Elucidations on the Effect of Lanthanum Doping in ZnO Towards Enhanced Performance Nanogenerators

Abstract

Energy harvesting using semiconducting piezoelectric materials is one of the key areas of current research due to its high biocompatibility, low impedance, and high temperature workable range. In this work, we have optimized the doping of Lanthanum in ZnO towards the realization of enhanced output nanogenerator. We have varied the percentage of lanthanum (0, 1, 2.5, 5 and 7.5%) in the ZnO and systematically studied the piezoelectric response of each device. The piezoelectric output improved three to fourfolds by the incorporation of Lanthanum above 2.5%. The voltage response was further escalated by the controlled annealing in an oxygen environment. The doped and annealed device show eight to ninefolds improved output (~ 13.5 V) compared to the intrinsic device (~ 1.6 V). Material properties were investigated thoroughly along with the piezoelectric using various characterization tools. The device show a high maximum power density (~ 2.5 mW/m2) and was used to charge several commercial capacitors. Finally, the device was demonstrated to work in intruder-safety alarm system application as low-cost device. © 2019, Korean Society for Precision Engineering.