Broadband NIR Phosphor Ca<sub>2</sub>LuScAl<sub>2</sub>Si<sub>2</sub>O<sub>12</sub>:Cr<sup>3+</sup> for NIR LED Applications
Ye Jin, Zhen Zhou, Rongxia Ran, Shuang Tan, Yongfu Liu, Jinju Zheng, Guotao Xiang, Li Ma, Xiaojun Wang
Abstract
Abstract Near‐infrared phosphor‐converted light‐emitting diodes (NIR pc‐LEDs) have promising applications in food analysis, night vision imaging, and biological probes. Developing NIR phosphors with broadband emission and high efficiency has attracted immense interest. Herein, a novel NIR phosphor Ca 2 LuScAl 2 Si 2 O 12 :Cr 3+ (CLSAS:Cr 3+ ) is reported for the first time. Under the excitation of 442 nm light, CLSAS:Cr 3+ shows broadband emission from 600 to 900 nm with a full width at half maximum (FWHM) of 142 nm, benefiting from the emissions of two Cr 3+ centers in CLSAS, which is proved by the spectra and the decay curves. The internal quantum efficiency (IQE) of 73.7% is achieved and, at 423 K, the emission intensity maintains 76% of the value at room temperature. Combining the CLSAS:Cr 3+ phosphor and the 450 nm blue chip, the NIR pc‐LED is fabricated and demonstrated for fast imaging of veins in human palm and fist, as well as night vision for objects.