A single luminescence center ultra-broadband near-infrared LiScGeO<sub>4</sub>:Cr phosphor for biological tissue penetration
Zejun Ye, Zhijun Wang, Qian Wu, Xiaoxue Huo, Huifang Yang, Yu Wang, Dawei Wang, Jinxin Zhao, Hao Suo, Panlai Li
Abstract
In this work, in order to meet the application of near-infrared phosphor-converted light emitting diodes (pc-LEDs), an ultra-broadband emission phosphor, LiScGeO4:Cr, was synthesized. Its FWHM reaches 335 nm, and its emission spectrum ranges from 800 nm to 1650 nm, which almost covers the entire near-infrared second window (NIR-II). The broadband emission is thought to be caused by the 4T2 → 4A2 transition of the Cr3+ ion. This transition occurs due to the olivine structure of the crystal, which causes the Cr3+ ions to inhabit a low-symmetric crystal field, and the crystal field strength is very weak. NIR pc-LEDs were fabricated by combining a 460 nm blue LED with this phosphor, which penetrates 4 cm thick beef. The results indicate that there may be a potential application for this phosphor in the field of biological tissue penetration and non-destructive testing.