Synthesis and spectral properties of rare-earth free tunable full-color-emitting Si-BCNO phosphors

The rare-earth free tunable full-color-emitting Si-BCNO phosphors were synthesized at low temperature (below 800 °C) for 45 min by solid state reaction method using urea, boric acid, polyethylene glycol and silica as raw materials. The prepared samples exhibited single, distinct and broad photoluminescence emission bands varied from blue (470 nm) to red (620 nm) upon excitation at 370 nm by varying the concentrations of Si and sintering temperatures. The decay curves signified that the luminescence was induced by two luminescence centers, related to longer lifetime τ1 and shorter lifetime τ2. The temperature-dependent PL intensity of the phosphor has been also investigated, which performs good thermal stability. It is believed that the Si-BCNO phosphor could be a possible material for multicolor light-emitting diodes.