Efficient Broadband Near-Infrared Emission in the GaTaO4:Cr3+ Phosphor

Efficient broadband near-infrared (NIR) emitting materials with an emission peak centered above 830 nm are crucial for smart NIR spectroscopy-based technologies. However, the development of these materials remains a significant challenge. Herein, a series of design rules rooted in computational methods and empirical crystal-chemical analysis is applied to identify a new Cr3+-substituted phosphor. The compound GaTaO4:Cr3+ emerged from this study is based on the material's high structural rigidity, suitable electronic environment, and relatively weak electron-phonon coupling. Irradiating this new phosphor with 460 nm blue light generates a broadband NIR emission (lambda(em,max) = 840 nm) covering the 700-1100 nm region of the electromagnetic spectrum with a full width at half maximum of 140 nm. The phase has a high internal quantum yield of 91% and excellent thermal stability, maintaining 85% of the room temperature emission intensity at 100 degrees C. Fabricating a phosphor-converted light-emitting diode device shows that the new compound generates an intense NIR emission (178 mW at 500 mA) with photoelectric efficiency of 6%. This work not only provides a new material that has the potential for next-generation high-power NIR applications but also highlights a set of design rules capable of developing highly efficient long-wavelength broadband NIR materials.

Automated summary

This study identified a new Cr3+-substituted phosphor, GaTaO4:Cr3+, with high internal quantum yield and excellent thermal stability. The new compound generates a broadband NIR emission covering the 700-1100 nm region when irradiated with blue light.