“We have developed a new method to utilize low-cost, environmentally friendly materials from the commodity chemical industry to control the performance of organic semiconductors,” said Michael Chabinyc, associate professor of materials.
Organic semiconductors are electronic materials with conductive properties similar to the familiar silicon-based material used in devices such as photovoltaics and computer chips, but with carbon-based structures. Pioneered at UCSB by Nobel laureate Alan Heeger, professor of physics and materials engineering, and Fred Wudl, professor of chemistry and biochemistry and of materials, these semiconductors are useful for printable thin film electronics, such as light-emitting diodes, transistors, and solar cells.
Several challenges still exist in the emerging field of organic electronics, due in large part to their microstructure and crystallinity, the qualities of which can change with the method of their fabrication. The variations in these properties, in turn, can affect the materials’ electrical performance. While solution-based processes such as inkjet printing and blade coating can allow for inexpensive manufacturing, control over the microstructure must be maintained and at times the result is substantial variation in performance.
“The electrical properties of organic semiconductors depend critically on the way in which molecules pack together—the crystallinity. Gaining ways to control the crystallinity simply broadens the range of options for manufacturing,” Chabinyc said.
With the addition of minute amounts of nucleating agents, additives more commonly used in items like clear plastic drinking cups to maintain flexibility and to enhance their transparency, the researchers were able to demonstrate a method that offers more control over the formation of the organic semiconductors’ microstructures while at the same time increasing yield without sacrificing their performance. In addition to the sugar-based additive, the researchers tested another organic nucleating agent with a more complex structure.
Read more at: Phys.org