Cu complex in silicon and its photoluminescence

A recent discovery of complicated isotope shifts of PL 1014‐meV line in Cu‐containing silicon, which was made by Thewalt’s group, indicates that existing models of Cu pair are not appropriate for the luminescence center. Our previous study shows that the most probable form of the complex is a four‐membered complex Cu(s)Cu(3i); the symmetry is C3v. For interpreting the complicated splitting for Γ4 excition peak, involvement of a non‐totally symmetric mode is proposed. The normal modes of this complex has been obtained by ab initio phonon calculation with explicit symmetry.