Achieving zero-thermal quenching of Al2(WO4)3:Eu,Tb red phosphors with low thermal expansion for LEDs

Minimizing the emission loss with rising temperature is important to fundamental research and technological applications of phosphor-converted white light-emitting diodes (pc-WLEDs). Red phosphor materials are crucial for improving the illumination and backlit display quality of pc-WLEDs. In this work, non-hygroscopic Al2(WO4)3:0.05Eu3+,0.05 Tb3+ (AWO:0.05Eu,0.05 Tb) red phosphors with low positive thermal expansion are successfully developed to simultaneously achieve zero thermal quenching (ZTQ) and a highly efficient red emitting. Under the optimal 397 nm NUV light excitation, AWO:0.05Eu,0.05 Tb exhibited a strong red emission at 618 nm with a high color purity (CP) of 99.71 % and a high internal quantum efficiency (IQE) of 80.24 %. Furthermore, a warm pc-WLED device with suitable color coordinates (0.347, 0.317), high color rendering index (CRI = 90.2) and low color correlated temperature (CCT = 4737 K) was fabricated based on the as-prepared red phosphor AWO:0.05Eu,0.05 Tb. The findings suggest that the proposed phosphor holds significant promise as a red component for high-power warm pc-WLEDs, which may open up new ways for the exploration of high-performance lanthanide-activated red phosphors towards versatile applications.