High pyroelectric effect in poly(vinylidene fluoride) composites cooperated with diamond nanoparticles

•Oxygen containing groups on the diamond nanoparticles increase the β-phased content in PVDF.•The thermal conductivities of diamond/PVDF films are enhanced due to the excellent thermal conductivity of diamond.•The enhanced β-phase content and thermal conductivity contribute to the increased pyroelectric signals. In this work, the synthetic diamond nanoparticles are used as the non-ferroelectric fillers to obtain high pyroelectric performance in PVDF composite films. The oxygen-containing groups that inherently exist on the surface of the diamond nanoparticles make more content of PVDF transform from the α-phase to the β-phase, contributing to the high pyroelectric coefficient. The 0.4 wt% diamond/PVDF film shows the highest pyroelectric coefficient of 870,000 μC/cm2K, which is 3.5 times higher than the pristine PVDF. As a result, the diamond/PVDF films generate higher pyroelectric current and voltage than the pristine PVDF film.