REELS is a surface analysis technique in which a surface is bombarded with an electron beam (typically ≤ 1 keV) and the energy distribution of the reflected electrons is measured. [1]
The energy distribution contains features whihc correspond to discrete losses of energy of the reflected electrons due to excited atomic states, core and valence band transitions, material bandgaps etc. It also provides information on hydrogen content (which XPS cannot do) and the type and geometric structure of compounds at the sample surface.
Uses of REELS
REELS can be used for many applicaitons, including:
- Semiconductor band gap measurement
- Electronic and bonding state analysis on the surface
- Determination of relative hydrogen content in materials
- Discrimination of sp2/sp3 bonds of carbon
- Evidence of aromaticity and conjugation in organic materials
References
[1] J.L. Erskine, Electron Energy Loss Spectroscopy in Analysis of Surfaces. Read online at https://doi.org/10.1002/9780470027318.a2505