Rapid quench annealing of Er implanted Si for quantum networking applications

Erbium-implanted silicon (Er) holds promise for quantum networking, but the formation of multiple Er centres poses a challenge. We show that the cubic centre (Er-C) has C2v or lower symmetry, with Er centres ranging from fully Si- to fully O-coordinated. By co-implanting Si with Er and O (each at 1019 cm-3) and increasing the thermal anneal quenching rate from ~100 °C/s to ~1000 °C/s, we shifted the dominant optically active centre from Er2O3 clusters to the less stable Er-C centre with mixed Si and O coordination. Temperature-dependent photoluminescence reveals Er2O3 clusters and Er-C centres have O-related defect states at ~200 and 90 meV above the 4I13/2 Er manifold, respectively.