Giant tunnelling electroresistance in atomic-scale ferroelectric tunnel junctions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38267445.
- Also identified by DOI 10.1038/s41467-024-44927-7 and PMC identifier 10808203.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ferroelectric tunnel junctions are promising towards high-reliability and low-power non-volatile memories and computing devices. Yet it is challenging to maintain a high tunnelling electroresistance when the ferroelectric layer is thinned down towards atomic scale because of the ferroelectric structural instability and large depolarization field. Here we report ferroelectric tunnel junctions based on samarium-substituted layered bismuth oxide, which can maintain tunnelling electroresistance of 7 × 10<sup>5</sup> with the samarium-substituted bismuth oxide film down to one nanometer, three orders of magnitude higher than previous reports with such thickness, owing to efficient barrier modulation by the large ferroelectric polarization. These ferroelectric tunnel junctions demonstrate up to 32 resistance states without any write-verify technique, high endurance (over 5 × 10<sup>9</sup>), high linearity of conductance modulation, and long retention time (10 years). Furthermore, tunnelling electroresistance over 10<sup>9</sup> is achieved in ferroelectric tunnel junctions with 4.6-nanometer samarium-substituted bismuth oxide layer, which is higher than commercial flash memories. The results show high potential towards multi-level and reliable non-volatile memories.