Crystal phase induced upconversion enhancement in Er3+/Yb3+ doped SrTiO3 ceramic and its temperature sensing studies.

Through doping of Er3+/Yb3+ ions the SrTiO3 perovskite ceramic is turned into an optically active material keeping its ferroelectric property intact. A huge enhancement of around 20 times in upconversion (UC) emission intensity is observed due to the transformation of cubic crystal structure to tetragonal phase. The intensity ratio of green to red band is found too high to neglect the contribution from the red emission band, which is not observed normally in such type of relatively moderate phonon frequency materials containing Yb3+/Er3+ ions. The change in emission intensity is reflected in the decay time measurement. Optical temperature sensing behavior based on FIR technique also has been discussed for Er3+/Yb3+ doped SrTiO3 ceramic.