A Nanoconfinement Strategy for Regulating Cluster Size to Enable Color Tuning in Clustering‐Triggered Phosphorescence

ABSTRACT In clustering‐triggered emission systems, molecules generally form clusters of various sizes, making it difficult to rationally design materials that emit a desired phosphorescence color. We achieved rational tuning of ultralong room‐temperature phosphorescence (URTP) color by hybridizing polystyrene sulfonic acid (PSS), which is a URTP material, with a silica network at varying mixing ratios. The results demonstrate that nanoscale confinement reduces the PSS domain size and thereby controls its phosphorescence color.