Resonant energy transfer and near-infrared emission enhanced by tri-doped Sr 2 SiO 4 : Ce 3+ , Tb 3+ , Yb 3+ phosphors for silicon solar cells

Abstract A novel tri-doped Sr 2 SiO 4 : Ce 3+ , Tb 3+ , Yb 3+ phosphor was prepared using a conventional solid reaction. The resonant energy transfer (ET) with Ce 3+ → Tb 3+ through electric dipole-dipole interactions was demonstrated with luminescent spectra and decay lifetime curves. Upon UV photon excitation at 372 nm of Tb 3+ ions and 350 nm of Ce 3+ ions, Yb 3+ emissions were detected in the near-infrared (NIR) region with a main peak at 977 nm, which belonged to the 2 F 5/2 → 2 F 7/2 transition and corresponding perfectly with silicon solar cell maximum spectral responses. The NIR emission intensity of Sr 2 SiO 4 : Ce 3+ , Tb 3+ , Yb 3+ was almost 125 times greater than that of Sr 2 SiO 4 : Yb 3+ , which demonstrated that the 4 f –5 d luminescence of Ce 3+ could be used to sensitize the Tb 3+ –Yb 3+ down-conversion process. This tri-doped Ce 3+ −Tb 3+ −Yb 3+ system offered potential applications for NIR down-conversion phosphors for silicon solar cells.