The dependence, upon their charge state, of structural relaxations around P vacancies on (110)InP and (110)GaP surfaces was investigated by means of scanning tunnelling microscopy. Two charge transition levels were localized within the band gap. The symmetry of the vacancies decreased with an increasing number of electrons bonded into electronic defect states. The vacancies on the (110)InP and (110)GaP surfaces had essentially the same structure.

P.Ebert, K.Urban, M.G.Lagally: Physical Review Letters, 1994, 72[6], 840-3