Efficient CrIII Ion Governed Energy Migration for Broadband Near-Infrared Emission in Ca3Sc2Ge3O12 Garnet Phosphor

Graphical The Ca3Sc2Ge3O12:Cr3+ NIR emission garnet phosphor exhibits broadband emission peaking at 817 nm with a FWHM value of 128 nm. The developed phosphor presents balanced comprehensive performance and is suitable for NIR-LED application. The rapid growth in phosphor-converted near-infrared light-emission diodes (NIR-LEDs) has led to the development of NIR emitter with high efficiency, broadband emission and high thermal stability. In this work, an efficient broad NIR emission of Cr 3+ in novel Ca 3 Sc 2 Ge 3 O 12 (CSGO) garnet-based host was developed for the first time, which located at 700 to 1000 nm peaking at 817 nm with a broad bandwidth of ~128 nm. Such a broadband NIR emission originated from the preferential occupancy of Cr 3+ in Sc 3+ sites with weak octahedral field, which was manifested by the luminescence spectrum and decay behaviors. The Cr 3+ -doping concentration was regulated to achieve a good internal quantum efficiency (IQE) of 72.1 % and a fantastic thermal stability (at 423 K, sustained approximately 85 % of the initial intensity). The mechanism for concentration and thermal quenching was further investigated. Benefiting from the excellent luminescence features, a prototype NIR-LEDs was assembled via integrating the optimized samples with commercial blue InGaN LED chips, which exhibited a satisfactory photoelectric property and a brilliant performance in night vision. These results demonstrated the as-obtained sample to be a great potential candidate for NIR-LEDs.