Mechanoluminescence and photoluminescence properties of Eu³⁺ -activated SrGa₂ O₄ phosphors

Red-emitting Eu³⁺ activated SrGa₂ O₄ phosphors were synthesized using a conventional solid-state reaction method. The structural, optical, and luminescence properties were systematically investigated. The synthesized phosphors are single phase with a monoclinic structure. There are no significant changes in the phase and the crystal structure of the host matrix after incorporating Eu³⁺ ions. The undoped and Eu³⁺ doped SrGa₂ O₄ phosphors exhibited good mechanoluminescence (ML) emission without any irradiation with ultraviolet (UV) or gamma rays. Eu³⁺ -activated SrGa₂ O₄ phosphors have prominent red emission attributed to ⁵ D₀  → ⁷ F₂ forced electric dipole transition excited at 395 nm. The colour coordinates and purity of the SrGa₂ O₄ : 0.08 Eu³⁺ phosphor were calculated to be (0.6102, 0.3810) and 97.6%, respectively. The quantum efficiency is 12.68%, and was better than that of commercially available red phosphors. The ML and photoluminescence studies revealed that the synthesized phosphors can act as potential candidates for stress sensors, UV or near-UV light-emitting diodes (NUV LEDs) and components of phosphor-converted white light-emitting diode (pc-WLED) applications.