09 Sep 2004
UK firm develops a new material for organic displays which it says is far less toxic then Alq3.
A UK start-up claims to have developed a suite of highly efficient, environmentally-friendly materials for making organic light emitting displays (OLEDs). The innovation means that Elam-t's technology may soon be found in small flat panel displays found in mobile phones and other portable electronics.
The spin-off from London South Bank University, has spent the past 5 years developing all then ingredients needed to make bright, long-lasting OLEDs. Its range of materials now includes emitters (fluorescent, phosphorescent and ion-fluorescent) of red, green and blue light as well as transparent buffer materials and electron transport layers. As a result it now has around 60 patents in the field.
Perhaps, most significantly Elam-t has invented an electron transport layer called E246 that it says is a highly attractive alternative to the Alq3 [aluminium tris(8-hydroxyquinoline)] used by other firms.
According to Professor Kathirgamanathan, Elam-t's chief technology officer, E246 does not only have treble the lifetime and better color co-ordinates than Alq3 but is also much less toxic.
"Many display firms, especially in Japan, are concerned about using Alq3 because of worries over environmental pollution," said Kathirgamanathan. "We have the solution to those worries."
Elam-t has also developed a buffer layer for the display substrate that can be deposited at a much lower temperature than conventional materials. "All OLED makers are currently using a buffer layer that needs to be processed at 430 °C which risks damage to the ITO or polysilicon substrate," said Kathirgamanathan. "Our buffer evaporates at 130 °C less than that."
As for making money from these innovations, Kathirgamanathan says that Elam-t will remain the sole maker of its materials and then license the right to use them to display makers. He says that its recent success in Japan is a critical turning point in the company.