We have studied the effect of X-ray exposure on poly(p-phenylene vinyl
ene), PPV, and an iodo- derivative of PPV, poly(2-iodo-1,4-phenylene v
inylene), PIPV. We report the effect of the chemical changes produced
on the optical absorption (bleaching), photoluminescence (quenching),
electrical conductivity (enhancement), and field-effect mobility (enha
ncement). 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 sectio
n and the possibility of iodine doping after C-I bond scission.