Highly Luminescent Copper(I) Halide Phosphors Encapsulated in Fumed Silica for Anti‐Counterfeiting and Color‐Converting Applications. Issue 13 (17th April 2022) - Chen, Maosheng
Abstract: Luminescent Cu(I) hybrid materials are currently receiving increasing attention due to their rich photophysical properties with promising phosphors applications. However, the complex synthesis processes usually involving chemotoxic organic solutions largely hinder their practical applications. Herein, the authors introduce the highly luminescent copper(I) halide phosphors encapsulated in fumed silica synthesized via aqueous mechanochemical process. By using different precursors, they obtain blue, green, and orange emission copper(I) halide phosphors with high photoluminescence quantum yields. The green emission is owing to the formation of the well‐known 0D (18‐crown‐6)2 Na2 (H2 O)3 Cu4 I6 (CNCI), while the blue and orange emissions are ascribed to the formation of the novel 1D (18‐crown‐6)2 Na2 (H2 O)3 Cu2 Cl4 (CNCCl) and 0D (18‐crown‐6)2 Na2 (H2 O)3 Cu4 Br6 (CNCBr) crystal structures, respectively. It is demonstrated that waterborne luminescent inks can be directly prepared from those phosphors via blending them with various waterborne polymers. The combination of three primary colors can lead to various spectra with multiple anti‐counterfeiting functions. Further, such phosphors can also be embedded into polystyrene resin to form homogeneous luminescent composites, which can be used to prepare free‐standing luminescent films and fabricate light‐emitting diode (LED) with tunable emissions. This strategy opens a new avenue for the development of low‐cost, highly luminescent phosphors. Abstract : Highly luminescent copper(I) halide phosphors encapsulated in fumed silica are synthesized via aqueous mechanochemical process. The prepared phosphors do not need purification and can be directly blended with various waterborne polymers or polystyrene to form homogeneous luminescent inks for the multiple anti‐counterfeiting, color converting applications and emission tunable light‐emitting diode.