Preparation and afterglow properties of highly condensed nitridosilicate BaSi7N10:Eu2+ phosphor

A novel nitridosilicate phosphor, BaSi7N10:Eu2+, was synthesized via the nitridation of Ba1−xEuxSi alloy. Oxide impurities in the product can be significantly reduced by the use of alloy precursor to obtain a single phase product. The synthesized BaSi7N10:Eu2+ absorbs strongly in the UV-part of the electromagnetic spectrum and exhibits bluish-green light with a peak wavelength at 475 nm. When temperature is increasing, its emission intensity is decreasing with the broadening full widths at half maximum (FWHM). Interestingly, the afterglow emission of Eu2+ (4f65d1→4f7) could be observed after switching off the 280 nm excitation source, which to the best of our knowledge is found for the first time. This simple, inexpensive and high-yield synthesis route has a significant potential to be applied to other nitrides.