Color-Tunable Emission of ZnO/Ag₂O/MnO₂ Nanocomposite Phosphor for Solid-State Lighting Applications

For ecologically friendly and energy-efficient solid-state light sources, phosphors with low color-correlated temperatures (CCTs) and high color rendering indices (CRIs) are greatly desired. Herein, a co-precipitation method is used to modulate the fluorescence color of ZnO nano-material for bright multi-color light emitting diodes (LEDs) applications. The structural, thermal, morphological and optical properties of ZnO nanomaterials have been studied. Thermogravimetric analysis (TGA) of the as-synthesized nanomaterials reveals their good thermal stability whereas XPS analysis confirms their chemical states. We demonstrate that after combining ZnO with Ag2O and MnO2, the nanocomposite can attain extraordinary luminous tunability as realized by the photoluminescence (PL) properties of the nanomaterials. The estimated Commission Internationale de l'Eclairage (CIE) color coordinates indicate that ZnO, the blue color phosphor can be tuned to orange-red color phosphor (ZnO/Ag2O and ZnO/MnO2) and to white color phosphor (ZnO/Ag2O/MnO2) exhibits fairish color rendering index (CRI) of 84, after composited with Ag2O and MnO2. Finally, the ZnO/Ag2O, ZnO/MnO2 and ZnO/Ag2O/MnO2 nanocomposites have the potential to be utilized as phosphor materials in warm white LED applications because of their extremely pure, robust stability and tunable emission colors. Our findings can be used as a new benchmark for the identification of new phosphors and the tunability of their luminescent color for solid-state lighting applications.