A thorough investigation by means of perturbation spectroscopy and electron paramagnetic resonance has been carried out on the line spectrum at about 8000 ${\mathrm{cm}}^{\mathrm{-}1}$, recently observed in platinum-doped silicon. The uniaxial stress and Zeeman results show that this center has tetrahedral symmetry. The optical transitions are conclusively identified as excitations to donorlike excited states from a ${\Gamma }_7$($T_2$) ground state, and substitutional Pt in its singly positively charged state is suggested as the center’s chemical origin.

• Received 17 May 1989

DOI:https://doi.org/10.1103/PhysRevB.40.6196