Electron spin resonance in doped nanocrystalline silicon films

Abstract We report studies of electron spin resonance (ESR) and its related defect states in doped nanocrystalline silicon films (nc-Si:H). The samples used, which were prepared by the plasma enhanced CVD method, contain two phases, i.e. nanocrystallites embedded in an amorphous matrix. For phosphorus doped nc-Si:H samples, the measured ESR g -values are 1.9990–1.9991, the line width Δ H pp 40–42 G, and the ESR density N ss is of order of 10 17  cm −3 . For boron doped nc-Si:H samples, the measured ESR g -values are 2.0076–2.0078, the Δ H pp is about 18 G, and the N ss is of order of 10 16  cm −3 . Considering the micro-structural and conducting characteristics of these kinds of films, we discuss and give explanations to the ESR sources, their Δ H pp and N ss as well. We intend to ascribe the ESR signal in phosphorus doped nc-Si:H to the unpaired electrons in the high density defect states located in the interfaces of nanocrystallites/amorphous matrix, and that in boron doped ones to the unpaired electrons in the valence band-tail states in the a-Si:H tissue of their amorphous matrix.