- A New Technology That Could Sweep the World — Made in KoreaLaying the groundwork for electronic circuits that recognize the human five sensesNext-generation display research speeding up realities like five-sense broadcasting
[Scientist of the Month] Professor Kim Seon-guk, Kyung Hee University
Developed a thin-film transistor using molybdenum disulfide
Overcame flexibility and mobility limits, the hurdles to commercialization 
- A schematic of the MoS2-based thin-film transistor. The thin-film transistor consists of a Drain, a Source, and a Gate (SiO2). The enlarged circle shows the atomic structure of molybdenum disulfide — MO is a molybdenum atom and S is a sulfur atom. /Provided by Professor Kim Seon-guk's research team
"The development of an electronic circuit that can transmit the five human senses — sight, touch, hearing, smell, and taste — is right in front of us. Before long we will be able to experience five-sense broadcasting."
Professor Kim Seon-guk of the Department of Electronic and Radio Engineering at Kyung Hee University, selected as January's Scientist of the Month — an award jointly organized by the Ministry of Education and Science Technology, the National Research Foundation of Korea, and the Seoul Economy Daily — explained, "The thin-film transistor we developed this time is based on a material called molybdenum disulfide (MoS2), and it overcomes the flexibility and mobility limits that had been hurdles to commercialization." Professor Kim added, "This research is significant in that it presents a new conceptual foundation for designing electronic circuits," and continued, "Going forward, I will push harder to secure original technology in unexplored fields from a creative viewpoint," as his award remarks.
Professor Kim's MoS2-based thin-film transistor, with its two-dimensional structure, is a new type of transistor with semiconductor-like properties.
Transparent, bendable displays, the kind you often see in movies, heavily rely on thin-film transistors (TFTs). Transistors made from materials developed so far have used silicon as the main material, and they have limits in mobility and flexibility. Mobility indicates how fast electrons flow inside a material; to serve as a semiconductor material, it usually has to be 30 cm2/V·sec or higher, but achieving that is not easy. On top of that, when the substrate of a plastic-based transistor is heated beyond 300 degrees, it bends and cracks. So, with mobility stuck around 30 cm2/V·sec and a tendency to crack easily at high temperatures, existing transistors had real commercialization limits.
The MoS2-based thin-film transistor Professor Kim developed shows a mobility of 150 cm2/V·sec — more than enough to be used as a semiconductor material — and the system runs below 100 degrees, so there is no chance of the substrate bending or cracking, because the high-temperature environment of 300 degrees or more is never reached. His research creates the opening to overcome mobility and flexibility, the very limits that had blocked transparent and flexible displays using existing thin-film transistors.
Thanks to this achievement, research aimed at replacing existing silicon transistors is expected to accelerate. MoS2 is attracting strong attention as a core element for the drive circuits of next-generation displays, thanks to its high transparency and high flexibility.
Research into chalcogenide-family materials with a two-dimensional structure like MoS2 has been ongoing globally only for about the past two years. Chalcogenide-family materials emerged as a new research field in 2011 as the next-generation graphene. For practical applications of this material, comprehensive research into MoS2's fabrication and properties is needed.
Professor Kim's research results are seen as opening a new field that will lead the next-generation display industry. Such foundational technology has enormous future value, since it can be applied to various optoelectronic devices and digital circuits.
Among the actively researched alternatives to silicon transistors are carbon nanotubes, nanowires, organic nanowires, and the widely known graphene.
Professor Kim is a rising researcher internationally recognized for developing next-generation thin-film transistors based on new 1D and 2D nanomaterials, as well as designing next-generation displays, memory, and five-sense-augmented electronic circuit designs using them, and carrying out research. Based on new semiconductor materials, he has done original research in next-generation electronic devices and circuit design, publishing 35 papers in SCI-indexed journals over the past five years. He has filed 14 domestic and international patents at the level of original technology, leading the field.
Academia and industry alike view 'MoS2, the next-generation 2D nano-semiconductor material' as the most notable new TFT material since graphene. Convergence research across physics, chemistry, materials engineering, and biotechnology around MoS2 is expected to form a new academic ecosystem.
Professor Kim's MoS2-based thin-film transistor was published in the August issue of Nature Communications, and featured as the cover paper of the November issue of Advanced Materials, a leading journal in the materials field.
Professor Kim Seon-guk of the Department of Electronic and Radio Engineering at Kyung Hee University, selected as January's Scientist of the Month — an award jointly organized by the Ministry of Education and Science Technology, the National Research Foundation of Korea, and the Seoul Economy Daily — explained, "The thin-film transistor we developed this time is based on a material called molybdenum disulfide (MoS2), and it overcomes the flexibility and mobility limits that had been hurdles to commercialization." Professor Kim added, "This research is significant in that it presents a new conceptual foundation for designing electronic circuits," and continued, "Going forward, I will push harder to secure original technology in unexplored fields from a creative viewpoint," as his award remarks.
Professor Kim's MoS2-based thin-film transistor, with its two-dimensional structure, is a new type of transistor with semiconductor-like properties.
Transparent, bendable displays, the kind you often see in movies, heavily rely on thin-film transistors (TFTs). Transistors made from materials developed so far have used silicon as the main material, and they have limits in mobility and flexibility. Mobility indicates how fast electrons flow inside a material; to serve as a semiconductor material, it usually has to be 30 cm2/V·sec or higher, but achieving that is not easy. On top of that, when the substrate of a plastic-based transistor is heated beyond 300 degrees, it bends and cracks. So, with mobility stuck around 30 cm2/V·sec and a tendency to crack easily at high temperatures, existing transistors had real commercialization limits.
The MoS2-based thin-film transistor Professor Kim developed shows a mobility of 150 cm2/V·sec — more than enough to be used as a semiconductor material — and the system runs below 100 degrees, so there is no chance of the substrate bending or cracking, because the high-temperature environment of 300 degrees or more is never reached. His research creates the opening to overcome mobility and flexibility, the very limits that had blocked transparent and flexible displays using existing thin-film transistors.
Thanks to this achievement, research aimed at replacing existing silicon transistors is expected to accelerate. MoS2 is attracting strong attention as a core element for the drive circuits of next-generation displays, thanks to its high transparency and high flexibility.
Research into chalcogenide-family materials with a two-dimensional structure like MoS2 has been ongoing globally only for about the past two years. Chalcogenide-family materials emerged as a new research field in 2011 as the next-generation graphene. For practical applications of this material, comprehensive research into MoS2's fabrication and properties is needed.
Professor Kim's research results are seen as opening a new field that will lead the next-generation display industry. Such foundational technology has enormous future value, since it can be applied to various optoelectronic devices and digital circuits.
Among the actively researched alternatives to silicon transistors are carbon nanotubes, nanowires, organic nanowires, and the widely known graphene.
Professor Kim is a rising researcher internationally recognized for developing next-generation thin-film transistors based on new 1D and 2D nanomaterials, as well as designing next-generation displays, memory, and five-sense-augmented electronic circuit designs using them, and carrying out research. Based on new semiconductor materials, he has done original research in next-generation electronic devices and circuit design, publishing 35 papers in SCI-indexed journals over the past five years. He has filed 14 domestic and international patents at the level of original technology, leading the field.
Academia and industry alike view 'MoS2, the next-generation 2D nano-semiconductor material' as the most notable new TFT material since graphene. Convergence research across physics, chemistry, materials engineering, and biotechnology around MoS2 is expected to form a new academic ecosystem.
Professor Kim's MoS2-based thin-film transistor was published in the August issue of Nature Communications, and featured as the cover paper of the November issue of Advanced Materials, a leading journal in the materials field.
