Fluorescence and crystal structure of SrLa_1-x AlO₄ :xEu³⁺ phosphor synthesized using a sol-gel method

The SrLa_1-x AlO₄ :xEu³⁺ phosphors were obtained using one calcination of a precursor synthesized using a sol-gel method. When excited at 396 nm, this phosphor emits a red light mixed with several strong peaks centred at 596 nm, 616 nm and 625 nm, attributed to ⁵ D₀ →⁷ F_{1, 2} transitions of Eu³⁺ ions, respectively. The concentration quenching occurs at x = 1.5 mol% mol of SrLa_1-x Eu_x AlO₄ and the critical energy transfer distance is calculated to be 13.13 Å, the dipole-dipole interaction was found to play a role. In addition, the colour purity could be up to 97.5%. Simultaneously, the thermal stability of SrLaAlO₄ :Eu³⁺ was measured and the thermal quenching was found at c. 275°C (T_0.5 ), the excitation energy was 0.19 eV. Current results demonstrate that SrLaAlO₄ :Eu³⁺ could be a red component candidate for white light LEDs pumped by near-UV chips.