Effect of CaCN₂ on the preparation of CaAlSiN₃ :Eu²⁺ phosphors

Highly efficient red-emitting phosphors, CaAlSiN₃ :Eu²⁺ , were successfully prepared by the solid-state method using calcium cyanide (CaCN₂ ) as the single calcium source. The influences of crystallization temperature, crystallization time, calcination mode and compounds ratio on the photoluminescent properties were investigated. The CaAlSiN₃ :Eu²⁺ phosphors were obtained with 1 mol% CaCN₂ by a two-step calcination procedure at 900°C for 2 h and subsequently at 1600°C for 8 h. The CaAlSiN₃ :Eu²⁺ phosphors showed the strongest luminescent intensity at 660 nm when excited by 468 nm. With an increase in crystallization time, the maximum wavelength of the emission was shifted from 644 nm to 660 nm.