Dual mode NIR long persistent phosphorescence and NIR-to-NIR Stokes luminescence in La3Ga5GeO14: Cr3+, Nd3+ phosphor

• Dual mode phosphor with NIR long afterglow and NIR-to-NIR Stokes luminescence.
• Increasing the persistent duration due to the codoping of Nd.
• Avoiding the noteworthy overheating effect due to the strong absorption at 980 nm.

Recently, long persistent phosphors (LPPs) have been considered to be the most prominent candidates for biomedical applications. However, the LPPs suffer from a dramatic decrease in luminescence intensity after incorporation into the tissue. Therefore, it is very necessary to develop the more competitive LPPs and acquire the reproducible tissue imaging. Here, we propose and experimentally demonstrate an effective bifunctional La3Ga5GeO14: Cr3+, Nd3+ phosphor with the interesting characteristic of near-infrared long persistent phosphorescence and NIR-to-NIR Stokes luminescence. Cr3+ and Nd3+ ions are simultaneously selected as the emission centers in order to take advantage of the remarkable phosphorescence properties of Cr3+, and the appropriate energy level characteristic of NIR-excitation band (808 nm) and NIR-emission (1064 nm), and the ability as the brilliant auxiliary to create more efficient defects of Nd3+. The efficient dual-modal emission is, accordingly utilized to realize the convenient, high-resolution global detection and local imaging.