The properties of ferroelectric materials, which were discovered almost a century ago¹ , have led to a huge range of applications, such as digital information storage² , pyroelectric energy conversion³ and neuromorphic computing⁴⁻⁵ . Recently, it was shown that ferroelectrics can have negative capacitance⁶⁻¹¹, which could improve the energy efficiency of conventional electronics beyond fundamental limits¹²⁻¹⁴. In Landau–Ginzburg–Devonshire theory¹⁵⁻¹⁷, this negative capacitance is directly related to the doublewell shape of the ferroelectric polarization–energy landscape, which was thought for more than 70 years to be inaccessible to experiments¹⁸. Here we report electrical measurements of the intrinsic double-well energy landscape in a thin layer of ferroelectric Hf₀.₅Zr₀.₅O₂. To achieve this, we integrated the ferroelectric into a heterostructure capacitor with a second dielectric layer to prevent immediate screening of polarization charges during switching. These results show that negative capacitance has its origin in the energy barrier in a double-well landscape. Furthermore, we demonstrate that ferroelectric negative capacitance can be fast and hysteresis-free, which is important for prospective applications¹⁹. In addition, the Hf₀.₅Zr₀.₅O₂ used in this work is currently the most industry-relevant ferroelectric material, because both HfO₂ and ZrO₂ thin films are already used in everyday electronics²⁰. This could lead to fast adoption of negative capacitance effects in future products with markedly improved energy efficiency.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:81518 |
| Date | 17 October 2022 |
| Creators | Hoffmann, Michael, Fengler, Franz P. G., Herzig, Melanie, Mittmann, Terence, Max, Benjamin, Schroeder, Uwe, Negrea, Raluca, Lucian, Pinitilie, Slesazeck, Stefan, Mikolajick, Thomas |
| Publisher | Springer |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/acceptedVersion, doc-type:article, info:eu-repo/semantics/article, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 1476-4687, https://doi.org/10.1038/s41586-018-0854-z, info:eu-repo/grantAgreement/European Commission/H2020 | ECSEL-RIA/692519//Ultra-Low PoweR technologIes and MEmory architectures for IoT/PRIME |
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