Bi0.5Na0.5TiO3 (BNT)-based relaxors are considered as potential candidates for pyroelectric applications due to their excellent pyroelectric performances. However, the excellent pyroelectric response in BNT-based relaxors is generally accompanied by a rapid decrease in the depolarization temperature Td, limiting the operation temperature. Herein, we find that the mixed non-ergodic and ergodic relaxor states (a kind of transition system) can promote polarization rotation and remain the reversibility of polarization transformation simultaneously, thereby improving pyroelectric performances and maintaining the Td . The Li+-doped BNKT-based relaxors which possess such a transition state exhibit excellent room temperature (RT) pyroelectric coefficients (1247 μCm−2K−1), and also, the Td can maintain at 69℃. This work provides a strategy for further insight into the enhanced pyroelectric response, which promotes the development of eco-friendly pyroelectric applications (such as infrared detection, temperature sensors, and pyroelectric energy harvesting).

Optimized pyroelectric behaviors by constructing the nonergodic-ergodic transition state