Structural impact on piezoelectricity in PVDF and P(VDF-TrFE) thin films

PVDF and its mostly used copolymer P(VDF-TrFE) are known to possess piezoelectric properties which strongly vary with processing conditions. As the final target of processing ultimately is the structure of the polymer, establishing a more detailed link between structure and properties would ease both the understanding and the practical usage of films piezoelectric activity. In spite of a number of thorough studies exploiting the nature of piezoelectricity in PVDF, available data does not generally exhibit reliable level of consistency and, in some cases, elements of contradiction are observed. Making no claim to be exhaustive in this vast area, we present a survey and discuss on a number of results both available and obtained by ourselves in an effort to assist to better interpretation and further progress in the field.