Rapid quench annealing of Er implanted Si for quantum networking applications

Erbium-implanted silicon (Er:Si) holds promise for quantum networking, but the formation of multiple Er centers poses a challenge. We show that the cubic center (Er-C) has C_2v or lower symmetry and propose all Er centers range between full Si- and full O-coordination. By co-implanting Si with Er and O (both 10¹⁹cm^-3) and increasing the thermal anneal quenching rate from ∼100 °C/s to ∼1000 °C/s, we shifted the dominant optically active center from Er₂O₃ clusters to the Er-C center with mixed Si and O coordination. Temperature-dependent photoluminescence reveals Er₂O₃ clusters and Er-C centers have O-related defect states at ∼200 and 90 meV above the ⁴I_13/2 Er manifold, respectively.