Disorder influenced optical properties of -sexithiophene single crystals and thin evaporated films

We report measurements on steady state and time resolved photoluminescence (PL) and PL- excitation (PLE) of sexithiophene single crystals and evaporated thin films. In contrast to the broad spectral features usually observed even in crystals, we have observed for the first time sharp emission peaks from the single crystal superimposed on a broader background. The broad background is due to emission from defect states, which are observable in PLE measurements and site-selective PL