Photoluminescence of Eu2+, Ce3+ and Tb3+ in a new potassium barium phosphate K2Ba3(P2O7)2 host lattice.

The Eu 2+ , Ce 3+ , Tb 3+ and Ce 3+ -Tb 3+ doped ternary metal diphosphate K 2 Ba 3 (P 2 O 7 ) 2 is prepared using high temperature solid state synthesis. K 2 Ba 3 (P 2 O 7 ) 2 :Eu 2+ shows a deep blue emission ( λ max = 405 nm) when it is excited by UV lights. The broad peak at 405 nm can be decomposed to two Gaussian curves with maxima at 405 and 440 nm which can be attributed to the presence of two crystallographically different Eu 2+ sites in the crystal structure. The emission spectrum of K 2 Ba 3 (P 2 O 7 ) 2 :Ce 3+ is dependent of the excitation wavelength that also results from the two crystallographically different Ce 3+ sites. The emission spectrum of K 2 Ba 3 (P 2 O 7 ) 2 :Tb 3+ shows the 5 D 3 and 5 D 4 emission lines. The f-d spin-allowed and spin-forbidden transitions in Tb 3+ in K 2 Ba 3 (P 2 O 7 ) 2 are at about 225 and 250 nm, respectively. For the (Ce 3+ , Tb 3+ ) co-doped K 2 Ba 3 (P 2 O 7 ) 2 system, the energy transfer from Ce 3+ to Tb 3+ is observed. [ABSTRACT FROM AUTHOR]