Defect formation and annihilation at GeGeO2 Ge  GeO 2 interfaces
The stability and dynamics of defects at GeGeO2 Ge  GeO 2 interfaces are key factors for the operation of Ge-based devices. Here we present the results of extensive first-principles calculations on creation mechanisms and transformations of defects at the GeGeO2 Ge  GeO 2 boundary. We find that, similar to the case of Ge P b centers, reactions between interfacial divalent Ge atoms and hydrogen or fluorine do not lead to passivation of the Ge dangling bonds. Moreover, the insertion of extra oxygen atoms in the vicinity of Pb P b and divalent Ge defects can lead to new defect complexes. The results reveal key differences with respect to the traditional Si  SiO 2 electronic system.
defects interface hydrogen fluorine oxygen ab initio germanium silicon