Unveiling the Ferroelectric Competition and Transition Mechanisms in Hybrid Organic-inorganic Perovskite Heterojunction

The non-volatile spontaneous ferroelectric polarization (FE) field serves as a cornerstone for applying ferroelectric materials in electronic devices, yet it is frequently mitigated by charge trapping (CT) at defect sites. Achieving an effective transition between FE and CT is challenging due to the inherent opposition of the two mechanisms and the uncontrollable CT types in ferroelectric materials. Here, we realized polarity-dependent ferroelectric competition and transition in ferroelectric heterojunction transistors, by integrating a hybrid organic-inorganic perovskite ferroelectric (HOIPFs) layer embedded with electron trapping sites. Through theoretical calculations and experimental validation, we demonstrate competition and transition mechanisms between FE and CT based on the polarity of the semiconductor layer. The electron-majority n-type semiconductor exhibits CT behavior, while the electron-minority p-type semiconductors exhibit the FE mechanism. Leveraging the FE transition, our bipolar ferroelectric heterojunction transistors enable synergistic control of non-volatile FE and volatile CT modulation within a single device, significantly improving the recognition accuracy to 93.9% and a 3.7-fold boost in training efficiency.