Space charge induced augmented dielectric permittivity and improved energy harvesting ability of nano-Ag decorated ZnSnO3 filled PVDF based flexible nanogenerator

Here we report the effect of conducting Ag decoration on ZnSnO3 filler surface on the dielectric and mechanical energy harvesting performance of the resulting PVDF based composite films. The room temperature dielectric permittivity significantly enhanced for Ag@ZnSnO3 loaded PVDF compared to that of the ZnSnO3 loaded PVDF films through the effect of improved space charge polarization after Ag decoration on ZnSnO3 filler. The dielectric permittivity of the composite films was found to be increased gradually with the increase in the Ag concentration on ZnSnO3 filler surface. All the films exhibited low value of dielectric loss ((<)0.05 at 10 kHz) which proved their good applicability in flexible dielectrics. The improved polarization enhanced the mechanical energy harvesting performance of the composite films. The output peak to peak open circuit ac voltage (V-OC) for Ag@ZnSnO3-PVDF (5A10ZS) (with maximum Ag concentration on ZnSnO3 in the present experiment) film after repeated human finger tapping on it was found to be increased to similar to 20 V from a value of similar to 3.5 V and 11 V for neat PVDF and ZnSnO3-PVDF (5ZS) films, respectively. A 10 mu F capacitor was charged to similar to 3.8 V dc after rectification of output V-OC from 5A10ZS sample by 270 s of applied stress on it. During discharging, this dc electrical signal was able to light up some LEDs (connected in parallel) together instantaneously which proved the real life applicability of the nanogenerator device in self-powered flexible electronics.

Automated summary

The effect of Ag decoration on ZnSnO3 filler surface on the dielectric and mechanical energy harvesting performance of PVDF based composite films was investigated in this study. It was found that Ag decoration significantly enhanced the dielectric permittivity and improved the mechanical energy harvesting performance of the composite films.