Enhanced piezo-response in copper halide perovskites based PVDF composite films

In-situ fabricated perovskite nanocrystals in polymeric matrix provide new generation composite materials for plenty of cutting edge technology. In this work, we report the in-situ fabrication of copper halide perovskite (MA(2)CuCl(4), MA:CH3NH3+) embedded poly(vinylidene fluoride) (PVDF) composite films. The optimized MA(2)CuCl(4)/PVDF composite films exhibit greatly enhanced piezo-response in comparasion with pure PVDF films. The enhancements were invesitgated and explained by applying piezo-response force microscopy (PFM) measurements and density functional theory (DFT) caculations. We proposed that the high piezoelectric properties of MA(2)CuCl(4)/PVDF composite films could be related to the large Cu off-centering displacement, the strong interactions between MA(2)CuCl(4) and PVDF as well as large stress concentration around the MA(2)CuCl(4) particles in the films. These piezoelectric composite films are expected to be suitable functional materials for flexible and/or wearable piezoelectrics. (C) 2018 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.