Synthesis of Broad Excitation Fluorescent Microspheres Based on Clusteroluminescence and Their Application in Anti‐Counterfeiting and LED

Abstract

AbstractThe nonconventional polymer luminophores (NPLs) with white emission are scarce due to the challenges in regulating their clustering structures. In this work, polystyrene is employed to develop a new kind of broad‐emitting clusteroluminescence (CL) through suitable cross‐linking and sulfonation. The sulfonated porous poly(styrene‐co‐divinylbenzene) microspheres (SPDMs) exhibit broad emission spectra (400–700 nm) in the visible light region. Further characterization and theoretical calculations show that through‐space conjugation (TSC) enhanced with high cross‐linking and sulfonation degrees (SD) is the main factor affecting the luminescence of microspheres. Monodisperse SPDMs with a low fluorescence distribution (CV < 5%) across 13 flow channels. Additionally, SPDMs microspheres is employed to construct binary, Cu2+, and pH‐responsive microarrays to encrypt and decode important information. Finally, SPDMs are developed for utilization as single‐component white and warm white light‐converting light emitting diodes (LEDs). These LEDs demonstrate Commission International de L’Eclairage (CIE) coordinates and correlate color temperatures (CCT) of (0.31, 0.321) and (0.383, 0.41), 6611 and 4100 K, respectively. Notably, the color rendering index (CRI) value for SPDMs‐50‐2 in white LED applications reaches an impressive 92. This study provides an economical, simple, and effective design strategy for developing NPLs with both monodispersity and broad emission.