VUV-blue photon conversion by cross-relaxation in KY3F10:Tm3+, Ce3+

Efficient conversion of VUV photons into blue photons has a great interest for plasma display and free-mercury lamps. A cross relaxation energy transfer scheme using the 5d states of Tm3+ and Ce3+ is proposed and tested in the host KY3F10. Emission spectra along with studies of the time evolution under UV and VUV excitation are reported and analyzed. The results show that the proposed quantum cutting mechanism occurs and is more efficient than in single Tm3+ doped KY3F10.