The influence of erbium on the physical properties of GaN crystals grown from N solution in Ga at high nitrogen pressure

Oxygen contamination is the main source of free electrons in bulk GaN grown at high-pressure. We used erbium as a promising getter/compensation center to reduce the electron content in GaN. Both optical and electrical measurements indicate the reduction of electron concentration from the initial 6 × 10 19 cm −3 down to 1 × 10 19 cm −3 . A photoluminescence study proves that erbium is incorporated into the GaN host lattice, and emits light at ∼ 1.5μm.