[16p-2B-1~9] 13.9 Optical properties and light-emitting devices

[16p-2B-9] Preparation, crystal structures and luminescence properties of (Ba_0.99Eu_0.01)Al₃Si₄N₉

〇Fumitaka Yoshimura¹, Yamane Hisanori² (1.Mitsubishi Chemical Gr. Sci. Tech. Res. Center, Inc., 2.IMRM, Tohoku Univ.)

Keywords:phosphor

Crystalline grains of (Ba_0.99Eu_0.01)Al₃Si₄N₉ were obtained from samples synthesized by heating mixtures of binary nitride powders. The fundamental reflections of electron diffraction (ED) and X-ray diffraction (XRD) measured for the grains could be indexed with orthorhombic cell parameters: a =10.028(2) Å, b = 53.353(9) Å, and c = 5.9215(11) Å. Streaks and diffuse lines along the b axis were observed in the ED and XRD photographs, indicating stacking faults. A statistical average structure was analyzed using the intensity data of the fundamental reflections with the space group Fdd2. Local structure models were presented based on the average structure. Similar streaks and diffuse lines with fundamental reflections indexed with monoclinic cell parameters: a =5.8376(4) Å, b =26.6895(12) Å, c=5.8393(3) Å, and β=118.8428(15)º, were also observed in the XRD oscillation photographs of another grain. The mixture of the grains having the orthorhombic and monoclinic fundamental structures emitted blue-green light with a peak wavelength of 500 nm under 400 nm excitation.