Single Crystal Growth and Crystal Structure Analysis of Novel Orange-Red Emission Pure Nitride CaAl(2)Si(4)N(8):Eu(2+) Phosphor

[Image: see text] Single crystal of novel orange-red emission CaAl(2)Si(4)N(8):Eu(2+) phosphor was grown by our original vapor phase technique, and the precise crystal structure was investigated for the first time by single crystal X-ray diffraction analysis. The crystal structure of CaAl(2)Si(4)N(8):Eu(2+) single crystal was verified to be an α-Si(3)N(4)-type trigonal structure (space group P31c) with a = 0.79525(9) nm, c = 0.57712(8) nm, and z = 2. The Ca atoms were coordinated to seven nitrogen atoms and located in the three-dimensional framework formed by (Al, Si)N(4) tetrahedra. The single-crystal CaAl(2)Si(4)N(8):Eu(2+) phosphors exhibited a broad reddish-yellow emission with a peak at 600 nm under near-UV and blue light excitation. When increasing the temperature up to 150 °C, the emission intensity of the CaAl(2)Si(4)N(8):Eu(2+) phosphor decreased to 88% of the initial value at 25 °C.