Simple Template-Mediated Fabrication of ZnO Nanotube Arrays and Their Application in Flexible Ultraviolet Photodetectors

ZnO, as an important semiconductor, has been extensively studied for a wide range of applications. To date, with the development of micro/nano manufacturing technology, various hierarchical ZnO nanostructures have been fabricated and explored, showing encouraging success in advanced photodetectors. ZnO nanotube structure has a high surface-to-volume ratio, and versatile hollow channels, which are promising for sensing applications. Typical nanotube arrays primarily rely on advanced nanofabrication technologies. Simple and low-cost fabrication strategies are still lacking. Herein, we report a simple template fabrication method to obtain vertically aligned ZnO nanotube arrays. Using flexible, etched polyimide membranes as the template, ZnO nanotube arrays can be prepared in situ by dip-coating the sample into a zinc acetate solution followed by heating. Different hierarchical ZnO nanotube structures were obtained with the nanotube arrays when the method was combined with hydrothermal growth. We have demonstrated that the structures may be used in flexible and transparent photodetectors. Our work provides a facile approach for fabricating ZnO nanotube arrays and expands the application of ZnO nanotube structures to flexible and transparent photodetectors.