Application of NaYF4:Er3+ up-converting phosphors for enhanced near-infrared silicon solar cell response

Abstract

Erbium-doped sodium yttrium fluoride $({\mathrm{NaYF}}_4:{\mathrm{Er}}^{3+})$ up-conversion phosphors were attached to the rear of a bifacial silicon solar cell to enhance its reponsivity in the near-infrared. The incident wavelength and light intensity were varied and the resulting short circuit current of the solar cell was measured. A close match between the spectral features of the external quantum efficiency and the phosphor absorption is consistent with the energy transfer up-conversion process. The peak external quantum efficiency of the silicon solar cell was measured to be $(2.5\pm 0.2)\%$ under 5.1 mW laser excitation at 1523 nm, corresponding to an internal quantum efficiency of 3.8%.