Research Professor, Department of Printed Electronics Engineering, Sunchon National University
Limitless-length R2R gravure printed flexible carbon nanotube-based TFT active matrix and its electrophoretic display
Junfeng Sun (1,*), Hyejin Park (1), Ashish Sapkota(1), Prince Wesley (1) , Younsu Jung (2) and Gyoujin Cho
(1) Department of Printed Electronics Engineering, Sunchon National University, 255 Jungang-ro, Jeollanam-do, 57922, Rep. of Korea
(2) Department of Materials Science and Engineering Tokyo Institute of Technology
Nagatsuta-cho, Midori-ku, Yokohama 226-8503, Japan
For having competiveness over Si based devices, printed TFT-based electronics should prove its superior scalability in mass production of flexible large area devices through a roll-to-roll (R2R) printing method as a typical advanced manufacturing system, because the flexible large area TFT-based devices are hard to manufacture using the current photolithography and vacuum deposition technologies.
In this study, R2R gravure printing system with the superior advantages of cost effectivity and scalability was employed for printing limitless-length and roll-able thin film transistor -active matrix (TFT-AM), the resolution of printed TFT-AM was scaled up from 10 PPI to 40 PPI, the printed 10 PPI resolution TFT-AM by the printing speed of 6 m/min to attain a 96.5% device yield, an average mobility of 0.02±0.005 cm2/Vs, average on-off current ratio of 103.5±0.6, and a threshold voltage (Vth) variation of ±5.6 % , for the printed 40 PPI resolution TFT-AM, with the same printing speed, device yield of 95% with an average mobility of 0.23±0.12 cm2/Vs, average on-off current ratio of 104.1, and a Vth variation of ±13% was also attained. At last a electrophoretic display signage with a resolution of 10 PPI was demonstrated based on the fully R2R gravure printed carbon nanotube limitless-length TFT active matrix.
Dr. Junfeng Sun received his Ph.D degree from Department of Printed Electronics of Sunchon National University of Korea, 2017. At current his is a research professor in the world wide famous flexible & printed electronics research team （Prof. Gyoujin Cho’s team of Sunchon National University）, Dr. Sun’s research interests including flexible, large area and low-cost electronic devices based on printed electronics technology, such as, the ink materials and process development of fully R2R gravure printed TFT device and their display and sensor applications. Recently, he is developing fully R2R gravure printed TFT active matrix for large area digital signage and R2R gravure printed NFC tags as a platform for RF e-sensor based smart packaging.
Possessing the leading technology in NT-PT printign fields, Sunchon National University (SCNU) has selected and been supporting printed electronics as a univeristy specialization field. As a fruit of this effot, printed electonics stated the WCU porgram in 2008 and extended the program to 2020 via BK21PLUS program.