The Effect of Nanowire Dimensions on Resonance Frequency of ZnO-Based Nanogenerator

Piezoelectric nanogenerator is a devise that exchanges the kinetic energy to the electrical energy due to the piezoelectric effect. In this paper, effect compressive stress on a single ZnO nanowire as a function of its length and diameter are simulated and studied by COMSOL Multiphysics software. The length and diameter of the nanowire are varied from 1 to 5 μm and 20 to 500nm, respectively. Resonance frequency, open-circuit voltage and short-circuit current are investigated in different lengths and diameters. Results demonstrate that resonance frequency is reduced from 5.37 to 0.501 MHz by increasing in nanowire's length whereas it decreases from 2.17 MHz to 103 MHz by increasing the nanowire diameter. Moreover, rising the height of nanowire enhances both open-circuit voltage and short-circuit current from 0.4 to 1.008 mV and 1.17 to 1.7 mA/cm², respectively. Nevertheless, open-circuit voltage is decreased by increasing in nanowire's diameter from 0.8 mV to 1.2 V, the short-circuit current is enhanced from 48 μA/cm²to 2.6 mA/cm². Consequently, it is possible to design an optimized piezoelectric nanogenerator by varying the length and diameter of the nanowires in nanowire-based nanogenerators to gain maximum output power and adopting to the various environments, according to their resonance frequency.