Hyper-Rayleigh scattering as a screening tool for the optimization of piezoelectric polymers

The use of piezoelectric polymers has been proposed and investigated in different Space-related environments, for example, as ultra-light mirrors in space telescopes or as piezoelectric actuators. Even though some piezoelectric polymers have been shown to be as efficient as the more traditional piezoelectric crystals, no systematic exploration of the different molecular motives available for piezoelectricity has been performed, partly due to experimentally challenging conditions: new structures must be generated in enough quantity to be able to produce thin films, and with measurable piezoelectric response. Consequently, few structure-property relationships have been derived for the piezoelectric performance of polymer based materials. We show how, under certain conditions, the characterization of the second-order nonlinear molecular response through the Hyper-Rayleigh scattering technique, can be used as a screening technique for the optimization of the piezoelectric response of poled-doped materials. In contrast to the piezoelectric characterization, a Hyper-Rayleigh experiment can be performed with minimal amounts of chromophores (~mg) in solution, and is relatively quick. Therefore, we propose to use the Hyper-Rayleigh scattering technique as a screening tool for the search of optimized piezoelectric polymers.