Synthesis and crystal structural analysis of a green light-emitting Ba₅Zn₄Y₈O₂₁:Er³⁺ nanophosphor for PC-WLEDs applications

A series of green light-emitting Ba₅Zn₄Y₈O₂₁:Er³⁺ nanophosphors were prepared via single-step solution combustion process. PXRD-Rietveld investigation revealed that Er³⁺ ions are well-substituted Y³⁺ ions and no major change was observed in the crystalline structure of pure host matrix. Tetragonal nanoparticles with almost no agglomeration were revealed by morphological analysis. Different elements present in the prepared nanomaterials were elucidated via EDAX mapping. Photoluminescence investigation of Ba₅Zn₄Y₈O₂₁:Er³⁺ nanophosphors displayed an intense green emission peak of Er³⁺ ions credited to ⁴S_3/2 → ⁴I_15/2 transition, under NUV excitation of 379 nm. The concentration quenching occurred after 2.0 mol% concentration of the Er³⁺ ions in Ba₅Zn₄Y₈O₂₁ host, thus apprehended it an optimized concentration. CIE coordinates (x, y) of all the prepared nanocrystalline phosphors lied in the green region. Bandgap (E_gap) values of the optimized sample were calculated by analysing the DR spectra of that sample which are found to be 4.0 eV for the pure host and 3.9 eV for the doped sample which lie in semiconductor range. The brief description of all these results proves the importance of synthesized nanophosphors in R-G-B (red–green–blue) PC white light-emitting diodes (WLEDs).