Effects of Gd3+ codoping on the enhancement of the luminescent properties of a NaBi(MoO4)2:Eu3+ red-emitting phosphors

A series of NaBi(MoO4)(2):Eu3+, Gd3+ phosphors were prepared using a sol-combustion method. NaBi(MoO4)(2):Eu3+ with a tetragonal scheelite structure was obtained by heat treatment at 600-800 degrees C. The effects of the synthetic temperature and Eu 3 + concentration on the luminescent properties of the NaBi(MoO4)(2):Eu3+ phosphors were investigated. Under blue excitation at 464 nm, the NaBi(MoO4)(2):Eu(3+ )sample exhibited a strong red emission peak at 618 nm, which originated from the D-5(0) -> F-7(2) transition of Eu3+. Furthermore, Gd3+ ions were codoped into NaBi(MoO4)(2):Eu3+ to enhance the luminescent intensity of NaBi(MoO4)(2):Eu3+ due to energy transfer between Gd3+ and Eu3+. The results indicated that the NaBi(MoO4)(2):Eu3+, Gd3+ red phosphor could be applied to white light-emitting diodes to achieve excellent properties, such as a high color rendering index and low correlated color temperature. (C) 2019 Elsevier B.V. All rights reserved.