VIBRON-MEDIATED ELECTRONIC RELAXATION IN CRYSTALLINE CHLORINE

Luminescence decay of thin solid films of molecular chlorine exhibit d istinctly non-exponential temporal behavior following pulsed ultraviol et laser excitation. The temporal characteristics are dependent on sam ple temperature and laser fluence in the range 11-80 K. This behavior is attributed to internal conversion from the first excited A'((II2u)- I-3) electronic state to the ground state, which is accelerated by pho nons and localized vibrational excitons (vibrons). This unusual mechan ism of electronic relaxation is consistent with a recent theoretical m odel for the mechanism of explosive desorption of cryogenic films.