Radiation Induced Abnormal Reduction of Eu3+ and Luminescence Properties of NaLi2PO4:Eu (original) (raw)

Eu 3+ doped NaLi2PO4 sample synthesized via high temperature solid-state reaction exhibits the intense red emission under excitation to wavelength 318 nm light. In the photoluminescence (PL) emission spectra shown usual five emission peaks centered at around 580, 593, 618, 653, and 702 nm corresponding to the allowed transitions 5 D0→ 7 FJ (J = 0, 1, 2, 3, and 4) of Eu 3+ ion. The most prominent peaks were observed at 653 and 702 nm which increased the chromaticity quality followed dark red color with chromaticity coordinate (0.6298, 0.3589) and correlated color temperature (CCT) 1106 K. On exposing to γ-radiation, the red emission of Eu 3+ doped NaLi2PO4 phosphor diminished due to the reduction of Eu 3+ to Eu 2+ ions. The reduction of Eu 3+ → Eu 2+ was examined from the emission spectra of irradiated Eu 3+ doped NaLi2PO4 sample. Tuning the red emission of Eu 3+ doped NaLi2PO4 was observed and calculated the CIE (Commission Internationale de L'Eclairage) chromatic coordinates (chromatic coordinate (x, y), Correlated Color Temperature (CCT) and Duv etc.).