Thermal quenching properties of narrow-band blue-emitting MBe2(PO4)2:Eu2+(M = Ca, Sr) phosphors towards backlight display applications

作者：Hu, Tao; Gao, Yan; Ji, Xiaohong; Xia, Zhiguo^*; Zhang, Qinyuan^*

来源：Inorganic Chemistry Frontiers, 2020, 7(14): 2685-2691.

DOI：10.1039/d0qi00467g

• STRUCTURAL DESIGN
• LUMINESCENCE
• LIGHT
• EU2+
• PHOTOLUMINESCENCE
• EFFICIENT

Discovering new phosphors with narrow-band emission is critical for white light emitting diodes (LEDs) in liquid-crystal displays (LCDs). Herein, near-ultraviolet (UV) excitable narrow-band blue-emitting MBe2(PO4)(2):Eu2+(M = Ca, Sr) phosphors were successfully designed, exhibiting an extremely narrow full width at half-maximum of similar to 26-27 nm, high color purity of similar to 99.1%, small Stokes shift of similar to 1500 cm(-1), desirable photoluminescence quantum efficiency of similar to 63.4%, and zero thermal quenching even at temperatures up to similar to 300 degrees C. The small Stokes shift and narrow emission profile are fundamentally caused by the greatly suppressed structural relaxation benefiting from the rigid and ordered connected [BeO4] and [PO4] tetrahedra network. Meanwhile, the unprecedented thermal emission behavior is ascribed to the suppression of thermally activated photoionization and the non-radiative pathway from the cross-point of the 5d excited state to the 4f ground state of Eu2+. A wide color gamut reaching up to 88.6% NTSC is realized, demonstrating the validity of MBe2(PO4)(2):Eu(2+)in LED backlights for LCDs. The present studies encourage researchers to identify hitherto undiscovered narrow-band phosphorsviaselecting a stiff and ordered host with confined sites for doped rare earth activators.