Surface modification and fabrication of 3D nanostructures by atomic layer deposition

Atomic layer deposition (ALD) not only presents a direct way to prepare nanomaterials when combined with templates, but also allows surface engineering to fine-tune the properties of the material. Here, we review recent progress in the field of nanostructured materials and devices that have been fabricated by ALD. Various materials, including semiconducting, magnetic, noble metallic, and insulating materials, can be used to form three-dimensional (3D), complex nanostructures with controlled composition and physical properties. We begin this review with ALD nanomaterials that can be prepared from porous templates with a 2D pore arrangement, such as anodic aluminum oxide, and advance toward opal structures with a 3D pore arrangement. We also discuss surface engineering by ALD on existing nanowires/nanotubes, devices, and chemical patterns that has the potential for application in high-performance transistors, sensors, and green energy conversion. Finally, we provide perspectives for future device applications that could arise from ALD nanomaterials.