Bright white light up-conversion luminescence from Yb³⁺/Er³⁺/Tm³⁺ tridoped gadolinium gallium garnet nano-crystals for multicolor and white light-emitting diodes

Gadolinium Gallium Garnet nanophosphors with Yb³⁺/Er³⁺/Tm³⁺ triply-doped ions were synthesized via the Solgel Pechini method and annealed at different temperatures ranging from 800 to 1200 °C. The approximate average crystallite sizes were determined within the range of 26–56 nm by using X-ray diffraction analysis. Color-tunable up-conversion emission was explored in nanomaterials by varying excitation power under 975 nm excitation wavelength by varying excitation power and Tm³⁺ concentration for white light emission. Bright white light up-conversion luminescence from Yb³⁺/Er³⁺/Tm³⁺ tridoped Gd₃Ga₅O₁₂ was recorded. The color quality coordinates for Gd₃Ga₅O₁₂:2%Yb³⁺/1%Er³⁺/1.5%Tm³⁺ nanophosphors annealed at 1000 °C were found to be x = 0.3244, y = 0.3297 at room temperature under 975 nm infrared excitation, which falls within the white zone of the 1931 International Commission on Illumination diagram. Nanophosphors show extreme near-infrared radiation at 800 nm, which is also beneficial to deeper tissue penetration and promotes plants' growth.