Dy3+/Cr4+doped CaLuGaO4 phosphors emitting white and broad NIR light

A phosphor that emits both white light and broad near-infrared (NIR) light is of significant interest across various fields, as it enables both visual inspection and NIR spectroscopic detection. In this study, we designed Dy3+/Cr4+ codoped CaLuGaO4 phosphors that emit both white light and broad NIR light ranging from 1100 nm to 1700 nm when excited at 450 nm. The white light is produced by the 4F9/2 -> 6H15/2, 6H13/2, 6H11/2 transitions of Dy3+. The broad NIR light arises from the 3T2 to 3A2 transition of Cr4+. Additionally, energy transfer from Dy3+ to Cr4+ occurs in the Dy3+/Cr4+ codoped CaLuGaO4 phosphors, allowing for tunable ratios of white light to NIR light by varying the concentrations of Dy3+ and Cr4+. A phosphor-converted light-emitting-diode was constructed by encapsulating the synthesized phosphors around a commercial blue LED chip, demonstrating potential applications in lighting sources and non-destructive spectral analysis.