Down conversation visible emission spectra of Cr³⁺ doped gadolinium aluminium garnet

The preparation of gadolinium aluminium garnet (GAG) doped with Cr³⁺ ions (Cr: GAG) was carried out using the sol–gel technique, followed by sintering at 1100 °C. X-ray diffraction characterization was performed to investigate the effects of Cr³⁺ doping on the GAG phase. The results revealed that Cr³⁺ doping induced strain in GAG, leading to a phase effect and an increase in crystallite size. Field emission scanning electron microscopy was utilized to observe the particle size, morphology, and a comparison of crystallite size with particle size. Fourier transform infrared spectroscopy was used to confirm the interaction between metal and oxygen in the lattice and assess the material's composition. UV spectroscopy and fluorescence spectra were employed to comprehensively study the optical characteristics of Cr: GAG. Chromaticity coordinates, correlated color temperature, and color rendering index were explored at 282 nm excitation. Decay curve analysis revealed that the material’s lifetime increased with an increase in the Cr³⁺ doping concentration in GAG. Fluorescence spectra exhibited multiple peaks, indicating multicolor emission and suggesting the potential for creating efficient white light sources using Cr: GAG. Overall, these findings highlight the potential of Cr³⁺ doping in GAG for tuning the optical properties and creating novel light-emitting energy- efficient materials with promising applications.