We have applied high-resolution transmission electron energy-loss spectroscopy to explore the electronic structure of a reconstructed defect in the interior of Si crystal. Despite the electronic and optical inactivity of the defects, the $L_{2,3}$ near-edge structure becomes sharp within the narrow energy range (less than 1 eV) whenever an electron probe locates on the defects. Our analysis based on ab initio computations has suggested that the sharpened near edge arises from the odd-membered atomic ring in the defects.

• Received 23 March 1998

DOI:https://doi.org/10.1103/PhysRevB.58.10338