DEC. 5–BOSTON, Mass.–A potential alternative to silicon transistors, printed plastic electronics, could dramatically lower costs, usher in a new generation of products and eliminate the need for cleanrooms.
Beng Ong, a research fellow at Xerox Corp.’s Research Centre of Canada, believes a new material developed by his team of scientists will also bring the world one step closer to portable, poster-like television screens and monitors made of a single sheet of flexible plastic.
“One of the main cost advantages of printed plastic transistors is that they will not need specialized, costly fabrication facilities and procedures, while silicon transistors require ultra-clean room environments, high-temperature vacuum systems, and complex, photolithographic processes,” said Ong, an inventor who holds more than 110 U.S. patents and who manages the printed organic electronics group at XRCC in Mississauga, Ontario.
Ong described the design and synthesis of breakthrough semiconducting organic polymers that show promise for printing electronic patterns on a plastic substrate – the plastic equivalent of etching circuits on silicon wafers – in a talk presented at the Materials Research Society’s fall conference here.
His experimental materials possess the outstanding electrical properties that would be necessary for printing plastic circuits. But in contrast to other materials that degrade quickly when exposed to oxygen, the Xerox materials are stable in air, a requisite for low-cost manufacturing under ambient conditions. No one else has been able to achieve this combination in a polymer material.
Printed plastic transistors augur an inexpensive, easy-to-manufacture alternative to silicon electronics, which are difficult to fabricate and can cost up to $10,000 per square meter. Projected applications range from identification tags on merchandise to electric paper displays.
Designing performance-specific materials and developing robust printing processes for device manufacturing are key challenges in realizing this vision; both are areas where Xerox has expertise. Its scientists have a long history of productive research in conductive organic materials, printing technologies, and device and systems technology – expertise at the heart of Xerox printing and copying products.
Under a National Institute of Standards and Technology grant, scientists from XRCC and the Palo Alto Research Center, a subsidiary of Xerox in Palo Alto, Calif., are collaborating with teams at Motorola Labs and Dow Chemical to “develop novel organic electronic materials and processing technologies … to enable the fabrication of large-area electronic devices, such as displays, using relatively inexpensive printing technologies in lieu of semiconductor lithography.”
Ong and his group developed the breakthrough material by first understanding the polymer structural features responsible for limitations in existing materials, and by then developing design rules to get around those limitations. The materials were evaluated in simple devices at XRCC, with further testing and experimental printing at PARC and select electronics firms around the world.