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

摘要： A series of NaBi(MoO4)2:Eu3+ and 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 °C. The effects of the synthetic temperature and Eu3+ concentration on the luminescent properties of the NaBi(MoO4)2:Eu3+ phosphors were investigated. Under blue excitation at 464 nm, the NaBi(MoO4)2:Eu3+ sample exhibited a strong red emission peak at 618 nm, which originated from the 5D0→7F2 transition of Eu3+. Furthermore, Gd3+ ions were codoped into NaBi(MoO4)2:Eu3+ to enhance the luminescent intensity of NaBi(MoO4)2:Eu3+, Gd3+ 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.