Preparation and photoluminescence properties of high thermal stability Sr 3 Ga 2 Sn 1 . 5 Si 2 . 5 O 14 :Eu 3+ red phosphors for high-power light-emitting diodes application

A series of Sr 3 Ga 2 Sn 1 · 5 Si 2 · 5 O 14 : x Eu 3+ (SGSSO: x Eu 3+ ) phosphors with excellent thermal stability were prepared by the solid-state reaction method. The phase and luminescence properties of the sample were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance spectroscopy, and photoluminescence (PL) spectra. Under the excitation of 395 nm, the SGSSO:Eu 3+ phosphor exhibits strong red emission at 618 nm, which is attributed to the 5 D 0 → 7 F 2 transition of the Eu 3+ ions. When monitoring the 618 nm emission peak, the excitation spectrum contains several excitation peaks with a maximum value of 395 nm, which is well matched with the commercial violet LED chips. In addition, the emission spectra of SGSSO:Eu 3+ at different temperatures have also been studied. Pleasantly, the luminous intensity of the SGSSO:Eu 3+ sample at 150 °C still maintains 80.2% of that at room temperature, demonstrating its good thermal stability and application potential in high-power LEDs. The mechanism for the high thermal stability of the as-prepared phosphor was also discussed. Moreover, the photoluminescence quantum yield of the optimized SGSSO:0.06Eu 3+ phosphor can reach 62.7%. Finally, a warm white LED device with high color rendering index and low color temperature was prepared using the prepared SGSSO:Eu 3+ phosphor as a red component, verifying the application potential of SGSSO:0.06Eu 3+ in LEDs.