Preparation of ZnO nanoflakes and a nanowire-based photodetector by localized oxidation at low temperature

This investigation proposes a novel, simple, and quick technique for fabricating ZnO nanoflakes and nanowire-based photodetector devices. High-density ZnO nanoflakes and nanowires were synthesized on a glass substrate by localized oxidation at a low temperature of 300°C. The synthesized ZnO nanoflakes and nanowires were polycrystalline and had nanometer dimensions, according to X-ray diffraction and field-emission scanning electron microscopy. A green emission band centered at 512 nm dominated the cathodoluminescence spectrum of ZnO nanoflakes and nanowires. The Zn pad and ZnO nanostructures had good ohmic contacts, as revealed by the measured I-V curve. Measurements of the transient response demonstrated that the rise time and fall time constants of the photodetector were 20.35 and 3.9 ms, respectively.