Fabrication and characterization of piezoelectric nanogenerator based on Al/ZnO/Au structure

The purpose of this research work is to harvest energy using the piezoelectric properties of ZnO nanowires (NW). Fabrication and characterization of the piezoelectric nanogenerator (NG), based on Al/ZnO/Au structure without using hosting layer, were done to harvest energy. The proposed method has full potential to harvest the cost-effective energy.

ZnO NW were fabricated between the thin layers of Al- and Au-coated substrates for the development of piezoelectric NG. To grow ZnO NW, ZnO seed layer was prepared on the Al-coated substrate, and then ZnO NW were grown by aqueous chemical growth method. Finally, Au top electrode was used to conclude the Al/ZnO/Au NG structure. The Al and Au electrodes were used to establish the ohmic and Schottky contacts with ZnO NW, respectively.

Surface morphology of the fabricated device was done by using scanning electron microscopy, and electrical characterization of the sample was performed with digital oscilloscope, picoammeter and voltmeter. The energy harvesting experiment was performed to excite the presented device. The fabricated piezoelectric-sensitive device revealed the maximum open circuit voltage up to 5 V and maximum short circuit current up to 30 nA, with a maximum power of 150 nW. Consequently, it was also shown that the output of the fabricated device was increased by applying the stress. The presented work will help for the openings to capture the mechanical energy from the surroundings to power up the nano/micro-devices. This research work shows that NGs have the competency to build the self-powered nanosystems. It has potential applications in biosensing and personal electronics.

The fabrication of simple and cost-effective piezoelectric NG is done with a structure of Al/ZnO/Au without using hosting layer. The presented method elucidates an efficient and cost-effective approach to harvest the mechanical energy from the native environment.