Design of a widely adjustable electrochromic device based on the reversible metal electrodeposition of Ag nanocylinders

Structural colors resulting from nanostructured metallic surfaces hold a series of advantages compared to conventional chemical pigments and dyes, such as enhanced durability, tunability, scalability, and low consumption, making them particularly promising for preparing color-tunable devices. However, once these structures are fabricated, they are almost all passive devices with static nanostructures and fixed optical properties, limiting their potential applications. Here, by using a specially designed array of ordered SiO₂ nanoholes as a deposition template in conjunction with the traditional reversible metal electrodeposition device (RMED), we propose a tunable reflective surface where the color of the surface can be changed as a function of the thickness of the deposited Ag nanoparticles (AgNPs). Simplified manufacturability and a large range of color tunability are achieved over previous reports by utilizing the SiO₂ nanohole template, which allows the direct deposition of AgNPs while forming an array structure of Ag nanocylinders. Besides, a further thematic analysis of the physical mechanism in the proposed structure is conducted. The results show that the structural colors induced by the longitudinal localized surface plasmon resonance (LSPR) mode can be dynamically tuned from brown to purple via increasing the deposition thickness. Additionally, in combination with SiO₂ nanohole templates of varying parameters, a full gamut of colors spanning the entire visible spectrum is achieved, revealing the feasibility of utilizing the properties of the LSPR mode for satisfying various color requirements. We believe that this LSPR-based multicolor RMED design will contribute to the development of full color information displays and light-modulating devices.