Aggregate defects of gold and platinum with lithium in silicon: II. Electronic-structure calculations

Spectroscopic study and structural characterization of a Li-related photoluminescence center in neutron-irradiated Si

“…Two structured components can be seen at 879.07 meV ͑a weak component͒ and at 879.25 meV ͑a strong component͒. The measured integrated intensity for these components, 0.07:0.93, is very similar to the natural isotope abundance of 6 Li: 7 Li, suggesting that the ZPL is perturbed by the effects of one Li atom. This result is confirmed by the isotopic structure displayed by the present ZPL in crystals doped with different 6 Li: 7 Li isotopic ratios ͓Fig.…”

“…We employed four parallelepiped single crystals of 2ϫ2ϫ18 mm 3 oriented along ͗100͘, ͗111͘, and two along ͗110͘ for exploring the PL polarization with stress along ͗110͘ and viewing along either the ͗11 0͘ or the ͗001͘ directions. The isotope structure was investigated with different 6 Li: 7 Li ratios using the same Li-doped Si crystal series employed elsewhere. 9 The crystals were neutron irradiated at room temperature with a dose of 1ϫ10 17 cm Ϫ2 1-MeV equivalent and then annealed during 30-60 min at 550-650°C.…”

“…Due to their high mobility, lithium and hydrogen are important impurities in silicon that can passivate many defects giving rise to different Li and H associated complexes. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] In general, H-related defects have received considerable attention due to the role played by hydrogen in modifying the electrical and optical properties of semiconductors, 16 and are a current theme of interest. The ability of H to form complexes with different defects and impurities has been clearly evidenced in Si by the great number of known defects which in recent years have been shown to contain H. [14][15][16] This behavior suggests that similar phenomena could probably occur when the next high-mobile hydrogenic impurity, Li, is present in Si.…”

“…Although many Li centers have been reported for many years in the literature, [2][3][4][5][6][7][8][9][10][11][12] the structural characterization for most of them still remains unknown. The reasons for this lack of structural information lie in the difficulties of obtaining suitable crystals doped with different isotopes and in understanding the chemical processes involved in the formation of the centers.…”

Excitation spectrum of a PtLi-related center in silicon

“…1,2 Two different centers were observed by EPR, one with orthorhombic I (C 2v ) and one with trigonal symmetry (C 3v ). The electronic structure of isolated substitutional Pt center is well know from previous work [3][4][5][6] and the applicability of the Watkin's vacancy model 7 for this center has been confirmed.…”