The effect of X-ray irradiation on poly(p-phenylene vinylene) and derivatives

We have studied the effect of X-ray exposure on poly(p-phenylene vinylene), PPV, and an iodo- derivative of PPV, poly(2-iodo-1,4-phenylene vinylene), PIPV. We report the effect of the chemical changes produced on the optical absorption (bleaching), photoluminescence (quenching), electrical conductivity (enhancement), and field-effect mobility (enhancement). We attribute these changes in part to p-type doping of these polymers caused by the radiation exposure. These effects are enhanced for the iodo-PPV which has an increased X-ray absorption cross section and the possibility of iodine doping after C-I bond scission.