Dose dependence of the charge carrier mobility and decay kinetics in radiation polymerized diacetylenes

Single crystals of the diacetylene derivatives ETCD, 4BCMU, IPUDO, and DCH were polymerized by repeated irradiation with single pulses of 3 MeV electr ons. The conductivity induced by these pulses was determined as a function of the accumulated dose. At low doses the transient radiation-induced condu ctivity increases due to the production of polymer chains, on which the cha rge carriers are highly mobile. For low accumulated radiation dose the char ge carrier mobility is found to be of the order of 1 cm(2)/(V s). For highe r accumulated dose the lifetime of the charge carriers toward trapping as w ell as their mobility decrease. For accumulated radiation doses that are co nventionally used to produce polydiacetylenes, the charge carrier mobility has decreased by approximately 1 order of magnitude.