Self‐Organized Gold Network–Vanadium Dioxide Hybrid Film for Dynamic Modulation of Visible‐to‐Near‐Infrared Light

Abstract

Composites of phase change material (PCM) and structured metal (SM) are promising templates for photonic applications combining advantages of both insulator–metal transition (IMT) hysteresis and strong light–matter interactions. While significant progress has been made for applications including active modulators, photonic memories, and thermal emitters in the THz‐microwave regime, the fabrication and application of PCM–SM for the visible–near‐infrared (vis–NIR) waves are still limited by the difficulties associated with fabricating nanostructures in a controllable and scalable manner. Herein, a self‐organized gold network–vanadium dioxide hybrid film fabricated by a simple spin‐coating process following the metal deposition, as a litho‐free PCM–SM template in a vis–NIR regime, is demonstrated. Using Fabry–Perot‐type interference, which enhances IMT‐induced refractive index changes, resonance shift of as much as 260 nm and reflection modulation depth of ≈49% in vis–NIR range are then demonstrated. Tuning of the resonance peak from 575 to 950 nm with the control of VO2 thickness, in addition to the manipulation of hysteresis characteristics with the control of self‐organized gold network is also demonstrated. As application examples, thermoactive color film and electrically controlled photonic logic gates in vis–NIR are presented.