UV-Enhanced Field-Emission Performances of Pd-Adsorbed ZnO Nanorods through Photochemical Synthesis

Abstract

In this work, vertically oriented well-aligned palladium-adsorbed ZnO (PZO) nanorod (NR) arrays were successfully prepared on indium-tin-oxide (ITO) glass substrates via an aqueous solution method with photochemical synthesis. The nanostructures of the PZO NRs were characterized via a field-emission scanning electron microscopy (FE-SEM), a high-resolution transmission electron microscopy (HR-TEM), and the X-ray diffraction (XRD), which revealed that the PZO NRs show a hexagonal wurtzite structure and grew preferentially along the (002) crystal plane. The composition of the adsorbed sample was also confirmed by an X-ray photoelectron spectroscopy and an energy-dispersive X-ray spectroscopy. The PZO NRs exhibited superior field-emission (FE) performance under UV irradiation than in the dark with a low turn-on field value of 5.62 V μm−1 and an enhanced field enhancement factor (β) of 9145.07. It was found that the FE characteristics of the PZO NRs were improved by UV light irradiation, which attributed to generate a large number of electrons.