Photoluminescence enhancement in Na3SO4Cl:X (X = Ce3+, Eu3+ or Dy3+) material.

The compound Na3SO4Cl X (X = Ce(3+), Eu(3+) or Dy(3+)) prepared by the wet chemical method was studied for its photoluminescence (PL) and energy transfer characteristics. The PL from Na3 SO4 Cl:Ce(3+) shows strong emission at 322 nm at an excitation of 272 nm. Therefore, an efficient Ce(3+) → Dy(3+), Eu(2+) → Dy(3+) and Eu(2+) → Eu(3+) energy transfer had taken place in this host. The Dy(3+) emission caused by Ce(3+) → Dy(3+) energy transfer under ultraviolet (UV) wavelengths peaked at around 477 nm and 572 nm due to (4) F9/2 → (6) H15/2 and (6) H13/2 transitions with yellow-orange emission in the Na3 SO4 Cl lattice. An intense Dy(3+) emission was observed at 482 and 576 nm caused by the Eu(2+) → Dy(3+) energy transfer process and due to (4) F9/2 → (6) H15/2 and (4) F9/2 → (6) H13/2 transitions respectively. The Eu(3+) blue to red light emission caused by the Eu(2+) → Eu(3+) energy transfer peaked at 593 nm and 617 nm due to (5) D0 → (5) D3 transitions. The presence of trivalent Eu in Na3 SO4 Cl suggested the presence of Eu(3+) in the host compound that occupied two different lattice sites and that peaked at 593 and 617 nm due to (5) D0 → (7) F1 and (5) D0 → (7) F2 transitions respectively. The trivalent europium ion is very useful for studying the nature of metal coordination in various systems due to its non-degenerate emitting (5) D0 state. The present paper discusses the photoluminescence characteristics of Eu(2+) → Dy(3+) and Eu(2+) → Eu(3+) energy transfer. This compound may be useful as a lamp phosphor.