Tunable Blue-Yellow Emission in LaInO3:Bi3+,Dy3+ Phosphors via Polyol Synthesis for Advanced LED Applications

Abstract

The polyol synthesis method was employed to prepare LaInO₃ perovskite phosphors doped with Bi³⁺ (x = 1, 3, 5 at.%) and co-doped with Dy³⁺ (y = 1-5 at.%). The X-ray diffraction (XRD) confirmed the formation of a pure orthorhombic LaInO₃ phase in annealed samples. Morphological analysis revealed spherical agglomerates with some irregularities, ranging in size from 60 to 90 nm. The reduction of energy band gap on doping ions into lattice using DFT studies. The energy-dispersive spectroscopy (EDS) confirmed the successful incorporation of Bi³⁺ and Dy³⁺ ions into the LaInO₃ lattice. The photoluminescence (PL) studies demonstrated that Bi³⁺-doped LaInO₃ exhibited a broad blue emission peak at 432 nm due to the ³P₁→¹S₀ transition of Bi³⁺ ions. On the other hand, LaInO₃ doped with Dy³⁺ exhibited distinctive emissions at 482 nm (blue) and 584 nm (yellow), which correspond to the ⁴F_9/2→⁶H_15/2 and ⁴F_9/2→⁶H_13/2 transitions of Dy³⁺ ions, respectively. The optimized sample composition is found to be LaInO₃: 3 at.% Bi³⁺, 3 at.% Dy³⁺ demonstrated enhanced emission intensities due to energy transfer from Bi³⁺ to Dy³⁺ ions making it a promising candidate for advanced LED applications.