Investigation of temperature dependence of photoluminescence for fluorinated fullerene thin films

Temperature dependences of photoluminescence spectra of C60F18 and C60F24 thin films have been investigated in the range of T=15-300K. It was established that these spectra of C60F2x compounds strongly vary with temperature. The like behavior could be related to a phase transition of the ferro-electric type with TC∼150-200 K. The reflectivity of C60F18 measured at T=10-300K manifested a temperature change of peak positions and shape. These experiments support the idea of a phase transition at TC. The luminescence excitation spectra of C60F2x compounds demonstrate changes due to fluorination of the C60 skeleton.