Document Type : Research Article

Authors

• S.P. Puppalwar
• M.S. Mendhe
• S.J. Dhoble

Abstract

Tb ³⁺ /Sm ³⁺ single as well as co-doped LaMgAl₁₁O₁₉ (LMA) phosphors have been synthesized by a low-temperature solution combustion method. The X-ray diffraction pattern, photoluminescence properties and energy transfer (ET) processes between rare earth (RE) ions, were investigated in detail. The mechanism of energy transfer (ET) from Tb³⁺ to Sm³⁺ was seen as the dipole–dipole interaction. Efficient ET from Tb³⁺ to Sm³⁺ ions was observed, leading to color-tunable emissions of LMA:0.02Tb³⁺ , x Sm 3+ (x = 0.005 to 0.02 mol) phosphors. The efficiency of the ET gradually increased with increase in the Sm 3+ ion concentration, reaching a maximum of 78.28% at Tb³⁺ ion concentration 0.02mol. The critical distance (Rc) among sensitizer and activator by the concentration quenching method was estimated to be 27.96 Å. The LMA: Tb³⁺ , Sm³⁺ phosphors exhibited the emission peaks in the blue ( ⁵D₃→ ⁷FJ = _{5, 4, 3, and 2}), green ( ⁵D₄→ ⁷FJ = _{6, 5, and 4}), and orange-red ( ⁴G_5/2→ ⁶HJ = _{5/2, 7/2, and 9/2}) regions under the excitation wavelength of 375 nm. As a consequence of fine-tuning of the emission composition of the Tb³⁺ and Sm³⁺ ions, multicolor emitting luminescence properties can be achieved in a single host lattice LMA.

Graphical Abstract

Keywords

• LaMgAl11O19
• luminescence
• energy transfer
• dipole
• dipole interaction
• concentration quenching