Unzipping and movement of Lomer-type edge dislocations in Ge/GeSi/Si(0 0 1) heterostructures

•Reversibility of edge dislocations formation in Ge/Si heterostructures is discovered.•The direct explanation of mobility of Lomer-type dislocation is offered.•Complementary 60° dislocations are separated in the movable edge dislocations.•The strain which remains in GeSi buffer layer is the driving force for separation.