화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.154, No.10, G224-G228, 2007
Enhanced functional and structural characteristics of poly(vinylidene-trifluoroethylene) copolymer thin films by corona poling
Electrical poling is of much interest for the enhancement of polarization properties of ferroelectric materials such as poly(vinylidene- trifluoroethylene) [P( VDF- TrFE )] in applications ranging from memory devices to piezoelectric actuation. Here, we report the changes in dielectric and optical properties correlated with structural modification of P(VDF- TrFE ) thin films (< 1 mu m thickness) subjected to corona poling at low voltages (6 kV ) under various thermal conditions. Enhanced crystallinity of hot- poled samples was observed independent of thermal history and crystalline structure, indicating the absence of recrystallization during poling. Absorption measurements confirmed the ordered structure in hot- poled samples due to the permanent orientation of the dipoles and higher crystallinity, thus resulting in increased and long-retained capacitance of the ferroelectric P(VDF-TrFE) capacitor device from high frequency C-V characterization. X-ray photoelectron spectroscopy further confirmed the shifting of C and F core orbitals to higher binding energy is related to formation of more ferroelectric phases by corona poling. (c) 2007 The Electrochemical Society.