Fig. 7: Pyroelectric property measured by Pyroelectric Properties Testing System and schematic illustration for the mechanisms of pyroelectric energy harvesting.
a The temperature-dependent pyroelectric coefficient of BNT-BZT-xGaN ceramics with different content of GaN, b the temperature at peak pyroelectric coefficient (Tpeak), the temperature at non-ergodic to ergodic relaxor state (TFR) and peak pyroelectric coefficient (ppeak) of BNT-BZT-xGaN ceramics with x = 0–0.2 wt%. c, d The illustration for the mechanisms of pyroelectric energy harvesting for BNT-BZT and BNT-BZT-xGaN with x = 0.1 wt%, respectively (At a steady state (dT/dt = 0), in comparison with BNT-BZT sample, the poled electric dipoles of BNT-BZT-xGaN with x = 0.1 wt% ceramic absorb a greater quantity of opposite electrical charge on both sides of samples due to the enhanced dipole pinning effect, providing the potential for giant pyroelectric effect. When dT/dt ˃ 0, the electric dipoles in BNT-BZT-xGaN with x = 0.1 wt% ceramic oscillate within a larger degree of alignment, leading to larger currents in the circuits compared with that of BNT-BZT samples.).
