Tag Archives: tungsten diselenide

NanoComputers Could Run a Million Times Faster

Transition metal dichalcogenides (TMDCs) possess optical properties that could be used to make computers run a million times faster and store information a million times more energy-efficiently, according to a study led by Georgia State University.

Computers operate on the time scale of a fraction of a nanosecond, but the researchers suggest constructing computers on the basis of TMDCs, atomically thin semiconductors, could make them run on the femtosecond time scale, a million times faster. This would also increase computer memory speed by a millionfold.

There is nothing faster, except light,” said Dr. Mark Stockman, lead author of the study and director of the Center for Nano-Optics and a Regents’ Professor in the Department of Physics and Astronomy at Georgia State. “The only way to build much faster computers is to use optics, not electronics. Electronics, which is used by current computers, can’t go any faster, which is why engineers have been increasing the number of processors. We propose the TMDCs to make computers a million times more efficient. This is a fundamentally different approach to information technology.”

The researchers propose a theory that TMDCs have the potential to process information within a couple of femtoseconds. A femtosecond is one millionth of one billionth of a second. A TMDC has a hexagonal lattice structure that consists of a layer of transition metal atoms sandwiched between two layers of chalcogen atoms. This hexagonal structure aids in the computer processor speed and also enables more efficient information storage. The TMDCs have a number of positive qualities, including being stable, non-toxic, thin, light and mechanically strong. Examples include molybdenum disulfide (MOS2) and tungsten diselenide (WSe2). TMDCs are part of a large family called 2D materials, which is named after their extraordinary thinness of one or a few atoms. In this study, the researchers also established the optical properties of the TMDCs, which allow them to be ultrafast.

The findings are published in the journal Physical Review B.

Source: https://news.gsu.edu/

Strain Improves Performance of Atomically Thin Semiconductor

Researchers in UConn’s Institute of Materials Science significantly improved the performance of an atomically thin semiconductor material by stretching it, an accomplishment that could prove beneficial to engineers designing the next generation of flexible electronics, nano devices, and optical sensors.

In a study appearing in the research journal Nano Letters, Michael Pettes, assistant professor of mechanical engineering, reports that a six-atom thick bilayer of tungsten diselenide exhibited a 100-fold increase in photoluminescence when it was subjected to strain. The material had never exhibited such photoluminescence before.

The findings mark the first time scientists have been able to conclusively show that the properties of atomically thin materials can be mechanically manipulated to enhance their performance, Pettes says. Such capabilities could lead to faster computer processors and more efficient sensors.

The process the researchers used to achieve the outcome is also significant in that it offers a reliable new methodology for measuring the impact of strain on ultrathin materials, something that has been difficult to do and a hindrance to innovation.

Experiments involving strain are often criticized since the strain experienced by these atomically thin materials is difficult to determine and often speculated as being incorrect,” says Pettes. “Our study provides a new methodology for conducting strain-dependent measurements of ultrathin materials, and this is important because strain is predicted to offer orders of magnitude changes in the properties of these materials across many different scientific fields.”

Source: https://today.uconn.edu/