Spectral characteristics and luminescence applications of Eu3+-activated fluorosilicate Na2MgGd2[SiO3]4F2

• A novel Eu 3+ -activated fluorosilicate Na 2 MgGd 2 [SiO 3 ] 4 F 2 was firstly developed. • Unique structural characteristics make it have excellent application performance. • Quantum Efficiency (QE) of 57 % was achieved in Na 2 MgGd 2-2 x Eu 2 x [SiO 3 ] 4 F 2 ( x = 0.25). • The application performance of the phosphor in lighting devices is reported. This work reports the luminescence spectra and application of novel Eu 3+ -doped Na 2 MgGd 2 [SiO 3 ] 4 F 2 phosphor. The X-ray powder diffraction confirmed the pure phase formation of the samples with the monoclinic space group P 2 1 /c (No:14). The phosphors demonstrated efficient red emission at 613 nm from the electric dipole transitions 5 D 0 → 7 F 2 . The optimal doping concentration was found to be approximately 25 mol%. Na 2 MgGd 2 [SiO 3 ] 4 F 2 :0.25Eu 3+ exhibits a high quantum efficiency (QE) of 57 % with excellent thermal stability and pure chromaticity. Red- and the white light-emitting diode devices were packaged using InGaN chips and Na 2 MgGd 2 [SiO 3 ] 4 F 2 :0.25Eu 3+ . The fabricated WLED has CIE coordinates of ( x = 0.33, y = 0.34), which are very close to the white point in the National Television System Committee ( x = 0.33, y = 0.33). The color rendering index (CRI, Ra) and correlated color temperature (CCT) of the WLED are 91 and 4400 K, respectively. The results show that as a red luminescent phosphor, it is a potential candidate for the preparation of near-UV/blue InGaN-based WLEDs.