Facile synthesis of solid-state fluorescent organosilica nanoparticles with a photoluminescence quantum yield of 73.3% for fingerprint recognition and white-light-emitting diodes

Silicon-based fluorescent nanomaterials have attracted widespread attention in latent fingerprint detection and white light-emitting diodes (WLEDs) due to their high photoluminescence, low toxicity and good stability. However, it is still challenging to fabricate solid-state silicon-based nanomaterials with a high quantum yield because of their severe emission quenching properties. Herein, one-step hydrothermal synthesis of polymer-like coated organosilica nanoparticles (OSiNPs) with strong blue luminescence emission by using N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO), zinc chloride and sodium citrate as precursors is reported. The self-quenching-resistant polymer-like coated OSiNP powder can be easily obtained by ethanol precipitation and oven drying, and the absolute photoluminescence quantum yield (PLQY) can reach up to 73.3%. The possible formation mechanism of polymer-like coated OSiNPs is proposed. Because of the strong solid-state fluorescence, the OSiNP powder can be successfully applied in rapid latent fingerprint detection with enhanced imaging on various substrate surfaces and integrated with commercial phosphor on UV chips to fabricate WLEDs.