Scientists at the University of Oxford have found that a material used to store data on DVDs can be used to make ultra-thin displays.
Harish Bhaskaran and Peiman Hosseini had initially wondered whether they could use it to make monochrome displays, like on e-ink readers, but found that it could produce many colours at once.
The material is the alloy germanium-antimony-tellurium (or GST for short). GST comes amorphous and disordered (at the molecular level – I know, I thought I finally found a friend). Shoot a laser beam and it changes phase and crystalises. Such phase changes on the backs of DVDs are used to store binary data.
But if you’ve ever looked and twirled the back of a DVD for a few seconds, (or minutes, or hours, days, weeks – don’t worry this is a safe space to admit it) then you could infer that these phase changes also change their colour.
Recycling done right
A layer of GST merely a few nanometres thick is sandwiched between sheets of a transparent conductor: indium tin oxide. Shine a laser beam here and the colour change mentioned before is harnessed. It’s still binary, but varying thicknesses of GST produce varying colour binaries.
The result is a possible ultra-thin, flexible, full-colour display that you could hope to see on wearable computers such as Google Glass. One must still hope, since there’s rather significant hurdles to overcome still. Like getting our DVD-twirling addicts off this, right? Hello?
Bhaskaran and Hosseini will have to figure out how the material could be transformed into a working display of moving images. Pixels in a display need to be able to produce a range of hues and GST sheets would need to be stacked. The logistics of it have yet to be puzzled. There’s also a strange problem where not all GST changes phase at once, which may create odd colour mixtures in an actual display.
For now, the team has been tasked and backed by Oxford to create a working GST display, so we may see some solutions soon enough.