Penn Engineers Develop First Transistors Made Entirely of Nanocrystal 'Inks'

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“The trick with working with solution-based materials is making sure that, when you add the second layer, it doesn’t wash off the first, and so on,” Kagan said. “We had to treat the surfaces of the nanocrystals, both when they’re first in solution and after they’re deposited, to make sure they have the right electrical properties and that they stick together in the configuration we want.”   

Because this entirely ink-based fabrication process works at lower temperatures than existing vacuum-based methods, the researchers were able to make several transistors on the same flexible plastic backing at the same time.  

“Making transistors over larger areas and at lower temperatures have been goals for an emerging class of technologies, when people think of the Internet of things, large area flexible electronics and wearable devices,” Kagan said. “We haven’t developed all of the necessary aspects so they could be printed yet, but because these materials are all solution-based, it demonstrates the promise of this materials class and sets the stage for additive manufacturing.”

Because this entirely ink-based fabrication process works at lower temperatures than existing vacuum-based methods, the researchers were able to make several transistors on the same flexible plastic backing at the same time.  

“Making transistors over larger areas and at lower temperatures have been goals for an emerging class of technologies, when people think of the Internet of things, large area flexible electronics and wearable devices,” Kagan said. “We haven’t developed all of the necessary aspects so they could be printed yet, but because these materials are all solution-based, it demonstrates the promise of this materials class and sets the stage for additive manufacturing.”

The research was supported primarily by the National Science Foundation through its Materials Research Science and Engineering Centers Award DMR-1120901 and its Chemical, Bioengineering, Environmental, and Transport Systems Award CBET-1236406, the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering Award DE-SC0002158, the Office of Naval Research Multidisciplinary University Research Initiative Award ONR-N00014-10-1-0942, the Basic Research Project of the Korea Institute of Geoscience and Mineral Resources funded by the Ministry of Science, ICT and Future Planning of Korea.