Using electron paramagnetic resonance, it was found that vacuum annealing at 200C leads to a significant reduction in the silicon dangling bond (Si-db) defect density in silicon nanoparticles (Si-NPs). The best improvement of the Si-db density by a factor of 10 was obtained when the vacuum annealing was combined with an etching step in hydrofluoric acid, whereas HF etching alone only removes the Si-dbs at the Si/SiO2 interface. The reduction in the Si-db defect density was confirmed by photothermal deflection spectroscopy and photoconductivity measurements on thin Si-NPs films.

Defect Reduction in Silicon Nanoparticles by Low-Temperature Vacuum Annealing. S.Niesar, A.R.Stegner, R.N.Pereira, M.Hoeb, H.Wiggers, M.S.Brandt, M.Stutzmann: Applied Physics Letters, 2010, 96[19], 193112