Density functional theory calculations (based on GGA+U approach) were used to investigate the formation and diffusion of donor-vacancy pairs (E centers) in germanium. It was concluded that, depending upon the Fermi energy, E centers that incorporated for phosphorous and arsenic could form in their neutral, singly negatively or doubly negatively charged states whereas for antimony only the neutral or doubly negatively charged states were predicted. The activation energies of diffusion were compared with recent experimental work and support the idea that smaller donor atoms exhibited higher diffusion activation energies.

Diffusion of E Centers in Germanium Predicted using GGA+U Approach. H.Tahini, A.Chroneos, R.W.Grimes, U.Schwingenschlögl, H.Bracht: Applied Physics Letters, 2011, 99[7], 072112