absorption edge (rus. край полосы поглощения) — energy of electromagnetic radiation, above which there is a sharp increase in absorption of electromagnetic radiation by a substance.

Description

The increase in absorption is due to the fact that the energy of quanta of electromagnetic radiation becomes sufficient for the transfer of electrons, interacting with the quanta, into the excited state. Typical examples of spectra, containing absorption edges, are:

1) X-ray absorption spectra (Fig.) in the region where the electrons are dislodged from inner shells of atoms;

2) absorption spectra of semiconductors in the spectral region, whose energy is close to the energy of electron transition from the valence band into the conduction band, i.e. close to the bandgap (see blue shift).

Illustrations

X-ray absorption spectrum of CuAsSe2 compound at the edges of absorption of As and S
X-ray absorption spectrum of CuAsSe2 compound at the edges of absorption of As and Se [1].

Authors

  • Veresov Alexander G.
  • Tolkachev Nikolay N.

Source

  1. Fetisov, G.V. Synchrotron radiation. Methods for studying the structure of substances // Moscow: Fizmatlit, 2007. - 672 p.

Contact us