Ba-doped ZnO nanorods: Efficient piezoelectric filler material for PDMS based flexible nanogenerator

Abstract

We report the synthesis of pure and Ba-doped ZnO nanoparticles by chemical co-precipitation technique with the aim to study the viability of Ba-doped ZnO nanoparticles as piezoelectric fillers in composite piezoelectric nanogenerators. The influence of Ba-doping on the structural, ferroelectric and piezoelectric properties of ZnO has been investigated in detail. Structural study by powder XRD reveals the formation of single hexagonal wurtzite phase for both pure and Ba-doped ZnO nanoparticles. Hexagonal rod-like morphology has been observed for both the samples from field emission scanning electron microscopy. The ferroelectric properties of Ba–ZnO have also been investigated and the remnant polarization and coercive field was measured to be 0.049 μC/cm2 and 4.088 kV/cm. In addition, Ba–ZnO sample shows a typical butterfly curve and the average d33 value of 41.28 p.m./V. Owing to improved piezoelectric properties and reduced leakage current, Ba–ZnO nanorods were utilized for the fabrication of flexible PDMS polymer based nanogenerators. A series of nanogenerators were fabricated with different amounts of Ba–ZnO filler varied from 10 to 40 wt% to individuate the optimal nanofiller concentration. The device with 30 wt% of Ba–ZnO generated the maximum open-circuit output voltage of about 10.5 V upon perpendicular compression of 2 kgf. Thus, Ba–ZnO:PDMS based composite device can be explored for application in mechanical energy harvesting and driving portable electronics.