Subwavelength nanocavity for flexible structural transmissive color generation with a wide viewing angle

Abstract

We present a high angular tolerant structural coloration based on strong interference effects in a nanocavity patterned at a subwavelength scale on a flexible substrate. The structural colors, fabricated over a large area by nanoimprint lithography, feature a non-iridescent performance over a wide angle of incidence up to 60°, which is of great importance to various applications, such as imaging sensors and colored display systems. In addition to the non-iridescence, the transmissive colors of the proposed structure, simply consisting of triple layers, can be tuned with ease by altering a duty cycle of nanostructures, thus enabling the creation of individual RGB colors in a pixel unit via a facile one-step approach. Moreover, it is confirmed that their performances remain unchanged to the 10 mm bending radius condition, and the encapsulation effects of a polymer material on their optical properties are investigated for practical usage. The presented strategy could provide a new avenue for achieving improved efficiency and desired functionality, thereby opening the door to many potential applications, including anti-counterfeit tagging, imaging sensor systems, and color e-paper displays.