High-resolution transmission electron energy-loss spectroscopy was used to explore the electronic structure of a reconstructed defect in the interior of crystals. In spite of the electronic and optical inactivity of the defects, the L2,3 near-edge structure became sharp within a narrow energy range (less than 1eV) whenever an electron probe was located at the defects. An analysis which was based upon ab initio computations suggested that the sharpened near-edge arose from an odd-membered atomic ring in the defects.

Detection of inactive defects in crystalline silicon using high-resolution transmission electron energy-loss spectroscopy H.Kohno, T.Mabuchi, S.Takeda, M.Kohyama, M.Terauchi, M.Tanaka: Physical Review B, 1998, 58[16], 10338-42