Electron energy-loss spectra and atomic column images were obtained from a dissociated 60º misfit dislocation at the substrate interface of a strained Si quantum well. The Si 2p3/2 electron energy-loss spectra from the stacking fault revealed a splitting of the L1 conduction band minimum; caused by third-nearest neighbour interactions at the fault. Spectra from the 30º dislocation exhibited a similar splitting as well as in-gap defect electronic states. Spectra from the 90º dislocation also revealed evidence of in-gap states, but did not exhibit the L1 splitting. An extended core structure, based upon a double-period pairing reconstruction was expected to be able to explain this lack of L1 splitting.

Atomic and Electronic Structure of a Dissociated 60º Misfit Dislocation in GexSi1-x P.E.Batson: Physical Review Letters, 1999, 83[21], 4409-12