Perspective Chapter: Vertically Aligned 1D ZnO Nanostructures – Influence of Synthesis Parameters on the Nanomaterials’ Properties

Abstract

Zinc oxide (ZnO) is a widely explored semiconductor metal oxide. This material has interesting properties for several research areas, including energy storage and harvesting, sensing and electronic applications. Its versatility has led to the development of various approaches for synthesizing nanostructures with different morphologies according to the application. In this chapter, a literature review on vapor phase and solution phase synthesis approaches for synthesizing one-dimensional (1D) ZnO nanostructures on different substrates will be provided to establish a comparison between different processes’ parameters. Since hydrothermal synthesis is the most widely used approach for growing ZnO on different substrates due to its simplicity and cost-effectiveness, the principles of this technique will be detailed. As an experimental demonstration of such technique, novel results obtained at CENIMAT on microwave-assisted hydrothermal synthesis of ZnO nanorods, exploring the influence of seed layer thickness, ultraviolet/ozone (UVO) treatment to this layer, and synthesis time and temperature on the nanostructures’ morphology, will be presented. The nanostructures’ length, diameter and density were measured to establish a correlation between synthesis conditions and nanostructures’ features. A seed layer thickness of 100 nm, a 5 min UVO treatment, and a synthesis time and temperature of 60 min and 100°C led to the formation of ZnO nanorods with increased length and aspect ratio.