Optical characteristics and energy transfer analysis of Dy3+-Pr3+ ions doped in CeF3 crystal

Abstract

The Dy,Pr:CeF3 single crystal was successfully grown and its optical characteristics were investigated systematically. The analysis of energy transfer process between Dy3+ and Pr3+ in CeF3 crystal was also carried out. The XRD study shows the crystal belongs to the hexagonal crystal system and its lattice parameters are a = 7.1252 Å and c = 7.2775 Å. The maximum phonon energy of the crystal was speculated to be 377.1 cm−1 by Raman spectrum. The absorption coefficient at 442 nm of Dy,Pr:CeF3 crystal is 0.89 cm−1. The radiative lifetime of Dy:4F9/2 level is 2.08 ms and the one of Pr:3P0 level is 145.25 μs in Dy,Pr:CeF3 crystal obtained by J-O theory calculation. The maximum emission cross-section of Dy: 4F9/2 → 6H13/2 transition is calculated to be ∼0.15 × 10−20 cm2 in the crystal. The fluorescence lifetimes of Dy:4F9/2, Pr:3P0 and Pr:1D2 levels are estimated to be ∼1.25 ms, ∼17.91 μs and ∼112.37 μs, respectively. The results show that Dy,Pr:CeF3 crystal not only owns a larger absorption coefficient at 442 nm than Dy:CeF3 crystal, but also holds the much longer lifetime of Pr:3P0 level than Pr:CeF3 crystal because of the energy transfer in Dy3+-Pr3+.