Excimer Fluorescence of Poly( N -vinylcarbazole)

Fluorescence spectra and lifetimes of carbazole, 1,3-bis(N-carbazolyl)propane and poly(N-vinyl-carbazole) have been studied as a function of pressure to 30 kbar at room temperature and 77°K. Polymer films show exclusively excimer fluorescence (τ=43 nsec) at room temperature. This is not quenched at 77°K but appears together with a new emission (τ=12 nsec) attributed to traps arising from exciton coupling between adjacent carbazole chromophores. The comparative P, T response of the three compounds suggests that excimers do not form between adjacent chromophores in the amorphous polymer.