Substantial enhancement of optoelectronics and piezoelectric properties of novel hollow ZnO nanorods towards efficient flexible touch and bending sensor

Abstract

The novel solid and hollow ZnO nanorods were prepared by chemical synthesis approach. The hollow ZnO NRs show a large optical band gap as compared to the solid ZnO NRs which is attributed to quantum confinement effect. The unique emission spectra of hollow ZnO NRs show an exceptional ability for visible emission as compared to solid ZnO NRs owing to unique hollow structure, which enhanced multiple scattering. The piezoelectric potential of hollow nanorod shows about 3.75 times higher peizopotential than the solid nanorods with length (a = 200 nm) and height (h = 1000 nm). The piezoelectric potential was found to be increased with the height of nanorod with a fixed length. Interestingly, the piezoelectric potential increases with decreasing wall thickness in hollow nanorod. The hollow ZnO NRs-based touch sensor shows five times higher piezoelectric response as compared to the solid ZnO NRs. These results provide valuable information for future studies aimed at improving the piezoelectric properties of hollow nanostructures for potential applications in energy harvesting and sensing.