Electro-optical techniques and electrically detected magnetic resonance were used to investigate microcrystalline Si before and after irradiation with 1MeV electrons. Irradiation with electrons induces pronounced changes in the optical and electronic properties, namely, an increase in sub-gap absorption as measured by the constant photocurrent method and a deterioration of the dark and photoconductive properties. Electrically detected magnetic resonance measured in the photocurrent mode showed an increased dangling-bond contribution and a change in the recombination path with sample irradiation. This was also reflected in the temperature-dependent Rose factor. Below 50K, an electrically detected magnetic resonance signal was found that was attributed to the recombination of conduction electrons in shallow traps with dangling bonds. A so-called enhancement electrically detected magnetic resonance signal was also found in the dark current, with a typical g-value for dangling bonds, which was almost unaffected by electron irradiation.

Transport and Electrically Detected Electron Spin Resonance of Microcrystalline Silicon Before and after Electron Irradiation. W.Bronner, M.Mehring, R.Brüggemann: Physical Review B, 2002, 65[16], 165212 (6pp)