A novel green-emitting phosphor Ba2Gd2Si4O13:Eu2+ for near UV-pumped light-emitting diodes

Abstract

A novel green-emitting phosphor Ba₂Gd₂Si₄O₁₃:Eu²⁺ has been prepared using a conventional high-temperature solid-state method. X-ray diffraction and photoluminescence spectra were used to characterize the as-synthesized phosphor. The Ba₂Gd₂Si₄O₁₃:Eu²⁺ phosphor exhibits a broad emission band centered at 503 nm under 365 nm excitation. Monitoring the 503 nm emission, the Ba₂Gd₂Si₄O₁₃:Eu²⁺ phosphor shows an intense broad excitation band ranging from 200 to 410 nm. The concentration quenching mechanism has been investigated, and demonstrated to involve a dipole–dipole interaction. The critical concentration was found to be about 4 mol%. The critical distance calculated using the concentration method and spectral overlap method was 23.9 Å and 27.1 Å, respectively. The temperature-dependent photoluminescence and CIE chromaticity coordinate of the Ba₂Gd₂Si₄O₁₃:Eu²⁺ phosphor were also investigated in this work. The results revealed that Ba₂Gd₂Si₄O₁₃:Eu²⁺ possesses excellent thermal stability and the CIE value of the Ba₂Gd₂Si₄O₁₃:0.04 Eu²⁺ phosphor upon 365 nm excitation is (0.211, 0.434), located in the green region. All the properties indicate that the Ba₂Gd₂Si₄O₁₃:Eu²⁺ phosphor is a potential green-emitting phosphor fit for ultraviolet light pumped LEDs.