Site Selective Excitation and Energy Transfer in LiKGdF_5 Crystal Co-doped with Er~(3+) and Tb~(3+)

摘要

Crystals of LiKGdF_5: Er~(3+), Tb~(3+) grown by the hydrothermal synthesis technique with concentrations of 2 percent and 0.4 percent were analysed. By using site selective excitation measured at low temperature, luminescence and excitation spectra from Er~(3+) and Tb~(3+) ions embedded in LiKGdF_5 were clearly separated . The lifetimes of the emitting levels ~4S_(3/2) of Er~(3+) and ~5D_4 of Tb~(3+) were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb~(3+) to Er~(3+) in the crystal was then investigated via transient experiments