Visible quantum cutting in BaF2:Gd,Eu via downconversion

The visible quantum cutting in BaF2:Gd,Eu via Downconversion has been observed. In the quantum cutting process, one VUV photon absorbed by Gd3+ can be split into two visible photons emitting by Eu3+ through cross-relaxation between Gd3+ and Eu3+. According to the calculation from the emission spectra under different wavelength excitation, we can obtain the two-step energy transfer process with a visible quantum efficiency up to 194%.