Jackson State University
Chemistry/ Pre-Chemical Engineering
Faculty Sponsor's Department(s):
OPTIMIZING CERIUM IN SODIUM YTTRIUM SILICATE POSPHORS FOR SOLID STATE WHITE LIGHTING
Light-emitting diodes (LEDs), a semi-conductor light source, are advantageous because they have lower energy consumption, longer life spans, and are smaller than traditional light sources. However, because LEDs are a monochromatic light source they require the use of a phosphor to convert the light producing white light with excellent color quality. Substituting cerium in a series of sodium yttrium silicates, and , yields a pair of blue emitting phosphors when excited with a UV-LED. Using a microwave-assisted heating, we achieved high temperatures and a reducing environment necessary to react our starting materials. The products were characterized using power X-ray diffraction to determine the purity and optically characterized by fluorescence spectrometry. The excitation of was 360 nm and produced a blue emission, while the absorbed 330 nm producing a violet emission. The optimal concentrations for and were determined.