Ultra-broadband NIR-I/II-emitting Ca4HfGe3O12:Cr3+, Yb3+garnet phosphors for organic material analysis

Broadband near-infrared (NIR) phosphor-converted light emitting diodes (pc-LED) are a promising next-generation light source for smart NIR spectroscopy. However, Cr3 +-excited NIR phosphors only cover the NIR-I region (before 900 nm), limiting their applications. The development of including efficient NIR-I and NIR-II emission materials is crucial for advancing NIR lighting and related technologies. This study develops a broadband NIR phosphor by incorporating Cr3 +-Yb3 + ion pairs into Ca4HfGe3O12. When excited by 468 nm blue light, the Ca4HfGe3O12:Cr3 +, Yb3 + phosphor emits broadly from 700 to 1200 nm, peaking at 1010 nm with a FWHM of 253 nm. The Cr3+-Yb3+ energy transfer (ET) enhances the luminescence properties, thermal stability, and the phosphor's internal quantum efficiency (IQE). Furthermore, the NIR LED prototype demonstrates its potential for applications in night vision lighting, nondestructive testing, and organic material analysis. This study presents an ultra-broadband NIR material with great application potential, offering a novel option for next-generation compact NIR sources.