Novel SrGd₂Al₂O₇:Mn⁴⁺, Nd³⁺, and Yb³⁺ phosphors for c-Si solar cells

Novel single-doped and codoped SrGd₂Al₂O₇-based (SGA) phosphors with tunable emission were synthesized via the solid-state reaction approach. The optimal SGA:0.0008Mn⁴⁺ phosphor presents an emission band peaking at 709 nm and shows great red luminescence properties. With the incorporation of Nd³⁺/Yb³⁺ into SGA:0.0008Mn⁴⁺, an efficient energy transfer Mn⁴⁺→ Nd³⁺/Yb³⁺ was observed. When Nd³⁺ and Yb³⁺ were codoped into SGA:0.0008Mn⁴⁺, an energy transfer mechanism from Mn⁴⁺ to Nd³⁺ to Yb³⁺ was found on the basis of the energy transfer mediation of Nd³⁺ connecting the Mn⁴⁺ and Yb³⁺ luminescent centers. It results in a strong near-infrared emission in the spectral region of high response of c-Si solar cells, which suggests a potential approach to improve the energy conversion efficiency of c-Si solar cells. The findings offer a novel route to design new down-conversion luminescent materials for the c-Si solar cells.