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.