Abstract

Polydiacetylenes (PDAs) are a well-known class of one-dimensional π-conjugated semiconducting polymers. They display optical transitions with high oscillator strength and low photoluminescence efficiency (typically 10^-4) This is consistent with ultrafast relaxation of the primary photoexcited state 1¹B_u into one or more dark states, i.e. states which are energetically below the 1¹B_u state and not optically coupled to the ground state [1]. The recent availability of sub-10-fs pulses in the visible range enables direct monitoring of this process.

© 2000 IEEE