The defect center, with a zero-phonon line energy at about 0.922eV, was produced by annealing at temperatures of 450 to 550C for times ranging from 8h to weeks. Uniaxial stress measurements showed that the defect symmetry was monoclinic (point-group C1h). The results indicated that the defect was an Al-C complex. An analogy was found between this defect and a previously reported Al pair defect which exhibited almost identical uniaxial stress and Zeeman behaviors and a zero-phonon line-energy difference of about 0.037eV.

Photoluminescence spectroscopy of an Al-C complex in silicon E.McGlynn, M.O.Henry, P.McLoughlin, E.C.Lightowlers: Physical Review B, 1999, 59[15], 10084-90