Versatile crystallographic and luminescence features of Tb³⁺ activated double perovskite Ba₂BiYO₆ nanophosphor for advanced indoor lighting applications

A series of Tb³⁺-activated double perovskite Ba₂BiYO₆ nanocrystal systems exhibiting a strong green luminescence is produced using an energy-saving solution combustion (SC) method. The crystals formed are found to be cubic and belong to the Fm^-3 m (225) space group with irregular shapes and diameters extending from 43 to 67 nm. Morphological aspects are examined via scanning and transmission electron microscopic (SEM and TEM) techniques. When exposed to UV radiation, the nanocrystals emit a vibrant green light at a wavenumber of 18,281 cm^-1, caused by the transition from the ⁵D₄ → ⁷F₅ electronic state. The effects of energy transfer are also studied. The highest emission intensity was observed at a concentration of 5.0 mol% Tb³⁺ ions when excited at 283 nm. This phenomenon can be attributed to the phenomenon of concentration quenching caused by d–d interactions resulting in a decrease in luminescence intensity. The color coordinates fall within the greenish region and the correlated color temperature (CCT) value is measured 5691 K for optimized sample Ba₂BiY_0.95Tb_0.05O₆ . Consequently, these nanocrystals are well-suited for use in white lighting emitting diodes (WLED) manufacturing, specifically for creating aesthetically pleasing indoor lighting. (author)