Tuning photoluminescence response by electric field in the lead-free piezoelectric Na1/2Bi1/2TiO3-BaTiO3

We show that an electrically soft ferroelectric host can be used to tune the photoluminescence (PL) response of rare-earth emitter ions by external electric field. The proof of this concept is demonstrated by changing the PL response of Eu+3 ion by electric field on a model system Eu-doped 0.94Na1/2Bi1/2TiO3-0.06BaTiO3. We also show that new channels of radiative transitions, forbidden otherwise, open up due to positional disorder in the system, which can as well be tuned by electric field.Comment: 13 pages 5 figure

Influence of electric field on the Eu+3 photolumiscence in lead-free ferroelectric Na1/2Bi1/2TiO3

Eu modified Na1/2Bi1/2TiO3 (NBT) was investigated for electric-field induced Eu+3 photoluminescence (PL) and structural changes. Detailed analysis revealed that below a critical Eu composition electric field irreversibly suppresses the structural heterogeneity inherent of the host matrix NBT and brings about a long range ferroelectric state with rhombohedral (R3c) distortion. PL study revealed that structural disorder on the nano-scale opens new channels of radiative transitions which can be suppressed by electric field. This study suggests that Eu+3 luminescence can be used to probe the relative degree of field induced structural ordering in relaxor ferroelectrics and also in high performance piezoelectric alloys where electric field couples very strongly with the lattice and structural degrees of freedom.Comment: 19 pages, 9 figure