Memory devices

The human brain can effortlessly process complex sensory information and learn from experiences, while a computer cannot. And, the brain does all this by consuming less than half as much energy as a laptop. One of the reasons for the brain's energy efficiency is its structure. The individual brain cells – the neurons and their connections, the synapses – can both store and process information. In computers, however, the memory is separate from the processor, and data must be transported back and forth between these two components. The speed of this transfer is limited, which can slow down the whole computer when working with large amounts of data.

One possible solution to this problem are novel computer architectures that are modeled after the human brain. To this end, scientists are developing 'memristors': components that, like brain cells, combine data storage and processing. A team of researchers from Empa, ETH Zurich and the Politecnico di Milano has developed a memristor based on perovskite materials that is more powerful and easier to manufacture than its predecessors.

Researchers from National Taiwan Normal University and Kyushu University have developed a new memory device, readable through both electrical and optical methods, that needs only perovskites to simultaneously store and visually transmit data.

Schematic of the CsPbBr3 QD-based LEM device. Image from Nature Communications

By integrating a light-emitting electrochemical cell with a resistive random-access memory that are both based on perovskite, the team achieved parallel and synchronous reading of data both electrically and optically in a 'light-emitting memory.'

A research team led by Professor Jang-Sik Lee of Pohang University of Science and Technology (POSTECH) has developed a halide perovskite-based memory with ultra-fast switching speed.

Resistive switching memory is a promising contender for next-generation memory device due to its advantages of simple structure and low power consumption. Various materials have been previously studied for resistive switching memory. Among them, halide perovskites are receiving much attention for use in the memory because of low operation voltage and high on/off ratio. However, halide perovskite-based memory devices have limitations like slow switching speed which hinder their practical application in memory devices.

Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have reported a breakthrough in energy-efficient phototransistors - devices that could someday help computers process visual information similarly to the human brain and be used as sensors in applications like self-driving vehicles.

The structures rely on metal-halide perovskites. Jeffrey Blackburn, a senior scientist at NREL and co-author of a new paper outlining the research, said: 'In general, these perovskite semiconductors are a really unique functional system with potential benefits for a number of different technologies'. 'NREL became interested in this material system for photovoltaics, but they have many properties that could be applied to whole different areas of science.'

Researchers at Linköping University in Sweden have announced the development of an optoelectronic magnetic double perovskite. The discovery could open the door to combining spintronics with optoelectronics for rapid and energy-efficient information storage.

The team explains that one type of perovskite that contains halogens and lead has recently been shown to have interesting magnetic properties, opening the possibility of using it in spintronics. Spintronics is thought to have huge potential for the next generation of information technology, since information can be transmitted at higher speeds and with low energy consumption. However, magnetic properties of halide perovskites have until now been associated only with lead-containing perovskites, which has limited the development of the material for both health and environmental reasons.

Australia-based RRAM developer 4DS Memory announced that it has raised a total of $7.6 million AUD ($5.45 million USD) in two financing round. The 4DS memory cell is constructed using an advanced perovskite material, which has the same crystal structure as the inorganic compound calcium titanium oxide.

4DS Memory says that it will use the funds to further develop its Interface Switching ReRAM technology with imec and Western Digital's subsidiary, HGST.

A Pohang University of Science & Technology (POSTECH) research team has designed a halide perovskite material for next-generation memory devices. Characteristics like low-operating voltage and high-performance resistive switching memory could mean great commercialization potential.

As rapid distribution and transmission of high-quality contents are growing rapidly, it is critical to develop reliable and stable semiconductor memories. To this end, the POSTECH research team succeeded in designing an optimal halide perovskite material (CsPb₂Br₅) that can be applied to a ReRAM device by applying first-principles calculation based on quantum mechanics.

Physicists at the École polytechnique fédérale de Lausanne (EPFL) in Switzerland have used perovskite materials to alter a magnetic bit's polarity with light, potentially opening the door to denser and faster disk drives using magneto-optical technology.

Researchers László Forró, Bálint Náfrádi, Péter Szirmai and Endre Horváth suggest magneto-optical drives using this method could be physically smaller, faster and cheaper than today's disk drives. They also say it is an alternative to heat-assisted magnetic recording (HAMR).

scientists at the University of Warwick, Oxford University, University of Cambridge, Los Alamos National Laboratory and University at Buffalo in the U.S have found a colossal magnetoresistance at terahertz frequencies at room temperature in high-quality functional perovskite-based nanocomposites. This may find use in nanoelectronics and in THz optical components controlled by magnetic fields.

Electronics that can read and write data at terahertz frequency, rather than at a few gigahertz, can lead to faster performance. Creating such devices would be aided by the use of materials that can undergo a huge change in how easily they conduct electricity in response to a magnetic field at room temperature. Scientists believe thin films of perovskite oxides hold promise for such uses, but such behavior has until now never been seen at these frequencies in these films.

Australia-based RRAM developer 4DS Memory announced that it has signed an agreement with Belgium-based imec to develop a transferable manufacturing process for its technology. As part of the agreement the two parties will demonstrate the process with a 1Mbit test chip.

The 4DS memory cell is constructed using an advanced perovskite material, which has the same crystal structure as the inorganic compound calcium titanium oxide. The cells have no filaments and are so claim to be easier to scale compared to filamentary RRAM.