Enhancement of the NIR Emission of Cr<sup>3+</sup>–Yb<sup>3+</sup> Co-doped La<sub>3</sub>GaGe<sub>5</sub>O<sub>16</sub> Phosphors by Doping Nd<sup>3+</sup> Ions via Efficient Energy Transfer for NIR Spectroscopy Regulation
Feiyue Fan, Shuaishuai Yu, Yanyan Li, Yixuan Xu, Yunmei Song, Yingjuan Yan, Haoyang Wu, Wenjie Wang, Lei Zhao
Abstract
The efficient energy transfer in La3GaGe5O16:Cr3+, Yb3+/Nd3+ and La3GaGe5O16:Cr3+, Yb3+, Nd3+ was investigated in detail. In this phosphor, Cr3+ acts as the energy absorber (250–700 nm) to sensitize Yb3+/Nd3+ in La3GaGe5O16. Under excitation at 418 nm, La3GaGe5O16:Cr3+, Yb3+ phosphors exhibited a broad emission band in the near-infrared (NIR) region located at 976 nm (La3GaGe5O16:Cr3+, Nd3+ at 1056 nm), which was attributed to the 2F5/2–2F7/2 transition of the Yb3+ ions (2F3/2 → 4I11/2 transition of Nd3+). Moreover, a Nd3+ ion was introduced into La3GaGe5O16:Cr3+, Yb3+. The analysis of excitation spectra and decay time proves that Nd3+ acts as a bridging ion in the system. This can be used as a new strategy to enhance the energy transfer in Cr3+, Yb3+ co-doped phosphors, and these phosphors have potential applications in NIR spectroscopy regulation.