Synthesis and upconversion luminescent properties of Bi2MoO6:20%Yb3+, 2%Er3+ hollow microsphere with different W6+ ions doping

In this work, W 6+ ions doped Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ samples were successfully synthesized by a facile and modified hydrothermal method . The main morphology of Bi 2 MoO 6 samples were hollow microsphere structure assembled by nanosheets . The particle size was slightly increased as enhancing W 6+ ions doping concentration to 5%, then decreased as the doping concentration increased. Besides, doping W 6+ ions can increase the band gap of products from 2.65 ​eV to 2.71eV. The upconversion emission intensity of all samples was strongly influenced by the W 6+ ions doping concentration. The luminescent intensity enhanced with the doping concentration increasing up to 3%, then decreased when the W 6+ ions concentration further increased. Moreover, the intensity of red emission increased by a large margin than that of green-light region. Besides, the lifetime of 4 F 9/2 states of Er 3+ ions for Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ , 3%W 6+ (τ 655  ​= ​583.64 ​μs) had significant longer lifetime relative to the Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ (τ 655  ​= ​70.29 ​μs).