Near white light emission from K+ ion compensated CaSO4:Dy3+,Eu3+ phosphors

Dy3+:Eu3+ doped calcium sulfate (CaSO4:Dy3+,Eu3+) phosphors co-doped with various K+ compensator concentrations were synthesized by recrystallization method. These orthorhombic phased phosphors showed intense multi-color near white light. The multi-color aspect ratios and the emission life times were strongly dependent on K+-concentration. These results suggest that the rare-earth (Re3+) ions are situated at the sites of Ca2+ and the site occupancy was being compensated by K+ ions. The near white light emission and large lifetimes suggest that present phosphor could be potentially applied as a blue excited white light-emitting phosphor for light emitting diodes.