have recently demonstrated the potentiality of C 7 0 fullerene to act as an optical enhancer of the hole-burning properties of Si-naphthalocyanine (SiNPc)-doped PVB films in two-colour hole-burning experiments. We hereby report on an increase of the one-colour hole-burning efficiency of SiNPc when C 7 0 is present. We present some spectroscopic evidence that the energy initially absorbed by SiNPc molecules excited at 792nm is transferred to C 7 0 fullerene molecules, allowing them to play a role as hole-burning activators.