High-performance Non-porous P(VDF-TrFE) Film Preparation and Its Application to Flexible RF Devices

P(VDF-TrFE) has a good potential for flexible electronics application owing to its good piezoelectric performance and excellent flexibility. However, high density of pores and large surface roughness of the material cause the high loss of acoustic waves, limiting its use in bulk acoustic devices. In this paper, a simple method is proposed to effectively remove the pores inside the P(VDF-TrFE) film and reduce the surface roughness yet maintaining the piezoelectric properties of the film. The obtained thin film possesses excellent properties and characteristics: much improved breakdown strength of >300kV/mm; very high $\beta-$phase content, >80% and extraordinarily high piezoelectric coefficients, d 33 =S0pm/V. By utilizing this high-performance film, we have successfully fabricated flexible FBAR devices and obtained good performance.