Killing Three Birds with One Stone: Energy Transfer Inducing Efficient, Zero Thermal Quenching, and Emission‐Color Tunable Phosphors

Abstract

AbstractRed emission phosphors with high efficiency and excellent thermal stability are essential for phosphor‐converted light‐emitting diodes (pc‐LEDs). Na2MgPO4F: Mn2+ shows a very weak red emission peak at 615 nm due to 3d–3d forbidden transition. And it exhibits a normal thermal quenching behavior. Blue‐emitting Eu2+ with anti‐thermal quenching (ATQ) is introduced to tune the emission color, emission efficiency, and thermal stability of Mn2+ in Na2MgPO4F. The emission color of Na2MgPO4F: Eu2+, Mn2+ phosphors can be tuned by increasing the Mn2+ content. The internal and external quantum efficiencies of Na2MgPO4F:0.03Eu2+, 0.05Mn2+ are 89.3% and 41.1%, respectively, which are much higher than those of the Mn2+‐doped ones. Furthermore, the ATQ effect of Eu2+ is also transferred to Mn2+ via energy transfer, which results in Na2MgPO4F: Eu2+, Mn2+ phosphors with zero thermal quenching (ZTQ). The cooperation of energy transfer, enhanced absorption, and increased defects amount promotes the achievement of ZTQ in the co‐doped samples. Two white pc‐LEDs with a color rendering index of more than 90 are manufactured by using the as‐synthesized Na2MgPO4F: Eu2+, Mn2+ phosphors combined with near‐UV chips. This study not only provides high‐performance Eu2+, Mn2+ co‐doped phosphors suitable for high‐quality solid‐state lighting, but also exhibits a killing‐three‐birds‐with‐one‐stone strategy to obtain efficient, thermally stable, and color‐tunable phosphors.