Extraordinary broadband near-infrared emission in Cr3+-doped ScTa0.5Nb0.5O4 with two selective doping sites

The versatile applications of Cr³⁺-doped near-infrared (NIR) phosphors rely on their ultra-broadband tunable photonics. Herein, a serious of Cr³⁺-doped ScTa_0.5Nb_0.5O₄ (STNO) phosphors with layer arranged [ScO₆] and [Ta/NbO₆] octahedral structure were synthesized and investigated with density functional theory (DFT) calculation and experimental characterizations. Cr³⁺ was confirmed with two selective doping sites in STNO host. Based on the co-substitution strategy to regulate the crystal field, extraordinary broadband NIR emission covering 800–1400 nm region with a full width at half maximum (FWHM) of 192 nm has been achieved upon 430 nm blue-violet light excitation. The potential application of this extraordinary broadband NIR phosphor in night vision area is validated by fabricating a NIR pc-LED. This work not only provides new NIR phosphors with extraordinary broadband emissions but also highlights the co-substitution strategy and crystal field regulation capable of developing long-wavelength broadband NIR materials for high-performance NIR pc-LEDs applications.