Electronic Aspects of Oxygen Vacancy in Metal Oxides: X-ray Spectroscopic Investigation by Professor Deok-Yong Cho

23 Jan 2026 02.00 PM - 03.00 PM NTU Lecture Theatre 4 (NS4-02-34) Alumni, Current Students

Tan Chin Tuan Exchange Fellowship Lecture Hosted by Prof Lam Yeng Ming

Abstract

Scrutinizing the electronic structure of oxygen-deficient metal oxides has been a long-standing quest for electronic materials engineering. X-ray spectroscopy is one of the good options to characterize the oxygen-vacancy-influenced electronic structure in nanomaterials, for it is an element-specific probe having a nanometer-scale probing depth. However, it is always challenging to answer quantitatively how much the electronic structure (particularly near the Fermi level) changed per oxygen vacancy, because it is in principle impossible to measure the signals from the void (the oxygen vacancy). In this talk, I would like to share how we, negative-minded X-ray spectroscopists, manage to estimate the oxygen vacancy effects from the signals of the remaining atoms (either phenomenologically or being aided by first principle calculations, etc.) with cases of 3 representative X-ray spectroscopies; X-ray photoelectron spectroscopy (XPS) - a very often employed tool, X-ray absorption spectroscopy (XAS) – a bit rare tool, and lastly, resonant inelastic x-ray scattering (RIXS) – quite rare tool.

Biography


Deok-Yong Cho
Tan Chin Tuan Engineering Fellow at NTU
Professor, Department of Physics, Jeonbuk National University

Prof. Deok-Yong Cho received his doctoral degree in department of physics, Seoul National University (SNU) in 2007 with expertise in photoelectron spectroscopy. After post-doctoral + research professorship in the fields of physics and materials science in SNU, Sungkyunkwan Univ. and RWTH Aachen University, he joined professorship in department of physics, Jeonbuk National University in 2014. Throughout his career, he has studied the structural and electronic properties of various functional materials mostly using synchrotron X-ray spectroscopies. He is now keeping persistent collaboration networks with materials groups including Prof. Kwan Wee Tan’sand Prof. Yeng Ming Lam’s in MSE@NTU but also with many synchrotron groups worldwide.

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