Credit By: TECH EXPLORIST
Protons that cause repeated phase changes in ferroelectric materials, according to research headed by KAUST, may be used to create high-performance memory devices, such as brain-inspired or neuromorphic computing circuits.
This follows a press release from the organization released on Sunday.
Ferroelectrics, like indium selenide, are intrinsically polarized materials that change polarity when exposed to an electric field, making them desirable for use in-memory technologies. The resulting memory devices have limited storage capacities but outstanding maximum read/write endurance and speed. However, they also require low operating voltages. This is because only a few ferroelectric phases may be stimulated by current techniques, and it is difficult to experimentally capture these phases, according to Xin He, who co-led the study under the direction of Fei Xue and Xixiang Zhang.
The new strategy
The team’s innovative method relies on the protonation of indium selenide to produce a wide variety of ferroelectric phases. It was composed of ferroelectric material deposited in a transistor constructed of a stacked heterostructure supported by silicon.
“They deposited a multilayered indium selenide film atop the heterostructure, which comprised a porous silica layer at the top and a platinum layer sandwiched between an insulating sheet made of aluminum oxide in the middle. The porous silica served as an electrolyte and provided protons to the ferroelectric film, while the platinum layer served as electrodes for the applied voltage, according to the statement.
The researchers then gradually added or subtracted protons from the ferroelectric layer by varying the applied voltage. This led to several ferroelectric phases with varying protonation levels, essential for implementing multilevel memory systems with significant store capacity.
The press release states, “Higher positive applied voltages enhanced protonation, whereas higher negative voltages of higher amplitudes depleted protonation levels to a greater extent.”
The proximity of the film layer to silica affected the protonation levels as well. They gradually declined to approach minimal levels in the top layer after reaching maximum values in the bottom layer, which was in contact with silica.
However, the discovery that the proton-induced ferroelectric phases recovered to their initial state when the applied voltage was removed astonished the researchers.
Because protons spread out of the substance and into the silica, Xue said, “We observed this unusual phenomenon.”
The researchers then created a film that showed continuous, smooth contact with silica, leading to a device that runs at a voltage of less than 0.4 volts, perfect for creating low-power memory devices.
The ability to lower operating voltage was one of the most significant challenges. Still, as Xue explained, “We realized that the proton-injection efficiency over the interface governed operating voltages and could be tuned accordingly.”
In the release, Xue stated, “We are dedicated to creating ferroelectric neuromorphic computer devices that are more energy-efficient and run faster.
