PREDICTABILITY OF QUANTUM SPLITTING IN Pr~(3+) ACTIVATED PDP-PHOSPHORS

摘要

Luminescence quantum efficiency larger than unity is in principle possible utilizing a cascade emission starting from the ~1S_0 level of Pr~(3+). This 4f~2-level is located near 47,000 cm~(-1) above the ground state and may decay under emission of a ≈385 nm photon to one of the ~3P_J levels. The second step in the cascade starts e.g. from the ~3P_0 level and ends at the ~3H_4 ground state under emission of a ≈480 nm photon. One very stringent requirement for this cascade to occur is that the lowest level of the 4f5d configuration must be located well above the ~1S_0 level. However, for the fast majority of compounds this is not the case. To find suitable host crystals, one needs to understand the relationship between 5d-level energy and type of host crystal. Recently, one of us collected and analyzed a fast amount of data on the energy of the lowest level of the 4f~(n-1)5d configuration of trivalent lanthanides in inorganic materials. In this work these results will be exploited to predict the quantum splitting phenomenon of Pr~(3+) in inorganic materials.