More flexible than a Romanian gymnast
Stanford and Harvard boffins have emerged from their smoke filled labs with faster organic semiconductors for flexible displays. According to a Stanford University press release, they have created a new material for high-speed organic semiconductors with a new manufacturing method that can take years off the development time line.
Last modified on Friday, 19 August 2011 09:45
The display world is jolly excited about organic semiconductors but they haven’t yet reached the speeds needed to drive high definition displays. This has forced them to use inorganic materials such as silicon, which are fast and durable but don’t bend. The new organic electronic material has also taken ages to make because boffins had to brew up large numbers of candidate materials and then test them.
The Stanford boffins decided to try a computational predictive approach to substantially narrow the field of candidates before expending the time and energy to make any of them. Anatoliy Sokolov, a postdoctoral researcher in chemical engineering at Stanford who worked on synthesizing the material, said that synthesizing some of these compounds can take years.
Sokolov used a material known as DNTT, which had already been shown to be a good organic semiconductor. They looked at different compounds possessing chemical and electrical properties that seemed likely to enhance the parent material’s performance if they were attached.
After they whittled it down to a short list of seven promising candidates the Harvard team predicted that two of the seven candidates would most readily accept a charge. They calculated that one of those two was markedly faster in passing that charge from molecule to molecule, so that became their choice. From their analysis, they worked out the new material to be about twice as fast as its parent.
Sokolov said it took about a year and a half to perfect the synthesis of the new compound and make enough of it for testing. “Our final yield from what we produced was something like 3 percent usable material and then we still had to purify it.”
But what was important was that when the team members tested the final product, their predictions were borne out and the modified material doubled the speed of the parent material. Apparently their new material is more than 30 times faster than the amorphous silicon currently used for liquid crystal displays in products such as flat panel televisions and computer monitors.
Normally it would have taken several years to both synthesize and characterize all the seven candidate compounds. With this approach, the boffins could focus on the most promising candidate with the best performance, as predicted by theory.