3D Integration of organic printed transistors and circuits
Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang, South Korea
The direct printing of organic thin-film transistors (TFTs) on plastic foil has received considerable attention for the realization of low-cost and flexible intelligent circuits and systems. However, despite the significant enhancements in material properties such as carrier mobility, few attempts have been made to print organic integrated circuits (ICs). The relatively large size of printed features (typically 10 um – 100 um) have limited the implementation of organic ICs with reasonable transistor densities. To overcome the limitation, we introduce three-dimensional (3D) integration of inkjet-printed organic transistors and circuits. We fabricated a p-type organic field-effect transistor that is inkjet-printed on top of an n-type organic field-effect transistor with a shared gate joining the two transistors. Based on the common-gate transistor-on-transistor structure, a complementary inverter array is fabricated with a high static noise margin (SNM) and reliable characteristics. We have further developed 3D integration of a dual-gate NAND technology fabricated by printing technique with a demonstration of flexible logic circuits. The vertical stacking of independent-gate controlled dual gate transistors offers enhanced on-current, lowered sub-threshold swing, increased device stability and density. The present study fulfills the essential requirements for the fabrication of organic printed complex ICs, and the findings can be applied to realize more complex digital/analogue ICs and intelligent devices.
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Dr. Sungjune Jung is an associate professor of Creative IT Engineering in Pohang University of Science and Technology (POSTECH). He is also affiliated in Department of Chemical Engineering, Electrical Engineering, Mechanical Engineering, Integrative Bioscience and Biotechnology (IBB) and School of Interdisciplinary bioscience and bioengineering (IBIO). He received his PhD degree from the University of Cambridge in 2007 and subsequently joined the Cavendish Laboratory (Physics Department) of University of Cambridge. Before his PhD, he worked for Samsung Electronics, Digital Printing Division for 3 years. He has been leading the Bio-Printing and Printed Electronics Laboratory since he joined POSTECH in 2013. His research focuses on design and fabrication of printed transistors and circuits, biosensor platforms, organ-on-a-chip and high-throughput drug screening based on printing process.
Pohang University of Science and Technology was founded with the purpose of contributing to the nation and humanity by conducting in-depth science and engineering research on the profound theories and wide range of applications essential to the advancement of Korea and the world, training a select pool of talented students to become future global leaders with both knowledge and honorable character through high-quality education and translating research outcomes into real-world applications realized through close collaboration with industry, academia and research institutions. . In 2012, POSTECH was ranked first in the Times Higher Education’s “100 under 50” which lists the top 100 universities in the world under 50 years old.