Luminescence properties of a novel promising red phosphor Na3Gd2-x(BO3)3:xEu3+

The novel red-emitting Na3Gd2-x(BO3)(3):xEu(3+) phosphors were synthesized by a solid-state method. Under near ultraviolet excitation, the phosphors exhibit dominant emission peak at 614 nm and generate bright red light, which is attributed to the electric-dipole transition D-5(0)-> F-7(2). The optimal doping amount of Eu3+ in Na3Gd2-x(BO3)(3):xEu(3+) phosphors is x=0.3 for the maximum emission. The exchange interaction between Eu3+ ions is identified to be the main mechanism in the concentration quenching process. The CIE color coordinates of the Na3Gd2-x(BO3)(3):xEu(3+) phosphors (x=0.650, y=0.350) are close to the NTSC standard values of red. With a relatively high quantum efficiency of 35.2%, Na3Gd2-x(BO3)(3):xEu(3+) red-emitting phosphor is probably a promising candidate for near ultraviolet based white LEDs application. (C) 2016 Elsevier Ltd. All rights reserved.