Bulk-Size and Highly Transparent Composite Phosphor for NIR Spectroscopy

Near-infrared (NIR) phosphors offer a novel luminescent solution for NIR spectroscopy, but their efficiency remains low. Herein, it is demonstrated that the high transparency of a phosphor improves its external quantum efficiency by developing a new inorganic-organic composite phosphor. The new bulk-size and highly transparent composite phosphor is fabricated through layer-by-layer assembly of micron-sized hexagonal LiSrAlF6:Cr3+ powder phosphor. The inline transparency of the final bulk phosphor can be controlled from 0% to 90.2% at a large solid concentration of & AP;47 vol.%. With high transparency, the new bulk phosphor allows the phosphor-conversion light-emitting diode (pc-LED) a 2.9 times improvement in efficiency. This paper inspires a feasible and low energy consumption method to facilitate next-generation NIR pc-LED phosphors.