Lanthanide phosphates represent a class of materials with significant technological importance

and are extensively applied as laser

ceramic

sensor

and phosphor materials.Among various lanthanide phosphate compounds

the lanthanide doped lanthanide phosphates are extremely suitable for applications as phosphors owing to the transition between energy levels of lanthanide ions.The development and application of mercury-free lamps and plasma display panels(PDPs) induce considerable research interest in vacuum ultraviolet(VUV) excitation.Conventional solid-state reaction route requires high temperature calcinations

milling and grinding processes.The phosphor particles obtained by this method have an irregular shape

coarse surface

wide size distribution

and high aggregation.The solution co-precipitation technique was used to synthesize the green-emitting phosphor YPO

4

:Tb.Results indicate that the YPO

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:Tb phosphor particles prepared by co-precipitation technique have almost spherical shape

smooth surface

narrow size distribution in 1~2m range

and low aggregation.The VUV excitation and emissions under 147 nm excitation are investigated.The VUV excitation spectrum of Tb doped YPO

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suggests that phosphors have a high Absorption near 147 nm

which is ascribed to the host Absorption.The luminous emission of YPO

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:Tb precipitates calcinated in 800~1000 ℃ increases with the increase of calcination temperature due to the improvement of crystallinity. The luminous efficiency of YPO

4

:Tb obtained from solution co-precipitation is higher than that obtained from conventional solid state route.