High-resolution Si 2p spectra obtained with 8 keV excitation energy measured using the HAXPES instrument
Hard X-Ray Photoelectron Spectroscopy at P22 is dedicated to study the electronic and atomic structure of surfaces, interfaces, and bulk materials. The beam line offers several end stations specialised for HAXPES, k-microscopy, HAXPEEM and high Pressure XPS. We serve users from divers research fields including physics, chemistry, materials science and engineering. Some of the main research topics are microelectronics and device characterization, solar cell and battery research, catalysis, new materials (e.g. for memory devices, spintronics) and fundamental solid state physics.
Interested users are strongly requested to contact the beamline staff before submitting a proposal for P22 to discuss the feasibility of any planned experiment. Please join the HAXPES mailing list for occasional updates here!
The beamline is designed for specific techniques making use of photoelectron emission excited by X-rays in an energy range from 2.4 keV up to about 15 keV. Hard X-ray photoelectron spectroscopy (HAXPES) has the ability to probe the detailed electronic structure of solid materials with significantly higher depth sensitivity than conventional photoelectron spectroscopy. This makes it ideally suited for the investigation of:
- buried interfaces of multi-layered functional materials
- as-grown samples without any need for prior in-situ surface treatment
- functional layers under e.g. a top electrode or gate
- catalytically active surfaces in reaction conditions
The beamline comprises a unique selection of techniques using specialized instruments built and operated in collaboration with external user groups. The main instrument is the established HAXPES hemisphere with the possibility for high throughput and operando spectroscopy. The second setup is a HAXPEEM instrument for spectro-microscopy applications utilizing the depth sensitivity in the keV energy range. The POLARIS setup for ambient pressure HAXPES for energy and catalysis in-operando enables studies of catalytic reactions at gas pressures of up to 2 bar. The Hard X-Ray Momentum Microscope (HarMoMic) gives access to the band structure of bulk samples and buried layers.
The X-ray source at P22 is a 2m long spectroscopy undulator in a high-β section of PETRA III. The key parameters are listed below:
| energy range | 2.4 - 15keV |
| max flux at sample |
about 2x1013 ph/s (Si(111) at 4-6 keV). |
| beam size | 10 x 10 µm2 to 3000 x 500 µm2 |
| polarisation | Horizontal (standard), vertical, cricular left, circular right |
| Photon energy resolution |
2.4 keV: ~200meV 3.4kev: <100meV 4.6keV: ~100meV 6.0keV: 40meV |
