Bright green emission and enhanced electrical properties in SrBi4-xHoxTi4O15 multifunctional ceramics

- Ho3+ doping promotes the electric properties and temperature stability of SBT.
- Bright green emission is achieved in Ho3+-modified SBT ceramics.
- Samples exhibit a higher insulation resistivity even at 700 °C.
- The XPS verified that SBT-xHo exists in the form of Sr2+, Bi3+, Ho3+, Ti4+, O2−.

Ho3+-modified SrBi4Ti4O15 ceramics with bright green light emission and enhanced electrical properties were fabricated by a conventional solid-state reaction method. Upon visible light irradiation, samples exhibit a strong green emission located at 546 nm and a weak red emission at 653 nm. These two emissions corresponding to the intra f-f transition from the excited state 5S2 to the ground state 5I8 and the 5F5→5I8 transition of Ho3+, respectively. The relative intensity of green and red emissions is related to the Ho3+ contents closely, due to the concentration quenching effect. Moreover, it is also found that Ho3+ doping significantly enhanced the electrical properties. At x = 0.008, samples exhibit optimal electrical properties and excellent piezoelectric temperature stability for the SBT-xHo system. These results reveal that these materials have good application prospect in future optical temperature sensors by integrating its luminescent and piezoelectric properties.