Melilite-Structure CaYAl3O7:Eu3+ Phosphor: Structural and Optical Characteristics for Near-UV LED-Based White Light

• Published in: Journal of physical chemistry. C Vol. 116; no. 51; pp. 26850 - 26856
• Main Authors: Park, Seung Hyok, Lee, Kyoung Hwa, Unithrattil, Sanjith, Yoon, Ho Shin, Jang, Ho Gyeom, Im, Won Bin
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 27.12.2012
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronics; Exact sciences and technology; Materials; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optoelectronic devices; Photoluminescence; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Rietveld method; Tetragonal lattices; Photoluminescence; Theoretical study; Method of maximum entropy; X ray diffraction; Emission spectrum; Light emitting diode; Quenching; Calcium Yttrium Aluminates Mixed; Solid state reaction; X ray source; Optoelectronic device
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp307192y

A red-emitting phosphor, CaY1‑x Eu x Al3O7 (CYA:Eu3+), was prepared by conventional solid-state reaction, and its structural properties were investigated by means of Rietveld refinement method and maximum entropy method using an X-ray source. XRD patterns confirm the tetragonal phase of CYA:Eu3+ phosphors. The photoluminescence properties of the samples were investigated for application to white light-emitting diodes (WLEDs). The emission spectrum is dominated by a red peak located at 616 nm due to the 5D0 → 7F2 electric dipole transition of Eu3+ ions. Concentration quenching occurs when the Eu3+ concentration is about 0.35 and the critical transfer distance of the phosphor is also calculated. A white LED fabricated with blue, green, and CYA:Eu3+ red phosphor incorporated with an encapsulant in ultraviolet LEDs (λmax = 396 nm) is discussed.