By using ab initio total-energy calculations, an investigation was made of the effects of stacking faults on the properties of dopants in pure and n-type doped samples. It was found that impurity Si segregated towards the stacking faults. A Si atom at a Ga site in a stacking fault, in either a neutral or a negative charge state, was energetically favourable (as compared to a Si atom at a Ga site in a crystalline environment) by up to 0.2eV. It was also found that a Si impurity in a stacking fault could not occupy a metastable position, as in the formation of DX centres. Stacking faults could therefore prevent the formation of DX-like centres.

Stacking Fault Effects in Pure and n-Type Doped GaAs. T.M.Schmidt, J.F.Justo, A.Fazzio: Applied Physics Letters, 2001, 78[7], 907-9