전기적으로 조절 가능한 초방사성 플라즈모닉 나노복합체

Abstract

Plasmonic nanoparticle clusters offer stronger light-matter interactions rather than single nanoparticle, resulting from the collective near-field coupling (superradiance and subradiance) between adjacent nanoparticles, useful for nanophotonic applications in bio-sensing, integrated photonics, and energy harvesting. However, actively tuning the collective coupling of such plasmonic systems is still immature, hindering their practical applications. We here propose active plasmonic nanocomposites with electrically controllable superradiance. The plasmonic nanocomposites consist of gold nanoparticles encapsulated in a conductive polymer (here polyaniline) shell and are self-assembled by coffee-ring effect. The diameter of core nanoparticles and polyaniline state are systematically optimized for controlling both superradiant and subradiant modes via numerical simulation. Furthermore, the superradiant scattering of the composites can be reversibly tuned across over 50 nm wavelength ranges due to the large variation in complex refractive indices of the polyaniline shell.