Abstract
Advances in semiconductor devices during last few decades enable us to improve the electronic device performance by minimizing the device dimension. However, further development of these systems to transparent, flexible, and stretchable soft electronics encounters scientific and technological limits and forces us to explore better alternatives. Low dimensional carbon allotropes such as carbon nanotube (CNT) and graphene exhibit superior electronic, optoelectronic, and mechanical properties compared to the conventional semiconductors.
In this talk, the speaker will review the recent progresses of carbon nanotubes and graphene researches in electronic applications and discuss drawbacks and bottleneck technologies, and further compare their electronic properties and electric device performances. A particular focus is given on the comparison of the characteristics in transparent conducting films (transparency and sheet resistance) and field-effect transistors (FETs) (device types, ambipolarity, mobility, doping strategy, FET-performance, logic and memory operations).
In particular, due to high conductivity but poor on/off ratio of graphene, graphene cannot be used for channel material in its current technology. The speaker and his research group therefore used graphene as an electrode material for source, drain, and gate and CNTs as a channel materials. This provides high performance with low hysteresis and moreover excellent flexibility and transmittance are obtained.
Finally, the performance of devices that combine graphene and CNTs is also highlighted for stretchable soft electronics. Some efforts on realizing stretchable electronics combining graphene and CNTs together with wrinkled gate oxides will be provided.
About the speaker
Prof Young Hee Lee received his PhD in Physics from Kent State University in 1986. He was faculty of Physics at Chonbuk National University from 1986 to 2001. He joined Sungkyunkwan University in 2001, and is currently Director of Center for Integrated Nanostructure Physics, and Professor of Energy Science and of Physics.
Prof Lee’s researches focus on understanding the fundamental properties of nanostructures in 0D, 1D and 2D and their hybrid heterostructures, design and synthesis of various heterostructures to implement unique physical and chemical properties. His research covers carrier dynamics, carrier multiplication phenomena, hot carrier solar cell, thermoelectrics, quantum mechanical tunneling phenomena, and nanocarbon-based soft electronics. His pioneering works on synthesis and engineering of electronic and atomic structures of carbon nanotubes and grapheme, other 2D materials and their applications to field emission displays, electronic devices, and energy harvesting have led not only nanoscience but also nanotechnology industry in Korea. He has published more than 380 scientific papers in international journals and his total citation number exceeds over 17,000 times with h-index of 59.
Prof Lee received numerous awards including the Science Award from the Korean Physical Society, Lee Hsun Research Award from the Chinese Academy of Sciences and the Presidential Award in Science and Education, etc. He was also nominated as a National Scholar by the Ministry of Education in Korea. He is a Fellow of the Korean Academy of Science and Technology.
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