Dr. Po-Yang PengTaiwan
National Synchrotron Radiation Research Center (NSRRC)
| 2024 to present | | Assistant Research Scientist, v |
| 2019 - 2024 | | Scientist, FlowVIEW Tek |
| 2015 - 2019 | | Postdoctoral, NSRRC |
| 2010 - 2015 | | Ph.D. in Chemical Engineering, National Taipei University of Technology |
Hard X-ray Photoelectron Spectroscopy (HAXPES),
X-ray Absorption Spectroscopy,
Electrochemistry,
In-situ / Operando Techniques Analysis Techniques,
Combined XAS and TXPES at the Tender X-ray Beamline TPS 32A of Taiwan Photon Source
TBA TBA
Applications of Synchrotron Radiation in Catalysis/TBA
The tender X-ray absorption spectroscopy beamline (TXAS, TPS 32A) at the Taiwan Photon Source (TPS), based on a bending-magnet source, covers a photon energy range from 1.7 to 11 keV and delivers a focused beam spot of approximately 0.5 × 1 mm². This beamline supports both X-ray absorption spectroscopy (XAS) and tender X-ray photoelectron spectroscopy (TXPES) measurements. An automated sample exchange system and comprehensive data-recording infrastructure have been implemented to significantly improve experimental throughput and user-friendly.
Recent upgrades to the XAS endstations enhance experimental flexibility, enabling both standard measurements and in situ XAS experiments. At the beam focal point, the endstation is equipped with a wide-angle (±15°) photoelectron analyzer installed in an ultrahigh-vacuum (UHV) chamber.
Owing to its interface-sensitive nature and probing depth of approximately 5–15 nm, TXPES is particularly well suited for investigations of thin films, multilayer systems, and buried interface chemical states, such as heterostructure interfaces within nanoshell architectures. For intermediate atomic number (Z) elements, including Si, P, S, Cl, etc., and 3d transition metals, tender X-rays exhibit significantly higher photoelectric absorption cross-sections than hard X-rays (>5 keV). Compared with high-energy, high-flux hard X-ray photoelectron spectroscopy (HAXPES), TXPES offers higher signal intensity, improved energy efficiency, superior signal-to-noise ratios, and substantially reduced radiation damage. These advantages facilitate long-duration measurements while preserving the intrinsic properties of the investigated materials.
In addition, XAS measurements in this chamber can be conducted in both partial electron yield (EY) and fluorescence yield (FY) modes using an integrated region-of-interest (ROI) detection scheme at the same measurement position. The combined application of XAS and TXPES enables complementary access to unoccupied and occupied electronic states, respectively, providing a comprehensive picture of the electronic structure around the Femi level (EF). TPS 32A provides critical electronic and chemical structure information for diverse research fields, including physics, chemistry, materials science, and biology.