Efficient Sensitization of Eu 3+ Emission by Tb 3+ in Ba 3 La(PO 4 ) 3 under VUV-UV Excitation: Energy Transfer and Tunable Emission

The work presents the VUV-UV–vis photoluminescence of Ba 3 La(PO 4 ) 3:Ln 3+ (Ln = Tb, Eu) prepared by a high-temperature solid-state reaction route. The excitation and emission spectra, the fluorescence decays, and the time-resolved emission spectra were measured and discussed in detail. The results reveal that Tb 3+ can efficiently transfer excitation energy to Eu 3+ via its 5d and 4f states and therefore sensitizes Eu 3+ emission under VUV-UV excitation, resulting in tunable emission in a large color gamut.