Pyroelectricity induced by Schottky interface above the Curie temperature of bulk materials

Summary

Pyroelectricity is a characteristic property of materials that converts temperature fluctuations into electric signals. Ferroelectric materials, such as BaTiO₃, are frequently applied in pyroelectric devices. However, the depolarization of the material above the Curie temperature (T_c) restricts the pyroelectric response of existing ferroelectric-based devices. Here, we propose an alternative approach where the pyroelectric response relates to the built-in electric field generated at a Schottky interface. The indium tin oxide/BaTiO₃/LaNiO₃ film with a Schottky interface exhibits good pyroelectric performance when the operating temperature is ∼20°C higher than the T_c (125°C) of bulk BaTiO₃. The film exhibits a pyroelectric current density of 0.537 μA/cm² and a high cyclic stability at 150°C. The pyroelectric film can operate as a self-powered temperature sensor above the T_c of bulk BaTiO₃, with a response time of 30 ms. This study provides a new strategy to enhance the pyroelectric properties and reliability of ferroelectric-based devices.