Visible to near infrared conversion in Ce3+-Yb3+ Co-doped YAG ceramics

In Ce3+-Yb3+ co-doped Y3Al5O12 (YAG) ceramics, possibility of quantum cutting mechanism converting one visible photon into two NIR photons with optimum quantum efficiency approaching 200% have been investigated. In this material, Yb3+ emissions due to the F-2(5/2)-F-2(7/2) in the range of 1 mu m were observed upon the excitation of 5d level of Ce3+. In addition, excitation spectra of Yb3+ emission corresponded to that of Ce3+ emission completely. Lifetime of the 5d level of Ce3+ decreased with increasing Yb3+ content. These result's indicate the energy transfer (ET) from the 5d levels of Ce3+ to the F-5(5/2) level of Yb3+. In (Y0.945Ce0.005Yb0.05) 3Al5O12 sample, the directly measured quantum yield (QY) of Yb3+ emission upon the excitation of 5d level of Ce3+ was about 12% and lower than QY (96%) that estimated from the ET efficiency which was calculated with the measured lifetime of Ce3+. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3194310]