Multiple Charge Transfer Bands Induced Broad Excitation Eu 3+ Red Emission in a Vanadium Phosphate System for White Light-Emitting Diodes.

In order to realize broad excitation and narrow emission red light phosphor, a new vanadium phosphate Ba 2 BiV 2 PO 11 was selected as a host for Eu 3+ . Monitored at 619 nm, a wide band from 240 to 400 nm could be observed and inferred to be composed of Eu 3+ -O 2- and V 5+ -O 2- charge transfer bands, which could make it match well with the UV chip and the blue chip along with the characteristic excitation of Eu 3+ at 465 nm. Under 354 nm excitation, the sample could emit high color purity red light, and the thermal quenching integral intensity showed good thermal stability. The generation of charge transfer bands was investigated in detail combined with the luminescence properties and the structure of the matrix. Moreover, the as-prepared phosphor could improve the white light performance of blue chip-activated YAG:Ce 3+ and n -UV chip-activated tricolor phosphors. All the results indicated the multiple application potential of Ba 2 BiV 2 PO 11 :Eu 3+ for white light-emitting diodes.