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Near Infrared Quantum Cutting for Solar Cells in CeF3:Yb3+ Nanophosphors

The CeF3 nanophosphors with Yb3+ concentrations from 0 to 8% had been prepared by hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Their photoluminescence properties including excitation spectra, Uv-visibe and near infrared (NIR) emission spectra and fluorescence dynamics were studied. In the CeF3: Yb3+ nanophosphors an intensity infrared emission originated from Yb3+2F5/2 - 2F7/2 transition at 900-1050 nm matching to the energy of Si band gap of Si-based solar cells was observed under the excitation of 5d level of Ce3+. The lifetime of Ce3+ decreases and the quantum efficiency (QE) increases with increasing Yb3+ concentration.