Preparation, characterization and luminescence properties of porous Si3N4 ceramics with Eu2O3 as sintering additive

Simplified Synthesis and Luminous Mechanism of Eu²⁺-Doped α-Si₃N₄ Nanowires with Strong Green Luminescent Properties

“…4 (b)), three energy peaks can be obviously detected. According to previous studies, the bonding energies of 1164.91 and 1133.41 eV are attributed to the Eu 3+ in Eu 2 O 3 and the peak located at 1153.91 eV is consistent well with the Eu 2+ [14]. To observe transformation of valence in Eu ion during the nitridation process, the Eu 3d core-orbit spectrum of Eu-doped nanocrystalline Si powder is characterized as shown in Fig.…”

“…The as-synthesized Eu 2+ -doped Si 3 N 4 nanowires emitted strong yellow light, which is related to the transition from 4f 6 5d to 4f 7 in Eu 2+ . Yu [14] prepared porous Si 3 N 4 ceramics with Eu 2 O 3 as sintering additive and discussed the different luminescence of Eu 2+ and Eu 3+ . The previous studies suggest that the broad band emission of Eu-doped Si 3 N 4 is mainly attributed to the divalent europium.…”

A novel polymer-derived method to prepare Eu-doped Si3N4 yellow phosphor

“…1(b). The smaller particle-like nanocrystallites (circled) were formed initially, which is characteristic of α-Si 3 N 4 , while the apparent equiaxial and rod-like nanocrystallites forming β-Si 3 N 4 were the result of anisotropic growth along the low energy (100) planes [3]. The excitation and emission spectra, as well as the photoluminescence (PL) decay curves of Si 3 N 4 :Eu are shown in Fig.…”

“…Among them, Eu-doped nitridosilicate phosphors such as the redemitting M 2 Si 2 N 8 :Eu 2 þ (M¼ Ca, Sr, Ba) [1,2] and yellowemitting Si 3 N 4 (α and β):Eu 2 þ [3], blue-emitting α-Si 3 N 4 :Eu 2 þ [4], and green-emitting β-sialon:Eu 2 þ [5] have shown great prospects with a broad excitation and emission in UV-Visible spectral region. However, the conventional methods to prepare Eu-doped nitridosilicate phosphors commonly start from Eu nitrides/oxides and silicon nitrides as raw materials.…”

“…For instance, the doping from Eu nitrides required the reaction of Eu(NH 2 ) 2 obtained by dissolution of Eu in supercritical ammonia (NH 3 ) at 150 1C and 300 bar pressure with Si(NH) 2 precursor prepared separately [1]. In the case of doping from Eu oxides, the mixture of Eu 2 O 3 and α-Si 3 N 4 powders was wet milled with high purity Si 3 N 4 balls in anhydrous ethanol for 12 h [3] or the mixed powders were placed into a BN crucible and fired at 1600 1C for 5 h under N 2 -H 2 (5%) atmosphere [4]. The low efficient Eu doping by a solid-state reaction also made the preparation method very complex.…”