Si-NL10: Paramagnetic Acceptor State of the Silicon Thermal Donor

Electron paramagnetic resonance studies on several donor- and acceptor-doped, oxygen-rich, silicon samples have been performed. The intensity of the spectrum Si-NL10 has been investigated as a function of heat-treatment time, temperature, and illumination. The results provide evidence for an acceptor character of the Si-NL10 center strongly supporting the recently proposed idea of relating it to the silicon thermal donor level T${\mathrm{D}}^{-}$.