Novel NIR LaGaO:Cr,Ln (Ln = Yb, Nd, Er) phosphors via energy transfer for C-Si-based solar cells.

A series of Cr-Yb/Nd/Er codoped LaGaO phosphors were synthesized by a traditional solid-state method. The morphology, crystal structure, phase purity, and the luminescence properties of samples were characterized by using X-ray diffraction, Rietveld refinement, field-emission scanning electron microscopy, and photoluminescence. The obtained phosphors exhibit efficient broad absorption in the near ultraviolet and visible (UV-Vis) region and intense near infrared (NIR) emission, due to the energy transfer process from the Cr to Yb/Nd/Er ions, which match well with the maximum photon flux region of the solar spectrum and the optimal spectral response of the C-Si solar cell. Moreover, we also observed an energy transfer from the Nd/Er to Yb ions. The efficiency was investigated and analyzed by the visible and NIR emission spectra and lifetime decay curve and the energy transfer efficiency was as high as 77%. Our results reveal that the Cr-Yb/Nd/Er codoped phosphors are promising materials for enhancing the efficiency of solar cells.