Preparation of silicate-based red phosphors with a patterned nanostructure via metabolic insertion of europium in marine diatoms

Patterned, nanostructured, silicate-based phosphors with the capacity to convert light from near-UV to red wavelengths were synthesized via metabolic insertion of europium in live Navicula. Structural and photoluminescent properties of the sample were analyzed by X-ray diffraction, field emission scanning electron microscopy and a fluorescence spectrophotometer. Red emission (6.14 nm, D-5(0)-F-7(2)) was obtained at 394 nm due to the F-7(0)-L-5(5) transition of Eu3+. The novel red phosphors are a suitable candidate for white LED lighting applications because of their particle size, large surface area, and broadened excitation band in the near-UV range. (C) 2013 Elsevier B.V. All rights reserved.