Optimization of In₂Se₃/Si(111) Heteroepitaxy To Enable Bi₂Se₃/In₂Se₃ Bilayer Growth

Abstract

Systematic optimization of molecular beam epitaxy growth parameters enabled high quality heteroepitaxy of In 2 Se 3 on Si(111) surfaces. Surfaces of the best epilayers were characterized by atomically flat terraces that extended laterally for several hundred nanometers. These terraces were separated by single quintuple layer high steps. These In 2 Se 3 films were suitable for subsequent high quality epitaxy of Bi 2 Se 3 . The quality of the In 2 Se 3 /Bi 2 Se 3 interface was confirmed using atomic resolution transmission electron microscopy.

Topological Insulator Film Growth by Molecular Beam Epitaxy: A Review

“…Thus, theoretically, using In 2 Se 3 as a buffer layer could enhance the crystal quality of Bi 2 Se 3 films. Systematic optimization of MBE growth parameters of In 2 Se 3 on Si(111) substrate was reported by Rathi et al [43]. The authors concluded that the In 2 Se 3 layers that are most suitable for Bi 2 Se 3 growth resulted from a three-step growth sequence: Se passivation of the Si substrate at 100 • C, In 2 Se 3 codeposition with a temperature ramp from 100 • C to 400 • C, followed by Se anneal at 400 • C. They also successfully grew Bi 2 Se 3 on top of In 2 Se 3 with a sharp interface.…”