An efficient near-infrared (NIR) quantum cutting (QC) Tb3+ and Yb3+ co-doped phosphor Sr3Gd(PO4)3 has been synthesized by conventional high temperature solid technique. Upon excitation of Tb3+ with a visible photon at 485 nm, two NIR photons could be emitted by Yb3+ through cooperative energy transfer (CTE) from Tb3+ to two Yb3+ ions. Excitation and emission spectra as well as fluorescence decay measurements have been carried out to examine the occurrence of cooperative energy transfer (CET ) from Tb3+ to Yb3+ ions. The result indicates Tb3+ and Yb3+ co-doped Sr3Gd(PO4)3 is potentially used as down-converter layer in silicon-based solar cell.
