Compensation mechanisms which related semi-insulating material to intrinsic n-type material were investigated by means of first-principles total energy calculations. Two intrinsic defects were shown to play an important role in such annealing-induced transitions from n-type to semi-insulating. The single defect, VIn3-, resulted from In-vacancy-H-complexes which, before annealing, were identified (in infra-red spectra) as being responsible for n-type conductivity. The PIn+VP complex arose from diffusion of the neutral In vacancy. Both defects were shown to produce localized levels, within the band-gap, which compensated the free electron.

Ab initio Calculations of the Compensation Mechanisms in InP. T.M.Schmidt, R.H.Miwa, A.Fazzio, R.Mota: Solid State Communications, 2001, 117[6], 353-5