Versatile cost-effective fabrication of large-area nanotube arrays with highly ordered periodicity

Nanomaterials typically exhibit physical and chemical properties that differ from those of conventional bulk materials owing to their nanometer-scale structures. Among them, nanotube arrays are characterized by their ability to exhibit remarkably aligned larger surface areas than those of existing arrays. Consequently, they have been used to increase efficiency in various fields such as sensing, energy storage and conversion, and optical communication. Processes such as anodic-aluminum-oxide templating, secondary sputtering, and sputtering are generally used to manufacture nanotube arrays. However, these methods have limitations in creating periodically aligned structures and precisely controlling nanotube characteristics such as diameter, period, and height. Therefore, a method combining direct printing and oblique-angle deposition (OAD) performed by e-beam evaporation is reported in this study for generating nanotubes with a highly ordered periodicity. Using this approach, nanotube arrays of various shapes and specifications can be manufactured by adjusting the type of master stamp used in the direct printing and the OAD parameters. Additionally, this scheme can be leveraged to produce nanotube arrays with metals, inorganic compounds, multilayer structures, and core–shell configurations.