Synthesis and optical properties of red/blue-emitting Sr 2MgSi 2O 7:Eu 3+/Eu 2+ phosphors for white LED

摘要

Phosphor-converted white light emitting diodes (white LEDs) have received great attention in recent years since they have several excellent features such as high lumen output, low power consumption, long lifetime and environmentally friendly. In this work, we report the co-precipitation synthesis of red/blue Sr2MgSi2O7:Eu3+/Eu2+phosphors with various Eu doping concentration. The results show that the obtained Sr2MgSi2O7:Eu3+/Eu2+phosphors have good crystallinity and emit strong red (Sr2MgSi2O7:Eu3+) and blue (Sr2MgSi2O7:Eu2+) emissions under near UV light excitation. The sharp emission peaks at 577, 590, 612, 653, and 701?nm corresponded to the typical5D0?→?7Fj(j?=?0,1,2,3,4) transitions of Eu3+, and the blue emission peaking at 460?nm is attributed to the typical 4f65d1-4f7transition of Eu2+in the same Sr2MgSi2O7host lattice. Both phosphors can be well excited in the wavelength range of 260–400?nm where the near UV-LED is well matched. The above results suggest that the Sr2MgSi2O7:Eu3+/Eu2+phosphors are promising red/blue-emitting phosphors for the application in near UV pumped phosphor-converted white LEDs.