“…Though these deep-acceptors have been known since the 1960s [8,11,12,13,14,15,16,17,18], this material is novel because n-type GaAs is not usually designed to retain large concentrations of compensating acceptors. These compensating acceptors are [8,11,19,20,21,22,23] donor-vacancy-on-gallium complexes (donor-V complexes, e.g., V, Si-V, Si-V-Si, etc., where Si denotes the silicon-on-gallium-site).…”