Optical characteristics and energy transfer between Eu3+ and Dy3+ in Na2CaSiO4:Dy3+, Eu3+ white-emitting phosphor

A new type of white-emitting phosphor Na2CaSiO4:Dy3+, Eu3+ was synthesized through the sol-gel method, and the influences of doping concentration and synthesis temperature on photoluminescence properties and crystal phase were systematically studied. The X-ray diffraction results manifested that the structures of all Na2CaSiO4:Dy3+, Eu3+ phosphors prepared at the temperatures above 1100 ℃ and Na2CaSiO4 are of the same type. Under the excitation of 349 nm, the as-prepared Na2CaSiO4:Dy3+ phosphors showed a blue emission peak at 487 nm and a yellow emission peak at 579 nm attributed to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions. Meanwhile, a white light emission was reached by the combination of the obtained blue and yellow components. By co-doping Eu3+ ions, a characteristic emission peak appeared in red region (617 nm) and it was ascribed to the characteristic 5D0→7F2 transition of Eu3+. The warm white light emission (CCT = 2728 K) was realized with the 0.03Dy3+, 0.02Eu3+ co-doped Na2CaSiO4 phosphor. All results confirmed that the Na2CaSiO4:Dy3+, Eu3+ phosphor with excellent white emission has a potential application in the field of white light emitting diodes.