Giant pyroelectricity via doping and interface engineering

Pyroelectricity plays a crucial role in energy harvesting and sensing. High pyroelectric coefficients are the focus of optimizing pyroelectrics. Elevated pyroelectric coefficients not only contribute to the efficiency of energy conversion and signal resolution to be enhanced but also facilitate device miniaturization and cost reduction. However, the pyroelectric coefficients are typically below 1,000 μC/m²K. Here, we achieve a 14-fold enhancement in the pyroelectric coefficient of 8,194 μC/m²K at room temperature for lead magnesium niobate-lead titanate (PMNT) single crystals. This enhancement can be attributed to a synergistic strategy of doping and interface engineering, which enables the coupling of both intrinsic and interface pyroelectricity. Moreover, doping and interface engineering, respectively, contribute to intrinsic pyroelectricity by altering domain structure and polarization and through interface pyroelectricity by introducing polar symmetry. This synergistic strategy provides a framework to design high-performance pyroelectrics for applications in thermal batteries, infrared sensors, and medical imaging devices.