Low-Temperature Growth of Well-Aligned ZnO Nanorod Arrays by Chemical Bath Deposition for Schottky Diode Application

摘要

A well-aligned ZnO nanorod array (ZNRA) was successfully grown on an indium tin oxide (ITO) substrate by chemical bath deposition at low temperature. The morphology, crystalline structure, transmittance spectrum and photoluminescence spectrum of as-grown ZNRA were investigated by field emission scanning electron microscopy, x-ray diffraction, ultraviolet–visible spectroscopy and spectrophotometer, respectively. The results of these measurements showed that the ZNRA contained densely packed, aligned nanorods with diameters from 30 nm to 40 nm and a wurtzite structure. The ZNRA exhibited good optical transparency within the visible spectral range, with >80% transmission. Gold (Au) was deposited on top of the ZNRA, and the current–voltage characteristics of the resulting ITO/ZNRA/Au device in the dark were evaluated in detail. The ITO/ZNRA/Au device acted as a Schottky barrier diode with rectifying behaviour, low turn-on voltage (0.6 V), small reverse-bias saturation current (3.73 × 10−6 A), a high ideality factor (3.75), and a reasonable barrier height (0.65 V) between the ZNRA and Au.