Dual photoluminescence emission of Er~(3+), Yb~(3+) and Er~(3+)/Yb~(3+) doped La_3Ga_(5.5)Nb_(0.5)O_(14) ceramics under UV and IR excitation

摘要

Synthesis of pure and Yb3+, Er3+ and Er3+/Yb3+ doped La3Ga5.5Nb0.5O14 (LGN) ceramics by solid state reaction method and their photoluminescence characteristics are presented. Er3+ and Er3+/Yb(3+)doped LGN ceramics emit green light at 523 (H-2(11/2) -> I-4(15/2)) and 551 (S-4(3/2) -> I-4(15/2)) nm through down conversion upon UV excitation. Er3+/Yb3+-doped LGN ceramics also act as upconvertors, by transforming infrared excitation (973 nm) into UV light ((4)G(11/2) -> I-4(15/2)) which is due to three-photo energy transfer process. The emission characteristics confirm that LGN is a superior host material for both up and down conversions and hence it can be used for light emitting devices and biological applications. The effects of Er3+ and Yb3+ doping on the structure, morphology of the prepared ceramics were also studied and discussed.