Ultrafast optical dynamics of epitaxially grown polycarbazolyldiacetylene films

The ultrafast dynamics of poly[1.6‐di(n‐carbazolyl‐2.4hexadiyne] (pDCH) has been investigated with femtosecond optical pulses. A transient configuration change of the pDCH backbone occurs in the first 50 fs leading to a butatrienic‐like structure in the excited state. This process is followed by a thermalization of free excitons in the coordinate space with a time constant ∼150 fs.