Precise control of photoemission and circularly polarized emission achieved through resonant coupling of chiral nanoparticles with Ag particles

Chiral materials that possess circularly polarized luminescence (CPL) functionality along with up- and down-conversion luminescence properties present promising research opportunities. However, achieving materials that simultaneously exhibit high luminescence emission efficiency across the visible to near-infrared range while also demonstrating CPL activity remains a significant challenge. Here, we achieve a significant enhancement of luminescence from the visible to near-infrared range as well as modulation of upconversion circularly polarized luminescence (Up-CPL) through the resonant coupling of silver nanoparticles with chiral nanoparticles. Our results show that silver nanoparticles excited by 980 nm light generate localized surface plasmon resonance (LSPR), creating a concentrated electromagnetic field at their surface. The electromagnetic field interacts with the chiral material, amplifying the strength of the chiral field, hereby enhancing the intensity of luminescence from the visible to near-infrared. This study presents a novel approach for enhancing visible to near-infrared luminescence intensity and realizing circularly polarized luminescence by using rare-earth-doped chiral inorganic materials coupled with Ag nanoparticles.