Height‐Gradiently‐Tunable Nanostructure Arrays by Grayscale Assembly Nanofabrication for Ultra‐realistic Imaging

Abstract

AbstractDue to the limitation of nanofabrication technology, nanostructured arrays and devices are usually of equal height, and it is difficult to change simultaneously its height in the Z direction at X–Y direction regulation. However, the tunable height as an indispensable part of structural spatial freedom control is very conducive to the functional expansion and innovation of nanodevices. Here, a grayscale assembled fabrication method is developed by combining e‐beam lithography with atomic layer deposition and transfer technology, and a wide range of the height gradient of nanostructures can be realized in the same array and then applied in high‐quality images. Following this strategy, ultra‐realistic relief‐nanostructured images with 256 grayscale levels are demonstrated, consisting of height‐varying nanopillars with 100 nm in pixel size and 6.4×1010 dpi in resolution. Especially, multi‐dimensional structural color based on metasurfaces with C4 symmetric pixels is designed and prepared by height regulation nanofabrication, enabling a strong multi‐dimensional control ability in hue, saturation, and brightness of the structural color display with the single pixel of 1.5 µm in size. The as‐developed grayscale nanoconfigurations open a new approach for multidimensionally structural regulations, showing great applied potential not only in high‐resolution imaging but also in more advancednanophotonic devices.