Structural analysis and enhanced photoluminescence via host sensitization from a lanthanide doped BiVO4 nano-phosphor

Abstract

This paper reports the enhanced red photoluminescence from a Eu3+ doped BiVO4 nano-phosphor synthesized through solution combustion method. The XRD and TEM measurements reveal nano-crystalline nature of the sample. The SEM and TEM micrographs show an increase in the particles size on annealing. The EDS measurement confirms the presence of Eu, Bi, V and O elements in the sample. The sample emits red photoluminescence at 615 nm due to 5D0 → 7F2 transition of Eu3+ upon 266 and 355 nm excitations. The emission intensity increases with the increase in the concentration of Eu3+ ion and it is maximum at 1.0 mol%. When the as-synthesized sample is annealed at higher temperature; the emission intensity of the sample enhances upto eight times. The enhancement in the emission intensity is due to an increase in crystallinity and significant reduction in the multi-phonon relaxation of the ions in the excited state, which has been verified by lifetime measurements. The emission intensity is larger for 266 nm excitation (upto two times), which is due to energy transfer from the host (1P1 and 3P1 levels of Bi3+ and CTS of VO43+ ions) to Eu3+ ion. Therefore, the Eu3+ doped BiVO4 nano-phosphor may be a suitable candidate for displays devices.