Hydrothermal synthesis and luminescence properties of Eu3+ and Sm3+ codoped BiPO4

Eu3+/Sm3+ codoped BiPO4 phosphors were synthesized via a facile hydrothermal method with surfactant-free environment. The X-ray diffraction analysis demonstrated that the samples possessed the standard BiPO4 monoclinic structure. Scanning electron microscopy images showed that all samples composed of well-dispersed, micrometer-sized crystals with shuttle-like shape. Energy transfer from Sm3+ to Eu3+ was confirmed by the luminescence spectra and the decay processes of Sm3+ 4G5/2→6H5/2 emission. Orange-red luminescence could be obtained in Eu3+/Sm3+ codoped BiPO4 phosphors. The average lifetime of Sm3+ 4G5/2→6H5/2 emission decreased from 2.70 ms in BiPO4:0.03Sm3+ to 2.37 ms in BiPO4:0.03Sm3+,0.05Eu3+. The strong and wide absorption band around 395 nm, originating from both 7F0→5L6 transition of Eu3+ and 6H5/2→4K11/2 transition of Sm3+, endowed BiPO4:Eu3+,Sm3+ phosphors with the potential application in the fields of near UV-excited white-light-emitting diodes.