Synthesis, structural and spectroscopic studies in Sr ₃ (PO ₄ ) ₂ :Eu ²⁺ , Eu ³⁺ phosphors for opto-electronic applications

A series of Sr3(PO4)2 phosphor activated by Eu3+, Eu2+ was obtained via a solid-state metathesis process using domestic microwave oven. Afterwards, the prepared phosphor was reduced using the charcoal environment at 850 °C for 1 hr to achieve Eu2+ -doped phosphor. The structural characteristics were examined through X-ray diffraction, which confirmed that the prepared compounds crystallize in a stable cubic system with well-defined lattice parameters, reflecting structural stability. The photoluminescence plot of Sr3(PO4)2: Eu2+ reflects intense blue color emission at 403 nm due to (4f6 5d1) → 8S7/2 transition of Eu2+ doping. The emission spectra of Sr3(PO4)2: Eu3+ contain multiple peaks following 5D0→7FJ (J = 1, 2, 3, 4, 5, 6) transitions, at various wavelengths 580 nm, 591 nm, 614 nm and 621 nm attribute to 5D0→7F1,5D0→7F2,5D0→7F3 and 5D0→7F4 transitions respectively. The estimated lifetime of Sr3(PO4)2: 2%Eu3+ and Sr3(PO4)2: 0.25%Eu2+ compounds recorded as 2.9742 and 5.3617 ms, respectively. The calculated CCT value of Sr3(PO4)2: Eu2+ and Sr3(PO4)2: Eu3+ phosphors were estimated to be 1820.11 K and 2060.48 K, also the color purity was calculated as 42.02% and 95.4% respectively. The Eu3+/Eu2+-doped Sr3(PO4)2 phosphors have been proposed to be potential candidates for w-LED, blue and red emitting devices for wLED as well as Anti-counterfeiting and biological imaging.