The introduction of optically active defects (such as atomic clusters, dislocations, precipitates) into a Si single crystal using irradiation, plastic deformation, or heat treatment was considered a possible approach to the design of Si-based light-emitting structures in the near infra-red region. Defects were introduced into Si plates by traditional mechanical polishing. The changes in the defect structure and the impurity composition of damaged Si layers during thermal annealing (TA) of a crystal were examined using transmission electronic microscopy and X-ray fluorescence. Optical properties of the defects were studied at 77K using photoluminescence in the near infra-red region. It was shown that the defects generated by mechanical polishing transform into dislocations and dislocation loops and that SiO2 precipitates also form as a result of annealing at 850 to 1000C. Depending on the annealing temperature, either oxide precipitates or dislocations decorated by Cu atoms, which were gettered from the crystal bulk, make the predominant contribution to photoluminescence spectra.

Structure, Impurity Composition and Photoluminescence of Mechanically Polished Layers of Single-Crystal Silicon. R.I.Batalov, R.M.Bayazitov, N.M.Khusnullin, E.I.Terukov, V.K.Kudoyarova, G.N.Mosina, B.A.Andreev, D.I.Kryzhkov: Physics of the Solid State, 2005, 47[1], 1-4