Plasmonic Tamm Resonance in a Conjugated‐Polymer Biointerface for Efficient Cell Photostimulation

Abstract Plasmonic resonances offer a powerful way for confining light and amplify interactions at materials interfaces. Among them, Tamm plasmons that arise at the interface between a metal film and a photonic crystal are particularly attractive because they can be excited at normal incidence and support strong field localization. In the specific case of porous or corrugated metal layers, the resonance field can extend to the metal/air interface, where it becomes accessible to overlying materials. Here, a Tamm plasmon device (TD) is introduced fabricated by depositing a corrugated silver layer on a SiO ₂ /TiO ₂ mesoporous distributed Bragg reflector, and tuned to support a Tamm plasmon resonance at 575 nm to enhance light–matter interaction at the bioelectronic interface to maximize cell photostimulation. The TD enhances polymer absorption, influences emission and photothermal response. When interfaced with living cells, this translates into efficient light‐driven depolarization at reduced excitation intensity. By concentrating evanescent fields at the polymer interface and acting as an asymmetrical open resonant cavity, the TD architecture markedly lowers the optical energy threshold for cell photostimulation. This versatile platform offers new opportunities for low‐power photothermal therapies, neuromodulation, and advanced optoelectronic applications.