Bright green upconversion emission and enhanced ferroelectric polarization in Sr1−1.5xErxBi2Nb2O9

• UC process and FE properties were first investigated in SBN:xEr3+ ceramics.
• Bright UC green emission of SBN:xEr3+ system was first observed at room temperature.
• Two-photon energy transfer process was confirmed for UC green and red emission.
• Remarkably enhanced FE polarization of SBN:xEr3+ was reported for SBN:xEr3+.

Upconversion (UC) luminescence and ferroelectric (FE) polarization properties were first investigated in polycrystalline Er3+-doped SrBi2Nb2O9 (SBN:xEr3+) samples. Bright UC green and weak UC red emission, originating from (2H11/2, 4S3/2)–4I15/2 and 4F9/2–4I15/2 transitions, respectively, was confirmed to be a two-photon energy transfer process. The UC green luminescence can be seen by the naked eye at room temperature. The optimal UC green emission was obtained when x = 5 mol.% in SBN:xEr3+. Furthermore, it is surprisingly found that a proper Er3+ doping can also remarkably enhance the FE polarization of SBN:xEr3+.

UC-PL spectrum of SBN:xEr3+ with x = 5 mol.% under the 980 nm IR excitation. The left inset of this figure shows a luminescence photograph of this sample. The right inset of this figure gives a P–E hysteresis loop at room temperature.Figure optionsDownload high-quality image (53 K)Download as PowerPoint slide