Carbothermal Reduction Synthesis Using CaCN2 as Calcium and Carbon Sources for CaAlSiN3:Eu2+ Phosphor and Their Luminescence Properties

Abstract

High-quality powders of mixed metal nitride phosphor, CaAlSiN 3 :Eu 2+ , were successfully synthesized using only inexpensive and air-stable materials, viz. CaCN 2 , CaCO 3 :Eu 3+ , AlN, and Si 3 N 4 , with no impurities such as AlN or carbon residue by a CRN method even under conditions of normal N 2 pressure (0.1 MPa) and a moderate temperature of 1600°C for 57 h. The resultant phosphors were well crystallized and gave an intense red emission band peaking at about 650 nm by optimizing the dopant amount of Eu 2+ ion (ca. 3 atom %).Metal nitride phosphors such as M 2 Si 5 N 8 :Eu 2+ (M = Ca, Sr, and Ba) and M¤AlSiN 3 :Eu 2+ (M¤ = Ca and Sr) have been used as key materials for high color-rendering solid illumination parts based on blue-emitting InGaN chips as the red color component source. This is because the 5d energy level for the excited state of Eu 2+ ion is effectively lowered by the nephelauxetic effect of the covalent EuN bonding, and thus the 4f electron of Eu 2+ ion is excited to the 5d energy level even by the blue light of an LED chip.

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

“…Oxygen contents of the CaAlSiN 3 :Eu 2+ phosphors prepared from the (Ca,Eu)AlSi and (Ca,Eu)AlSiH x powders were 4.21 and 3.07 wt% (see Table 3, samples a and b) that were extremely high compare with the value of the CaAlSiN 3 :Eu 2+ phosphor synthesized by the CRN method using CaCN 2 as one raw material for reducing CaCO 3 to Ca 3 N 2 , CaCN 2 + CaCO 3 ? 2/3Ca 3 N 2 + CO 2 + CO + 1/2N 2 [28]. However, it is noted that, for the CaAlSiN 3 :Eu 2+ phosphor (sample b), the oxygen content is relatively low and thus, the emission intensity is higher than that of the sample (a).…”

Carbothermal synthesis of CaAlSiN3:Eu2+ red-emitting phosphors and the photoluminescent properties

“…At present, there are few reports about the synthesis of CaAlSiN 3 :Eu 2? phosphors through carbothermal method except for the research by Kim et al [23] with hazardous CaCN 2 as calcium and carbon sources. Very recently, Li et al [24] reported the carbothermal synthesis of CaAlSiN 3 :Eu 2?…”

Synthesis of nitride phosphor using entire oxides raw materials and their photoluminescence properties

“…Carbothermal reduction and nitridation (CTRN) method, employing less-expensive oxides/carbonates and carbon reductant as raw materials, was widely reported as a candidate to meet these requirements. [14][15][16][17][18] 17 Our previous work also reported the synthesis of CaAlSiN 3 :Eu 2+ by carbothermal route, using CaH 2 , AlN, Si 3 N 4 , Eu 2 O 3 , and graphite powder as raw materials. 18 It is well-known that employment of less-expensive and airstable oxides raw materials is one of the fascinating superiorities raw materials is one of the fascinating superiorities CTRN method.…”

“…through carbothermal method using CaCO 3 , AlN, Si 3 N 4 , Eu 2 O 3 , and C powder (2014); Kim et al. reported the carbothermal preparation of CaAlSiN 3 :Eu 2+ phosphor using hazardous CaCN 2 as calcium and carbon sources; Our previous work also reported the synthesis of CaAlSiN 3 :Eu 2+ by carbothermal route, using CaH 2 , AlN, Si 3 N 4 , Eu 2 O 3 , and graphite powder as raw materials . It is well‐known that employment of less‐expensive and air‐stable oxides raw materials is one of the fascinating superiorities raw materials is one of the fascinating superiorities CTRN method.…”

“…Carbothermal reduction and nitridation (CTRN) method, employing less‐expensive oxides/carbonates and carbon reductant as raw materials, was widely reported as a candidate to meet these requirements . For examples, Piao et al.…”