Luminescent properties and energy transfer of Sr3La(PO4)3:Sm3+, Eu3+ for white LEDs

Abstract

Abstract A series of Sm3+, Eu3+, and Sm3+–Eu3+ doped Sr3La(PO4)3 (SLP) are synthesized by using a high temperature solid-state method. SLP:Eu3+ emits red light, and the strongest peak locates at 613 nm under the 392 nm radiation excitation, which is attributed to the 5D0 → 7F2 transition of Eu3+. SLP:Sm3+ produces red-orange light, and the peak locates at 598 nm under the 400 nm radiation excitation, which is assigned to the 4G5/2 → 6H7/2 transition of Sm3+. The energy transfer from Sm3+ to Eu3+ in SLP has been validated and the critical distance (Rc) of Sm3+ to Eu3+ in SLP is calculated to be 1.50 nm. With increasing the Eu3+ doped concentration, the energy transfer efficiency (Sm3+ → Eu3+) gradually increases to 59.6%. Moreover, the emission color and emission intensity of SLP:Sm3+, Eu3+ can be tuned by properly tuning the relative doped composition of Sm3+–Eu3+.