MSE Colloquium: Jong-Heun Lee, Gas Sensors Using p-type Oxide Semiconductors: Opportunities and Challenges

Graduate Program Director, Department of Materials Science and Engineering, Korea University

Abstract

Oxide semiconductors are promising material platforms for highly sensitive, cost-effective, and reliable gas sensors. Since 1960s, the n-type oxide semiconductors such as SnO₂, ZnO, TiO₂, In₂O₃, Fe₂O₃, and WO₃ have been intensively studied to detect trace concentrations of harmful, toxic and explosive gases. In contrast, the p-type oxide semiconductors such as NiO, CuO, Cr₂O₃, and Mn₃O₄ with different receptor functions, conduction paths, and gas sensing mechanisms, have been barely investigated as chemoresistive materials because of their relatively low gas responses. Moreover, the selective detection of a specific gas using oxide semiconductors remains a challenging issue for the practical applications. In this contribution, new strategies to design high-performance p-type oxide semiconductors with ultrahigh sensitivity and ultrahigh selectivity have been suggested, which include the control of charge carrier concentration by aliovalent doping and the promotion of sensing reaction toward a specific gas by loading or doping catalysts. The p-type oxide semiconductors with distinctive catalytic activity and electrical property are valuable materials to design gas sensors with new and novel functionalities.

Bio

Prof. Jong-Heun Lee received his BS, MS, and PhD degrees from Department of Inorganic Materials and Engineering, Seoul National University, Seoul, Korea in 1987, 1989, and 1993, respectively. Between 1993 and 1999, as a senior researcher, he developed automotive air-fuel-ratio sensors at the Samsung Advanced Institute of Technology. He was a Science and Technology Agency of Japan (STA) fellow at the National Institute for Research in Inorganic Materials (currently NIMS, Tsukuba, Japan) from 1999 to 2000 and a research professor at Seoul National University from 2000 to 2003. Dr. Lee has been a professor at the Department of Materials Science and Engineering, Korea University since 2003. He is currently a director of graduate program in the Department of Materials Science and Engineering, Korea University. He has actively participated in his academic societies as journal editors of Sensors and Actuators B: Chemical (SCI, associate editor) and Science of Advanced Materials (SCIE, editor), international advisory board member in Analytical and Bioanalytical Chemistry (SCI), conference organizers and so on. He is a junior member of the Korean Academy of Science and Technology. In 2014, he has been selected as ‘Highly Cited Researchers’ by Thomson Reuters for ranking in the top 1% most cited papers. He has won the awards including ‘100 future-leading technologies and their developers’ (2013) by National Academy of Engineering of Korea, ‘the patent of year’ (Ji-Seok-Young Prize, 2001) from Korean Intellectual Property Office and ‘Granite Tower Best Teaching Awards’ (2008 and 2009) from Korea University. He published 220 peer-reviewed papers (H-index: 35, total citation: 4,388 by web of science) and holds 40 domestic and international patents.