Development of highly sensitive UV sensor using morphology tuned ZnO nanostructures

Abstract

We report synthesis, electrical, optical, and UV sensing properties of morphology tuned one-dimensional ZnO nanostructures. Morphology tuning was achieved by varying the temperature using very simple vapor transport method. The structural, morphological, and compositional properties of the samples were investigated by powder X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and energy dispersive analysis of X-rays spectroscopy. Photoluminescence and diffused reflectance spectroscopy were used to optically characterize films. The structural and morphological features revealed demonstrated that the synthesized nanostructures were high-density crystalline nanowires, nanorods, and nanobelts. Synthesized nanostructures were employed in UV sensing applications. The photosensors exhibit a current response range from 5 to 217 μA for UV light (365 nm) at room temperature. The sensor showed a relatively fast temporal response (0.25–35 s) and baseline recovery time (1–12 s) when irradiated with UV light. Response measurements showed that such a sensor is suitable for use as an optical switch.