Host sensitized near-infrared emission in Nd³⁺-Yb³⁺ Co-doped Na₂GdMg₂V₃O₁₂ phosphor

Yb³⁺/Nd³⁺ singly and co-doped Na₂GdMg₂V₃O₁₂ phosphors with near-infrared (NIR) emission were synthesized via sol-gel method. The phase purity and structure of samples were characterized by X-ray diffraction (XRD), the photoluminescence emission (PL) and excitation (PLE) spectra along with decay curves were also measured. Near infrared (NIR) emissions (850–1150 nm) from acceptors Yb³⁺ or Nd³⁺ matching well with the response curve of the silicon solar cell were obtained, in which VO₄ ³⁻ groups acted as sensitizers by capturing near ultraviolet photons which are not absorbed efficiently by silicon solar cell and transferred them to Yb³⁺/Nd³⁺ by energy transfer processes. The NIR emission intensities of the Nd³⁺-Yb³⁺co-doped samples Na₂GdMg₂V₃O₁₂ were enhanced greatly in comparison with that of Nd³⁺/Yb³⁺ singly doped samples, and the possible energy transfer processes were also discussed in detail. Results indicate that the obtained samples are potential solar spectral down-conversion (DC) convertors to enhance the conversion efficiency of the silicon solar cells.