Silicene is the new wonder material on the block, so move over, graphene, and make way for the promising substance which can, theoretically, be used to create super-fast transistors. Graphene has a multitude of possible applications, but it has so far evaded the attempts of scientists to use it in the making of transistors.
According to Guy Le Lay, a materials scientist at Aix-Marseille University in France, “For logic applications, graphene is hopeless.” With graphene not living up to its immense promise, at least, not yet, researchers are now more interested in exploring the use of silicene in making super-fast transistors.
A major drawback to previous attempts researchers have made in creating such transistors is the instability of silicene. The material is unstable when exposed to air, though a research team from the University of Texas at the Cockrell School of Engineering might have hit upon a way to make the substance stable, albeit for a tantalizingly brief time of just a few minutes. But, it is a beginning, and through more experimentation, they might be able to increase the length of time in order to make the substance perfect for commercial purposes, like in cell phones and computers of the future.
The substance has many properties which would, apart from its instability, make it perfect to be uses in the creation of super-transistors. For instance, it is made from silicon, one of the most abundant materials around. Also, the material is incredibly thin, composed of a layer of silicon atoms that is only an atom thick. The icing on the cake is that the material is a great conductor of electricity, something which chip designers definitely favor in the material.
The drawback of the silicon-based material, its being so unstable when it comes into contact with air, has hindered its potential promise in making super-fast transistors up until recently. The substance has rarely been made at all, and the researchers at the University of Texas were the first ones to discover a method to make the substance into a transistor.
The method that the researchers used was outlined in a UoT press release. The silicene was created within a vacuum chamber. Within the chamber, silicon atoms were released in a hot vaporous state. The silicon atoms collected and condensed on a block of crystalline silver, forming a silicene sheet. Then, the sheet was covered and protected by an ultra thin layer of aluminium oxide, or alumina.
The researchers were then able to peel the thin film of silicene off of the silver block. They transferred the film to a substrate of oxidized silicon. The process of scraping off a little bit of the silver made the end product a strip of silicene with two electrodes exposed on either side of it.
The transistor was efficient, consuming a low amount of power, though it just lasted a few minutes. After a method is hit upon that will allow the substance to be more stable, researchers will still need to figure out how to create integrated circuits from the silicene transistors. Because of its silicon base, silicene can form the “band gaps,” that transistors require. Increasing the stability of silicene could lead to the production of faster computer chips that also are more efficient.
There is still a long way to go before the promise of silicene might be, one day, fully realized. For now, though, it is a material that is having its fifteen minutes in the spotlight, and talk about the many possible applications that silicene might have is making many people consider it as being the new wonder material on the block. Still, the material has come a long way, already, especially considering it was not even proven to exist until 2010. Sheets of the material were first condensed onto silver blocks in a vacuum tube in 2012. Silicene is now being considered as being a practical material to create super-fast transistors with, one day in the not-so-distant future.
Written By Douglas Cobb