X-ray Photoelectron Spectroscopy (XPS)
Elemental Composition and Chemical States
X-RAY PHOTOELECTRON SPECTROSCOPY (XPS)
XPS analysis is a surface-sensitive analytical technique used to measure the material's elemental composition and chemical state. XPS determines the kinetic energy distribution of photoelectrons emitted because of monochromatic X-ray irradiation. The binding energy is calculated from the energy of the irradiating X-rays and the kinetic energy of the photoelectrons (Refer to Figure).
EBE = hν-EKE -Ф
Where hν is the X-ray energy, EKE is the kinetic energy of the emitted electron, and hν-EKE -Ф is a constant, the work function of the spectrometer.
PROS OF XPS ANALYSIS
- Surface analysis to determine the chemical composition of the sample
- Quantitative analysis identifies the variation in the oxidation states of the samples
- Measure all elements except Hydrogen (H) and Helium (H)
- Distinguish Phosphine (PH3) and Phosphate (PO43-) in phosphorous
- Depth profile analysis for elements less than 1 at%
CONS OF XPS ANALYSIS
- Limited to organic compounds
- Non-ideal for liquid and gases
- Limited analytical area of the sample
- Not suitable for bulk or layered thin films <1 at%
TECHNICAL SPECIFICATIONS OF XPS ANALYSIS
- Detects signal via emission of photoelectrons from the near-surface atoms
- The detection limit is 0.1 at%
- Can perform Imaging/Mapping
- Surface sensitivity < 10 nm
Curious to know more about using X-ray Photoelectron Spectroscopy (XPS)?