Researchers from two different universities have teamed up to create the "world's fastest thin-film organic transistors" that are able to "operate more than five times faster than previous examples of this experimental technology." The research has been published in the Jan. 8 edition of Nature Communications.
The team at Stanford University was led by chemical engineering professor Zhenan Bao, while the University of Nebraska-Lincoln was led by Jinsong Huang, an assistant professor of mechanical and materials engineering.
The team made some important changes in the process of how thin-film organic transistors were made. The previous process required dropping a solution onto a spinning glass platter to deposit a thin coating of materials on the platter. In this project, the researchers spun their platter faster than usual and coated just a small, postage-stamp sized section of the platter. The researchers dubbed this method, "off-center spin coating."
In a statement that reported their findings, the researchers said that these innovations served to help deposit a denser concentration of the organic molecules into more regular alignments, resulting in greater carrier mobility, which measures how quickly electrical charges travel through the transistor.
"These innovations had the effect of depositing a denser concentration of the organic molecules into a more regular alignment. The result was a great improvement in carrier mobility, which measures how quickly electrical charges travel through the transistor," the statement said.
The researchers said that they are unable to control certain factors, such as the alignment of organic materials in their transistors, and uniform carrier mobility. Nevertheless, the team said that the off-center spin coating method created thin-film transistors capable of performing faster, and in a way that was "comparable to the performance of the polysilicon materials used in today's high-end electronics."
The process also rendered the organic transistors almost totally see-through, which the scientists say is "90 percent transparent to the naked eye." They also predict that their method could "lead to the development of inexpensive, high-performance electronics built on transparent substrates such as glass and, eventually, clear and flexible plastics."
The research was funded by the U.S. Defense Advanced Research Projects Agency (DARPA), the Air Force Office of Scientific Research and the National Science Foundation.
