Large-scale, single-oriented ZnO nanostructure on h-BN films for flexible inorganic UV sensors.

We report the growth of large-scale, single-oriented zinc oxide (ZnO) nanowall networks on epitaxial hexagonal boron nitride (h-BN) films and their application to flexible inorganic ultraviolet (UV) light sensors. Using catalyst-free metal-organic vapor phase epitaxy, ZnO nanowall networks with good vertical alignment are grown on epitaxial h-BN films. The single-oriented crystal structure of the ZnO nanostructures on h-BN is investigated using x-ray diffraction (XRD) spectroscopy, and the heteroepitaxial relationship between ZnO and h-BN is revealed through synchrotron radiation XRD. Interestingly, when utilizing the grown ZnO nanostructure as a channel for UV sensors, better performance merits such as a high I_UV/I_dark ratio, faster recovery time, and low dark current are achieved if h-BN is employed as a growth template. As an example of inorganic flexible optoelectronic device applications, flexible UV sensors are fabricated using ZnO/h-BN heterostructures owing to the insulating and transferrable nature of h-BN substrates. The sensor maintained an excellent performance, even under highly bent conditions. [ABSTRACT FROM AUTHOR]