Making the angle change between the sensor and the standard on surface from 0° to 75°, the analysis depth can change from 10 nm to 3 nm. When the electrons sensor is standard, the analysis depth is about 10 nm.
Xps peak identification free#
The analysis depth is function of the inelastic mean free paths of photo-electrons in the material. The identification of elements present on the surface of a material is made of photoelectrical peaks which appear on the spectrum. XPS spectra represent the intensity (number of photoelectrons) according to their binding energy. The kinetic energy of photoelectrons emitted allows to determinate their binding energy (E B = hν– E C), characterised for emitter atoms and the nature of chemical shapes. If their kinetic energy is sufficient, they are extracted from the material and go through emptiness. Propulsed in the material, they travel a certain distance, function of that kinetic energy and of the material. During the interaction of photons with the atom, a part of their energy is used to break the link, its binding energy (E B) the rest is transfered to the electron with kinetic energy (E C). The sample is irradiated with X-Rays of hν energy causing the ionisation of its atoms through photoelectrical effect.