Low-temperature luminescence of thin C 60 films of different structures

We present the results of investigation of low-temperature (5 K) photoluminescence of thin fullerite C 60 films of various structures obtained on monocrystalline NaCl substrates by vacuum deposition at temperatures in the interval 290–400 K. Depending on the conditions of deposition, the film structure, which was controlled by the standard transmission high-energy electron diffraction (THEED) technique, varies from a disoriented structure to an oriented structure with different average sizes of microcrystals. The effect of the film structure on the photoluminescence spectral band of fullerite, associated with the luminescence of structural defects (X -traps), is attributed to the peculiarities of transport and capture of coherent singlet excitons in single crystals of various sizes.