Monday, August 22, 2022

Superlattices Could Make Bulky Capacitors Obsolete

Good news!

"... One roadblock to shrinking present-day electronics is the relatively large size of their capacitors. Now scientists have developed new “superlattices” that might help build capacitors as small as one-hundredth the size of conventional ones. ...
 Antiferroelectric materials could help solve this problem. Like magnets, which possess north and south poles, electric charges within materials become separated into positive and negative poles. Antiferroelectrics are materials in which these “electric dipoles” are generally oriented in opposing directions, leading to an overall zero electric polarization. However, when antiferroelectrics are exposed to a strong enough electric field, they can switch to a highly polarized state, resulting in large energy densities. ...
However, relatively few natural antiferroelectric materials are known. In a new study, Aramberri and his colleagues sought to engineer artificial structures that could act like antiferroelectrics. ...
The team then constructed superlattices made of ferroelectric lead titanate (PbTiO3) and paraelectric strontium titanate (SrTiO3). These superlattices got their name because the lead titanate and strontium titanate, themselves arrayed in lattice structures, are also placed in thin, alternating layers with each other. ..."

From the abstract:
"The polarization response of antiferroelectrics to electric fields is such that the materials can store large energy densities, which makes them promising candidates for energy storage applications in pulsed-power technologies. However, relatively few materials of this kind are known. Here, we consider ferroelectric/paraelectric superlattices as artificial electrostatically engineered antiferroelectrics. Specifically, using high-throughput second-principles calculations, we engineer PbTiO3/SrTiO3 superlattices to optimize their energy storage performance at room temperature (to maximize density and release efficiency) with respect to different design variables (layer thicknesses, epitaxial conditions, and stiffness of the dielectric layer). We obtain results competitive with the state-of-the-art antiferroelectric capacitors and reveal the mechanisms responsible for the optimal properties."

Superlattices Could Make Bulky Capacitors Obsolete - IEEE Spectrum: Researchers hope artificial antiferroelectric capacitors could help miniaturize electronics further



No comments: