Improved Near-Infrared Luminescence Properties of LiScSi2O6:Cr3+,Yb3+ Phosphors via Efficient Energy Transfer

Developing high-performance broadband near-infrared (NIR) phosphors for NIR phosphor-converted light-emitting diodes is still a challenge. Co-doping is an effective strategy for enhancing the performance of NIR phosphors. Herein, we explore a NIR phosphor by co-doping Yb 3+ into LiScSi 2 O 6:Cr 3+ (LSS:Cr 3+ ). Under 468 nm excitation, LSS:Cr 3+,Yb 3+ exhibits a broad NIR emission from 700 to 1100 nm. Due to the efficient energy transfer from Cr 3+ to Yb 3+, the maximum bandwidth of LSS:Cr 3+,Yb 3+ reaches 219 nm, broader than that of LSS:Cr 3+ (170 nm). The addition of Yb 3+ further suppresses the thermal quenching compared with that of the Cr 3+ singly doped specimen. At 150 °C, LSS:Cr 3+,Yb 3+ retains 62% of the emission intensity at room temperature, while that of singly doped LSS:Cr 3+ is only 40%. These results indicate that the construction of Cr 3+ → Yb 3+ energy transfer not only can broaden the emission spectrum but also can improve the thermal stability.