1 research outputs found
Unveiling the double-well energy landscape in a ferroelectric layer
The properties of ferroelectric materials, which were discovered almost a century agoĀ¹ , have led to a huge range of applications, such as digital information storageĀ² , pyroelectric energy conversionĀ³ and neuromorphic computingā“ā»āµ . Recently, it was shown that ferroelectrics can have negative capacitanceā¶ā»Ā¹Ā¹, which could improve the energy efficiency of conventional electronics beyond fundamental limitsĀ¹Ā²ā»Ā¹ā“. In LandauāGinzburgāDevonshire theoryĀ¹āµā»Ā¹ā·, this negative capacitance is directly related to the doublewell shape of the ferroelectric polarizationāenergy landscape, which was thought for more than 70 years to be inaccessible to experimentsĀ¹āø. Here we report electrical measurements of the intrinsic double-well energy landscape in a thin layer of ferroelectric Hfā.ā
Zrā.ā
Oā. 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 applicationsĀ¹ā¹. In addition, the Hfā.ā
Zrā.ā
Oā used in this work is currently the most industry-relevant ferroelectric material, because both HfOā and ZrOā thin films are already used in everyday electronicsĀ²ā°. This could lead to fast adoption of negative capacitance effects in future products with markedly improved energy efficiency