The interaction of H with substitutional chalcogen impurities (S, Se, or Te) was investigated by ab initio modeling. In Se-Hn and Te-Hn complexes (n = 1, 2), protons were located at sites antibonding to nearest-neighbor Si atoms. For S, two competitive sites for S-H were found, resulting in 2 nearly degenerate structures. All the singly hydrogenated complexes were predicted to be shallow donors with levels lying above those of the substitutional S, Se, and Te double donors. In contrast, doubly hydrogenated chalcogen impurities were predicted to be electrically inert. A comparison of the results with experimental data suggested that the NL60 and NL61 electron-paramagnetic-resonance centers could be identified with two Se-H defects, where H was antibonded to a Si neighbor of Se.

Electrical Activity of Chalcogen-Hydrogen Defects in Silicon. J.Coutinho, V.J.B.Torres, R.Jones, P.R.Briddon: Physical Review B, 2003, 67[3], 035205 (11pp)