A Nanostructure Phosphor: Effect of Process Parameters on the Photoluminescence Properties for Near-UV WLED Applications

• Published in: Journal of inorganic and organometallic polymers and materials Vol. 22; no. 4; pp. 737 - 743
• Main Authors: Sameie, H., Salimi, R., Sabbagh Alvani, A. A., Sarabi, A. A., Moztarzadeh, F., Mokhtari Farsi, M. A., Eivaz Mohammadloo, H., Sabbagh Alvani, M., Tahriri, M.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.07.2012
• Subjects: Chemistry; Chemistry and Materials Science; Emittance; Indium gallium nitrides; Inorganic Chemistry; Nanostructure; Organic Chemistry; Phosphors; Photoluminescence; Polymer Sciences; Process parameters; Scanning electron microscopy; Transmission electron microscopy; Nanostructures; Sol–gel; Photoluminescence; Rare-earths
• ISSN: 1574-1443; 1574-1451
• DOI: 10.1007/s10904-011-9627-y

The sol–gel preparative method was employed to synthesize SrZn 2 Si 2 O 7 :Eu nanostructure phosphors for white-light emitting diodes. The effects of calcination temperature and atmosphere as two important process parameters on the structural, morphological and optical properties were investigated using comprehensive characterization methods such as X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM) and photoluminescence spectra. The obtained phosphors are efficiently excited from 340 to 400 nm, which matches the near UV emitting InGaN chip and emits strong band peaking at 481 nm due to 4f 6 5d 1 ( 2 D )  →   4f 7 ( 8 S 7/2 ) transition of Eu 2+ ions. In this europium-doped host lattice, a partial reduction of Eu 3+ to Eu 2+ at high temperature during the synthesis in air according to the charge compensation model is perceived. Furthermore, for this sample forbidden f–f transitions of Eu 3+ are observed. Finally, using Scherrer’s equation the crystallite size of the optimum products with color coordination of x  = 0.176, y  = 0.193 is estimated at ~30 nm, which was consistent with TEM observations.