It was found that, although no B signal was identified, the narrow and broad components of the electron spin resonance signals from B-doped polycrystalline films decreased in going from 1018 to 1016/cm3. This was attributed to 2 different structural defects whose concentrations decreased with the B content, in agreement with theoretical predictions. It was concluded that the most important point was the decrease in spin concentration which occurred as the B content increased. No suitable model could be found to explain the variations which were observed here. However, B3/2 and B1/2 appeared as reduced variables in the case of the narrow and broad components, respectively. It was suggested that the corresponding defects might be situated in zones with a higher defect concentration, such as near to the grain boundaries (which would lead to a term in B/cm2) or near to the internal surfaces of elongated micro-voids (which would lead to a term that was between B/cm and B/cm2). Higher concentrations of structural defects near to the grain boundaries, and the occurrence of micro-voids, had already been reported to exist within the grains of polycrystalline films.

E.Colineau, A.Deneuville, J.Mambou, E.Gheeraert: Applied Physics Letters, 1996, 68[15], 2123-5