Investigations into electron spin resonance in doped nanocrystalline silicon films

We report here the studies of electron spin resonance (ESR) and its related defect states in doped nanocrystalline silicon films (nc-Si: H). The sampl es used, which was prepared by plasma enhanced CVD method, are of two phase s in structure, i. e., nanocrystallites embedded in the amorphous matrix. F or phosphorus doped nc-Si:H samples, the measured ESR g-values are 1.9990-1 .9991, the line width DeltaH(pp)(40-42) x 10(-4) T, and the ESR density N-s s is of order of 10(17) cm(-3). For boron doped nc-Si: H samples, the measu red ESR g-values are 2.0076-2.0078, DeltaH(pp) is about 18 x 10(-4) T, and N-ss is of order of 10(16) cm(-3). Considering the micro-structural and con ducting characteristics of these kinds of-films, we discuss and give explan ations to the ESR sources, their DeltaH(pp) and N-ss as well. We ascribe th e ESR signals in phosphorus doped nc-Si:H to the unpaired electrons in the high density defect states located in the interfaces of nanocrystallites/am orphous matrix, and that in boron doped ones to the unpaired electrons in t he valence band-tail states in the a-Si:H tissue of their amorphous matrix.