Novel Ce3+ Phophors for Luminescent Applications

With the discovery of the UV/blue InGaN LED, it is now possible to obtain white light based on wide band gap semiconductors and phosphor materials. This combination will give rise to comparable light output spectrum as the sun and cost efficient lighting source. The UV/blue light can originate from the InGaN LED. For the complementary color, we intend to synthesize phosphors that absorb some of the blue light and convert the photons into higher wavelength yellow photons that will combine with the blue ones to give white light. Hopefully, solid state lighting will be a suitable (efficient and cost less) replacement to current incandescent and florescent lights. We focused on Ce3+ based phosphors since cerium atoms are characterized by f to d transitions that can be altered by the crystal field and then tune in term of the luminescence properties.

To accomplish these goals, we intend to change the emission/excitation properties of pre-existing phosphors as well as synthesize new phosphors. To change luminescent properties, we attempted to modify the host matrix especially the crystallographic site of Ce3+ atoms. To synthesize new phosphors, we synthesized new hosts and adjusted the amount of Ce3+, particle size, and synthesis conditions.