AP Distinguished Seminar - Development of High-performance p-type Semiconductors
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Date
23 Jan 2026
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Organiser
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Time
15:00 - 16:00
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Venue
CD620, 6/F, Wing CD, PolyU Map
Speaker
Prof. NOH Yong-Young
Summary
Developing high-mobility p-type semiconductors that can be grown using silicon-compatible processes at low temperatures, has remained challenging in the electronics community to integrate complementary electronics with the well-developed n-type counterparts. This presentation will discuss our recent progress in developing high-performance p-type semiconductors as channel materials for thin film transistors. For the first part of my talk, I present an amorphous p-type oxide semiconductor composed of selenium-alloyed tellurium in a tellurium sub-oxide matrix, demonstrating its utility in high-performance, stable p-channel TFTs, and complementary circuits. Theoretical analysis unveils a delocalised valence band from tellurium 5p bands with shallow acceptor states, enabling excess hole doping and transport. Selenium alloying suppresses hole concentrations and facilitates the p orbital connectivity, realizing high-performance p-channel TFTs with an average field-effect hole mobility of ~15 cm2 V-1 s-1 and on/off current ratios of 106~107, along with wafer-scale uniformity and long-term stabilities under bias stress and ambient aging. Next, I will present high-performance tin (Sn2+) halide perovskite based p-type transistors using cesium-tin-triiodide-based semiconducting layers. The optimized devices exhibit high field-effect hole mobilities of over 50 cm2 V−1 s−1, large current modulation greater than 108, and high operational stability and reproducibility. In addition, we explore triple A-cations of caesium-formamidinium-phenethylammonium to create high-quality cascaded Sn perovskite channel films. As such, the optimized TFTs show record hole mobilities of over 70 cm2 V−1 s−1 and on/off current ratios of over 108, comparable to the commercial low-temperature polysilicon technique level. In the last part, I would like to briefly introduce our recent halide perovskite transistors fabricated by thermal evaporation.
Keynote Speaker
Prof. NOH Yong-Young
Chair Professor
Department of Chemical Engineering
Pohang University of Science and Technology
Prof. NOH Yong-Young is the Namgo Chair Professor of the Department of Chemical Engineering of Pohang University of Science and Technology (POSTECH). He received his PhD degree in 2005 from GIST and then worked at the Cavendish Laboratory in Cambridge, UK, as a postdoctoral associate. Afterwards, he worked at ETRI as a senior researcher, as an assistant professor at Hanbat National University, and as an associate professor at Dongguk University. His research interest is developing novel semiconductors for field-effect transistors, photodetectors, and light-emitting diodes. He is a fellow of the Korean Academy of Science and Technology and the National Academy of Engineering of Korea.
