An Unlimited Color Palette from Perylene Derivative Molecules Dispersed within Hybrids

Subject to the aggregation-caused quenching mechanism in the solid state, perylene and its derivatives turn out to be fascinating organic fluorophores when separated from each other by their cointercalation within a layered double hydroxide host structure. Such accommodation with surfactant spacers limits their stacking usually caused by π–π interaction between neighboring cores. For each series of fluorophores having substitution in bay or diimide positions, an optimized composition is selected based on optical performances and in particular on the absolute photoluminescence quantum yield. The optimal relative quantity of phosphor is very low from 0.001 to 0.1% of the total anionic capacity. When dispersed into a silicone matrix, the loaded films cover from green (510 nm) to red (625 nm) emission depending on the perylene derivative molecules. With loaded films overlaid on a blue chip, a warm white light (color-correlated temperature = 3890 K) with a color-rendering index as high as 91.1 is reached. In such a light-emitting diode configuration, the superposition of films for each fluorophore is preferred to the powder mixture or to the cointercalation of organic phosphors within the same structure in order to avoid too strong and nonpredictable reabsorption phenomena between emitting centers.