Scientists from three UK universities have found a way to fine-tune the electrical conductivity of glass, which could finally pave the way for optical light-based computers that harness the power and speed of light to transfer data.
Researchers working together from the University of Surrey, the University of Southampton and Cambridge University used a technique known as "ion doping" on amorphous chalcogenides, a type of material made from glass that is widely used in CD and DVD solid-state memory technology.
Their research, entitled "n-type chalcogenides by ion implantation", is published in the latest issue of the journal Nature Communications.
"The challenge is to find a single material that can effectively use and control light to carry information around a computer," said Richard Curry, the current study's lead investigator and a physicist at University of Surrey.
"Much like how the web uses light to deliver information, we want to use light to both deliver and process computer data."
Several computing functions in one material
The ion doping technique was able to accommodate several different computing functions into one all-optical system by fine-tuning the electrical conductivity of the material, which has never been possible before.
Electrons are currently used by computers to transfer information and process applications, whereas data sources like the internet rely solely on optical systems to transfer information.
Optical fibres are able to send information requested from any computer around the world at the speed of light, but unfortunately, once the signals reach a computer, they have to be converted to electrical signals, thus slowing down the processing and transfer of information.
"This has eluded researchers for decades, but now we have now shown how a widely used glass can be manipulated to conduct negative electrons, as well as positive charges, creating what are known as 'pn-junction' devices," said Curry.
"This should enable the material to act as a light source, a light guide and a light detector – something that can carry and interpret optical information. In doing so, this could transform the computers of tomorrow, allowing them to effectively process information at much faster speeds."
Until now, semiconductors have been manufactured by using doping agents at very high temperatures that give materials a certain conductivity property as needed by changing the electron landscape of a material.
Creating pn-junction devices
The amorphous chalcogenides glass material has some very useful properties, including being great for conducting light across a wide range of bandwidths and enabling electron beams to be used to control the optical refraction of the material.
However, as the material is a positive charge (p-type) conductor, it resists interfacing with negative electron (n-type) conductors.
By making it possible for both negative electrons and positive charges to be conducted on a single material while only using a small amount of doping agent, the scientists have created a material that is cheaper to produce, thermally stable, highly refractive and requires a very small amount of electronic current to maintain optical information.
The researchers expect their new material to be integrated into computers with the next 10 years, and before that, they predict that amorphous chalcogenides will be used to create a next-gen computer memory technology called Chalcogenide RAM (CRAM) or phase-change memory (PRAM).
CRAM enables such high data transfer speeds that it has the potential to trump flash memory a thousand times over, and the technology is currently being researched by the likes of Intel, BAE Systems, Samsung, STMicroelectronics, IBM, Numonyx and Micron.