Wydział Chemii

Małgorzata Puchalska

Eugeniusz Zych

2017

Optical Materials

74

2-11

10.1016/j.optmat.2017.05.060

Naukowa

Angielski

Artykuł

Ce³⁺ doped and Ce³⁺,Mn²⁺ co-doped calcium aluminoborate (CAB) phosphors were synthesised by solid-state reaction method and their optical properties were studied. X-ray powder diffraction, SEM and TEM studies indicated the crystallization of the main trigonal CaAl₂B₂O₇ phase and the presence of an additional non-crystalline phase. It was also observed that increasing dopant concentration promotes phase separation. Hence, both series of phosphors demonstrated the changes in luminescence properties via activator concentration variation. Upon UV excitation (λ_ex = 310 nm) Ce³⁺ doped and Ce³⁺,Mn²⁺ co-doped materials yielded intensive blue and pinkish luminescence, respectively. The spectra of CAB:Ce³⁺ samples showed a broad emission band due to 5d→4f transition of Ce³⁺, which broadened and shifted to longer wavelengths with increasing dopant content. Mn²⁺co-doping caused appearance of another broad-band emission with a maximum of 680 nm, resulting from the ⁴T₁(⁴G) →⁶A₁(⁶S) transition of Mn²⁺. Detailed analysis of the emission and excitation spectra as well as decay time traces as a function of dopant concentration showed that efficient resonant energy transfer mainly occurs between Ce³⁺ and Mn²⁺incorporated in the non-crystalline phase in CAB material. The estimated values of energy transfer efficiency of CAB:Ce³⁺(3%),Mn²⁺(4%) is close to 52%.

Calcium aluminoborate, energy transfer, Ce3+ luminescence, Mn2+ luminescence, phase separation

https://doi.org/10.1016/j.optmat.2017.05.060

http://www.elsevier.com