First-principles study of atomic structures and electronic properties of ultrathin Bi films on Ge(111)

摘要: Abstract The atomic and electronic structures of ultrathin bismuth films on Ge(111) surface were investigated using first-principles calculations at Bi coverages ranging from 1/3 ML to 5 ML. Morphology the surfaces varied as coverage was increased. first layer atoms followed well-known trimer model, exhibiting large Rashba spin-splittings. At 2 ML, second monolayer form stacking trimers, whereas 3 ML 5 ML, two topmost monolayers a buckled honeycomb structure. While layers exhibit two-dimensional nontrivial topological insulating phase, lying under these play an important role in p -type doping system.