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

AbstractThe 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.