Kai Siegbahn Laboratory

X-ray photoelectron spectroscopy is a powerful tool to study electronic levels in matter- and how these levels shifts depending on the chemical environment, the so called chemical shift. The method is based on the photoelectric effect and was developed at Uppsala University, starting in the 1950’s, by a group led by Kai Siegbahn. The method is surface sensitive (a few nanometers), but by increasing the x-ray energy to the tender or hard x-ray regime the information depth becomes longer (tens of nanometers). This length scale is critical to investigate buried interfaces and the chemical evolution of those that constitute many functional parts of modern devices built up from modern materials.

The heart of this laboratory is a combined XPS/HAXPES instrument with monochromatic Al Kα (1.49 keV) and Ga Kα (9.25 keV) X-ray sources and a hemispherical electron analyzer. Solid samples, both conducting and non-conducting, can be measured under ultrahigh vacuum (5e-10 mbar) conditions. The instrument capabilities include cooling to liquid nitrogen temperatures and heating to 600°C. A four-probe sample connector allows measurements during applied potential or current in situ. A connected glove box allows sample transfers in inert atmosphere.

Planned development includes a chamber for sample preparation such as cleaning, deposition, dosing and LEED, as well as possibilities for long-term storage of samples in vacuum.