Local Structure Modulation-Induced Highly Efficient Red-Emitting Ba<sub>2</sub>Gd<sub>1–<i>x</i></sub>Y<sub><i>x</i></sub>NbO<sub>6</sub>:Mn<sup>4+</sup> Phosphors for Warm WLEDs
Guixian Li, Xingyang Shi, Xinyue Lu, Qinan Mao, Lang Pei, Yiwen Zhu, Meijiao Liu, Liang Chu, Jiasong Zhong
Abstract
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.