Near-infrared downconversion in Ce~(3+)-Yb~(3+) co-doped YAG

摘要

The phosphors YAG co-doped with Ce~(3+)-Yb~(3+) ion pair were successfully synthesized by solid state reaction method varying the concentration of Yb~(3+) ions from 1 to 15 % mol. The phosphors were characterized by powder X-ray powder diffraction and surface morphology was studied by scanning electronic microscope. The photolu-minescence (PL) properties were studied by spectropho-tometers in near infra red (NIR) and ultra violet visible region. The synthesized phosphors can convert a photon of blue region (469 nm) into photons of NIR region (979 and 992 nm). The co-operative energy transfer was studied by time decay curve and PL spectra. The theoretical value of quantum efficiency was calculated from steady time decay measurement and the maximum efficiency approached up to 145.19 %. Hence this phosphor could be used as a downconversion luminescent converter in front of crystalline silicon solar cell (c-Si) panels to reduce thermal-ization loss due to spectral mismatch of the solar cells.