Dr. Andrew Yost will present his colloquium topic, “Hard X-ray Photoelectron Spectroscopy (HAXPES) in Material Development.” in-person.

Abstract: X-ray photoelectron spectroscopy is a powerful method to investigate the chemistry and physics of surfaces and buried interfaces which are critical for batteries, solar cells, etc. Hard X-rays have been increasingly useful in this field due to the higher photon energies and significantly increased information depth. Scienta Omicron’s HAXPES Lab uses a monochromatic Ga Ka metal jet source, enabling artefact-free investigations with superior information depth. Combined with a hemispherical electron analyzer with a ±30 degree acceptance angle, investigation of buried interfaces, operando devices and real world samples becomes easily achievable.

This presentation will give an overview of HAXPES applications with a focus on buried interfaces in electronic devices and the light source that enables such studies. For example, Nanoparticles typically consist of a core surrounded by a protective shell, e.g. passivation layer in quantum dots for optoelectronics and bioimaging. The shell thickness and chemical composition highly influence the material properties. Herein, a series of PTFE nanoparticles with PMMA shell was investigated (nominal shell thicknesses between 4.5 and 35.5 nm). The core material was detected even for particles with greatest shell thickness using Ga K? HAXPES.