Efficient conversion from UV light to near-IR emission in Yb³⁺-doped triple-layered perovskite CaLaNb₃O₁₀

Yb³⁺-doped triple-layered perovskite CaLaNb₃O₁₀ micro-particles were synthesized via the solid-state reaction method. The crystal structure and morphology of the polycrystalline samples were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. The reflectance spectra, photoluminescence (PL) excitation and emission spectra, the decay curves, and the absolute quantum efficiency (QE) of the near-infrared (NIR) emission (910-1100 nm) were measured. Under excitation of UV light, Yb³⁺-doped perovskite shows an intense NIR emission attributed to the ²F_5/2 → ²F_7/2 transitions of Yb³⁺ ions, which could match maximum spectral response of a Si-based solar cell. This is beneficial for its possible application in an enhancement of the photovoltaic conversion efficiency of solar energy utilization. The efficient energy transfer in Yb³⁺-doped CaLaNb₃O₁₀ from NbO₆ groups into Yb³⁺ ions was confirmed by the spectra and fluorescent decay measurements. Cooperative energy transfer (CET) was supposed to be the NIR emission mechanism.