Influence of an electric field on photodegradation and self-healing in disperse orange 11 dye-doped PMMA thin films

The influence of an applied electric field on reversible photodegradation of disperse orange 11 doped into (poly)methyl-methacrylate (PMMA) is measured using digital imaging and conductivity measurements. Correlations between optical imaging, which measures photodegradation and recovery, and photoconductivity enables an association to be made between the damaged fragments and their contribution to current, thus establishing that damaged fragments are charged species, or polarizable. Hence, the decay and recovery process should be controllable with the applications of an electric field. Indeed, we find that the dye polymer system is highly sensitive to an applied electric field, which drastically affects the decay and recovery dynamics. We demonstrate accelerated recovery when one field polarity is applied during burning and the opposite polarity is applied during recovery. This work suggests that the damage threshold can be increased through electric field conditioning, and the results are qualitatively consistent with the domain model of Ramini. The observed behavior will provide useful input into better understanding the nature of the domains in the domain model, making it possible to design more robust materials using common polymers and molecular dopants.