Energy density capability and upconversion luminescence in Er3+/Yb3+-codoping BNT-based ferroelectric thin films

Abstract

Smart materials with multiple functions are the preferred materials for technological applications in military, medical, aerospace science and technology, and architecture. However, developing newly single-phase material coupling with multiple functions is still subjects with enormous challenge. Herein, the rare-earth elements Er3+/Yb3+ substitution of lead-free 0.7Bi0·5Na0·5TiO3-0.3Sr0·7Bi0·2TiO3 (BNT-SBT) ferroelectric thin films are designed and fabricated to improve energy storage capability and upconversion luminescence. Optimized BNT-SBT thin films achieves superior discharged energy density of 52.4 J/cm3 with high efficiency of 70.2%, as well as excellent temperature stability (RT to 150 °C) and fatigue endurance (107 circles). Additionally, the emission color of BNT-SBT thin films could be controlled through changing Yb3+ ion concentrations. More importantly, the maximum sensor sensitivity of the Er3+/Yb3+ codoped BNT-SBT thin films could reach 0.0049 K−1 at 363 K. This contribution paves a novel avenue for preparing lead-free multifunctional ferroelectric thin films, which are interested in potential application in the field of optoelectronic devices.