Limiting switching characteristics of VDF/TrFE copolymer thin films

The copolymer of vinylidene fluoride (VDF) with trifluoroethylene (TrFE) is a ferroelectric polymer undergoing polarization reversal as a result of rotational motions of molecules about their chain axes. It requires a very high electric field of approximately 100 MV/m for polarization reversal. Therefore, the thickness reduction below 50 nm is a technological requirement to achieve low-voltage operations in ferroelectric polymer applications. The authors reported that thickness reduction caused no effect on the switching characteristics down to at least 50 nm, when Au instead of Al was used for the electrodes [1]. In this work, we conduct electric measurement on 14~330-nm-thick films and shall discuss the structural and electrical limit of the ferroelectric switching in VDF/TrFF copolymer films.