Killing Three Birds with One Stone: Energy Transfer Inducing Efficient, Zero Thermal Quenching, and Emission‐Color Tunable Phosphors
Jiali Tang, Xinyu Zhang, Shuzhen Liao, Yunfei Zhu, Yue Han, Hui Su, Zhongxian Qiu, Shixun Lian, Jilin Zhang
Abstract
Abstract Red emission phosphors with high efficiency and excellent thermal stability are essential for phosphor‐converted light‐emitting diodes (pc‐LEDs). Na 2 MgPO 4 F: Mn 2+ 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 Eu 2+ with anti‐thermal quenching (ATQ) is introduced to tune the emission color, emission efficiency, and thermal stability of Mn 2+ in Na 2 MgPO 4 F. The emission color of Na 2 MgPO 4 F: Eu 2+ , Mn 2+ phosphors can be tuned by increasing the Mn 2+ content. The internal and external quantum efficiencies of Na 2 MgPO 4 F:0.03Eu 2+ , 0.05Mn 2+ are 89.3% and 41.1%, respectively, which are much higher than those of the Mn 2+ ‐doped ones. Furthermore, the ATQ effect of Eu 2+ is also transferred to Mn 2+ via energy transfer, which results in Na 2 MgPO 4 F: Eu 2+ , Mn 2+ 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 Na 2 MgPO 4 F: Eu 2+ , Mn 2+ phosphors combined with near‐UV chips. This study not only provides high‐performance Eu 2+ , Mn 2+ 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.