An Extra-Broadband VIS-NIR Emitting Phosphor toward Multifunctional LED Applications

The development of extra-broadband emitting phosphors is challenging but meaningful work. So far, however, phosphors that can be effectively excited by GaN-based blue light-emitting diode (LED) chips and emit from visible (VIS) to near-infrared (NIR) regions are still rare. Herein, this study designs an extra-broadband VIS-NIR emitting phosphor with emission band ranging from 460 nm to 880 nm (bandwidth >400 nm) upon 450 nm excitation, owing to an efficient energy transfer from Ce3+ to the red and NIR emitting Mn2+ ions in Lu2BaAl4SiO12 (LBAS) host. By the analysis of extended X-ray absorption fine structure (EXAFS) spectra and fluorescence lifetimes, it is demonstrated that the NIR emission most probably originates from those Mn2+ occupying the dodecahedral sites with high symmetry rather than the exchange-coupled Mn2+-Mn2+ pairs. Furthermore, two single-phase phosphor-converted LEDs are fabricated by combining blue LEDs with LBAS:Ce3+,Mn2+ phosphors, and thanks to the extra-broadband emission, the resultant devices may realize multifunctional applications, such as in high-quality general lighting, NIR spectroscopy, and plant growth lighting.

Automated summary

The study has successfully designed an extra-broadband VIS-NIR emitting phosphor capable of emitting light from 460nm to 880nm upon 450nm excitation, with efficient energy transfer and potential applications in multifunctional LED devices.