Local Structure Modulation-Induced Highly Efficient Red-Emitting Ba₂Gd_1-YNbO₆:Mn⁴⁺ Phosphors for Warm WLEDs

Modulating the crystal field environment around the emitting ions is an effective strategy to improve the luminescence performance of the practical effective phosphor materials. Here, smaller Y³⁺ ions are introduced into substituting the Gd³⁺ sites in Ba₂GdNbO₆:Mn⁴⁺ phosphor to modify the optical properties, including the enhanced luminescence intensity, redshift, and longer lifetime of the Mn⁴⁺ ions. The substitution of smaller Y³⁺ ions leads to lattice contraction and then strengthens pressure on the local structure, enhances lattice rigidity, and suppresses nonradiative transition. Moreover, the prototype phosphor-converted light-emitting diode (LED) demonstrates a continuous change photoelectric performance with a correlated color temperature of 4883-7876 K and a color rendering index of 64.1-83.2, suggesting that it can be one of the most prospective fluorescent materials applied as a warm red component for white LEDss. Thus, the smaller ion partial substitution can provide a concise approach to modulate the crystal field environment around the emitting ions for excellent luminescence properties of phosphors toward the modern artificial light.