Though no boron signal is identified, with respect to their boron content the narrow and broad components of the electron spin resonance signal in boron doped polycrystalline film decrease from 1018to 1016cm−3. This is ascribed to two different structural defects with concentration decreasing with the boron content, in agreement with theoretical predictions. Finally, we suggest a spatial location for these defects. ©1996 American Institute of Physics.