Multifunctional light-emitting materials based on hybrid copper iodide compounds

Abstract

To develop materials for sustainable light-emitting technologies, materials science has to focus on low-cost and earth-abundant emitters. Copper-based materials displaying rich photophysical properties along with low cost and toxicity are able to meet these criteria. In this work, a series of multinuclear copper iodide complexes have been synthesized and characterized. Upon coordination with different phosphine ligands, solubility of the compounds has been achieved in common organic solvents. Structural characterization studies have been conducted using single crystal X-ray diffraction and solid-state NMR. Photoluminescence analyses showed that all materials exhibit yellow emission with high photoluminescence quantum yields. Rationalization of the optical properties is supported by density functional theory calculations. To design processable materials for light-emitting applications, these emitters have been successfully incorporated within polymer materials, thanks to their good solubility properties. In addition to display the room temperature emission properties of the complexes, the resulting composite materials present contrast luminescence thermochromism. The potential of these composites as multifunctional light-emitting materials has been demonstrated through their use as phosphors in light emitting diodes and as inks in anti-counterfeiting systems. This study illustrates the relevance of copper halide materials for the development of multifunctional materials with high potential, based on cost-effective emitters.