Luminescence properties of CaAlSiN3:Eu2+ phosphor prepared by direct-nitriding method using fine metal hydride powders

Ammonothermal Synthesis of Novel Nitrides: Case Study on CaGaSiN3

“…Similar values are observed in comparable nitrides: Typical Si−N and Ga−N bond lengths range from 1.60 to 1.80 Å in nitridosilicates and from 1.92 to 2.06 Å in nitridogallates, respectively . The Ca−N distances in CaAlSiN 3 :Eu 2+ are between 2.32 and 2.69 Å, and on average slightly shorter than in CaGaSiN 3 :Eu 2+ . The Ca−Ca distances amount to 3.31 Å and are therefore similar to those in other calcium nitridosilicates like CaSiN 2 (3.05–3.30 Å) and CaAlSiN 3 (3.27 Å) …”

“…The reflections were indexed with an orthorhombic unit cell; systematic absences indicated the space group Cmc 2 1 . Wyckoff positions and coordinates of isotypic CaAlSiN 3 were taken as starting values for the Rietveld refinement . Displacement parameters and occupancy factors could not be refined to reasonable values because of crystallite size broadening and overlapping of reflections in the X‐ray diffraction pattern.…”

The Enhanced Red Emission and Improved Thermal Stability of CaAlSiN3:Eu2+ Phosphors by Using Nano-EuB6 as Raw Material

“…The above result is also consistent with the ratios of N/O in different samples that measured by EDS (see Table 1). For the impurity phase AlN, its precise stoichiometric ratio in the reaction can hardly be determined due to its low solubility in CaAlSiN 3 , which results in the redundant AlN [32,33]. It can be found from Figure 3 that the main diffraction peaks of CaAlSiN 3 in the range of 30–40° shift to a low degree with the increase of Eu 2+ ion concentration in CASN:Eu 2+ @EuB 6 , which could be ascribed to be the substitution of larger B 2− (1.40 Å, CN = 4) for smaller N 3− (1.32 Å, CN = 4) [17].…”

“…Therefore, we believe that according to the above schematic pattern the length of the Eu–B bonds is longer than that of the Eu–N bonds (see Figure 6e,f). In addition, the metal cation ratio in CaAlSiN 3 is Ca:Al:Si = 1:1:1, in which Ca and Al/Si occupied on the 4a and 8b sites in the space group of Ccm2 1 , respectively [25,32]. In the series of CASN:Eu 2+ @EuB 6 , the decrease of oxygen content can prevent the formation of Ca 2 SiO 4 and increase the content of occupation Ca ions, which can also lead to the improvement of emission intensity.…”

Li6Sr(La1−xEux)2Sb2O12(0<x≤1.0) solid-solution red phosphors for white light-emitting diodes

“…In order to solve such problem, another approach is proposed by combining the red/green/blue tri-color phosphors with the near-ultraviolet (n-UV) chip peaking at 370-410 nm or conjunction with green and red phosphors by using blue chip, which can offer higher CRI and excellent color uniformity [1,7]. However, the current commercial red phosphors are mainly sulfides and nitrides such as Y 2 O 2 S:Eu 3 þ [8], CaAlSiN 3 :Eu 2 þ [9], and Ba 2 Si 5 N 8 : Eu 2 þ [10], which still limited their applications extensively due to the chemical instability and rigorous synthetic routes. Therefore, it is highly urgent and desirable to develop novel and stable red phosphors.…”