Abstract
Well-aligned ZnO nanorods (NRs) have been synthesized by chemical bath deposition (CBD) method on (100) p-type Silicon substrate for various growth times. ZnO seed layers have been pre-coated on Si by sol-gel spin-coating process. The effect of growth time on structural, morphological and electrical properties of ZnO NRs were systematically investigated by X-Ray diffraction, scanning electron microscopy and current-voltage measurements at room temperature. SEM images illustrated that vertical, well-aligned, uniformly distributed, dense ZnO NRs were observed to grow on the Si substrate. Moreover, the growth rate decreases dramatically as the deposition time increased. X-ray diffraction pattern showed that the synthesized ZnO NRs have hexagonal wurtzite structure and exhibit a preferred orientation along the c-axis. The current–voltage analysis provided information about electrical parameters of n-ZnO NRs/p-Si heterojunction diode as a function of the growth time. The results showed an increase in the barrier height ϕb and a decrease in the ideality factor n, as the length of the NRs increased. More details about I–V characteristics measured under illumination and in the dark are also reported.
•ZnO nanorods arrays were prepared by a simple and low cost method of sol-gel assisted CBD process.•The synthesized ZnO NRs have hexagonal wurtzite structure and exhibited a preferred orientation along the c-axis direction.•The length-growth rate decreases dramatically as the deposition time increased.•As the growth time increases ideality factor and reverse saturation current decreases whereas barrier height increases.•The I–V characteristics of n-ZnO NRs/p-Si HJs diode have been influenced by varying the length of nanorods.