Improvement of thermal stability and luminescence in La3ZrxSn1−xGa5O14:0.015Cr3+ by the substitution of Zr # Sn and its application in level detection, biomedical imaging and night vision monitoring†

Although there has been a considerable amount of research on near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs), narrow-band emission and poor thermal stability continue to be problems associated with NIR phosphors. To solve these problems, La₃Zr_xSn_1−xGa₅O₁₄:0.015Cr³⁺ phosphors with ultra-broadband NIR emission were obtained by partially replacing Sn⁴⁺ with Zr⁴⁺ through a strategy of multiple lattice site occupancy and cationic modulation, which altered the crystal field environment of the material. The spectrum was broadened, and the luminous intensity and thermal stability of the material were successfully improved. Finally, the phosphor was combined with a blue LED chip package, and the broad prospects of the phosphor in the NIR application field were proved by experiments of level detection, biomedical imaging, and night vision monitoring.