Regulation of Anti-Thermal Quenching and Emission Color in Eu2+-Activated Na-Beta-Alumina Phosphors for Full-Spectrum Illumination

Broadband cyan-emitting phosphors are crucial to close the cyan gap of phosphor-converted white light-emitting diodes (pc-WLEDs) for full-spectrum illumination. In this work, efficient cyan-emitting Eu2+ -activated phosphor is achieved through structural modulation, which exhibits anti-thermal quenching behavior. Redshift from blue (469 nm) to cyan (500 nm) emission and enhancement of emission is achieved by codoping Mg(2+ )and Ge4+ into Eu2+ -activated Na-beta-alumina phosphor. The introduction of Mg2+ ions dominates the redshift, while Ge4+ dominates the enhancement of emission. Furthermore, the introduction of Mg2+ and Ge(4+ )reduces the content of deep trap levels related to VNa defect, which decreases the degree of anti-thermal quenching and results in better thermal stability. The prototype pc-WLED by using the cyan-emitting phosphor exhibits higher color-rendering index and potential to close the cyan gap of pc-WLEDs for full-spectrum illumination. This work presents a paradigm for exploring phosphors with highly efficient and thermally stable emissions.

Automated summary

Efficient cyan-emitting phosphor with anti-thermal quenching behavior is achieved through structural modulation and codoping Mg2+ and Ge4+. The introduction of Mg2+ dominates the redshift while Ge4+ enhances the emission. This work presents a paradigm for exploring highly efficient and thermally stable phosphors.