Fabrication of flexible nanogenerator with enhanced performance based on p-CuO/n-ZnO heterostructure

A p-CuO/n-ZnO heterostructure was synthesized on an indium tin oxide coated flexible substrate (polyethylene terephthalate) by a simple and low-cost hydrothermal method. Scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction were used to characterize the as-synthesized heterostructure. The results indicated that flower-like CuO nanostructure conformably formed on the ZnO nanorods. Furthermore, a nanogenerator based on the p-CuO/n-ZnO heterostructure was fabricated for harvesting energy from environment, and the output performance of the device was investigated. A larger output current of ~100 nA was obtained in comparison with ZnO based nanogenerator, which could be ascribed to the formation of p–n heterojunctions in the CuO/ZnO composites, reducing the screening effect of excessive electrons. This strategy may provide a highly promising platform for realizing a high-performance flexible piezoelectric energy harvester by new composite piezoelectric material.