Enhanced dielectric, ferroelectric and piezoelectric performance of Nd-ZnO nanorods and their application in flexible piezoelectric nanogenerator

Pure and Neodymium (Nd) doped ZnO nanorods were prepared using cost effective wet chemical co-precipitation method and used for the fabrication of flexible piezoelectric nanogenerator. The structure and morphology of ZnO and Nd-ZnO samples were studied using powder X-ray diffraction, FESEM and TEM techniques. Ferroelectric measurements showed a remanent polarization (Pr) of ∼0.064 μC/cm2 and coercive field (Ec) of ∼6.04 kV/cm, respectively at 600 V. Leakage current density was found to be reduced after Nd doping in ZnO nanorods. Enhanced Curie temperature (Tc = 125 °C) and large piezoelectric coefficient (d33 = 512 pm/V) were observed in Nd doped ZnO nanorods, which makes Nd-ZnO a better candidate for piezoelectric energy harvesting and high temperature nano-storage devices. Moreover, flexible piezoelectric nanogenerators (PENGs) were fabricated using ZnO and Nd-ZnO nanorods. The Nd-doped ZnO based NG showed high piezoelectric performance by generating average voltage of ∼31 V under finger tapping (∼0.3 N), which was more pronounced in comparison to ZnO based NG (∼2 V).