Epitaxial growth of Bi2Se3 in the (0015) orientation on GaAs (001)

Abstract

Materials with van der Waals bonding show exotic physics and may have applications in a variety of areas including new optoelectronic devices, spintronic devices, and as quantum materials. To date, control over the morphology and surface orientation of thin films of these materials without substrate pretreatment has been difficult. In this paper, the authors report the growth of Bi2Se3 on GaAs (001) substrates. By controlling the growth conditions and adatom mobility, the authors are able to obtain epitaxial growth in the (0015) orientation without substrate prepatterning. Although the growth window is small, this demonstration opens the door for future control of the orientation of van der Waals materials through control of parameters during growth and via interaction with the substrate.

Self-assembled nanocolumns in Bi2Se3 grown by molecular beam epitaxy

“…Additionally, reduced dangling bonds on the side walls would reduce bismuth adatom incorporation, explaining the GaN nanowire like growth dynamic. [34][35][36][37] When we use lower selenium overpressures but otherwise similar growth conditions, we do not observe the nanocolumn morphology 38 .…”

Optimization of the Growth of the Van der Waals Materials Bi2Se3 and (Bi0.5In0.5)2Se3 by Molecular Beam Epitaxy

“…The Bi 2 Se 3 film grown on GaAs is characterized similarly, as shown in the violet (parallel to GaAs [01̅1]) and gray (perpendicular to GaAs [01̅1]) curves. As pointed out in refs and , an extra peak at 29.5° appears if the unwanted Bi 2 Se 3 (101̅5) orientation is present as a non-negligible fraction of the film. Because of the (101̅5) preferential alignment with the GaAs [011] axis, the XRD diffraction peak is more prominent when the X-ray beam is parallel to the GaAs [01̅1] axis.…”

“…The grow–anneal strategy shows a significant effect on the morphology of Bi 2 Se 3 on GaAs . It was shown that more annealing time favors the (101̅5) orientation of Bi 2 Se 3 flakes, while the size of the flakes shrinks.…”

“…Again, the bismuth adatoms have long diffusion lengths along the GaAs [011] axis, which promote the formation of the (101̅5) orientation with more annealing time rather than the desired (0001) orientation. For details, please see ref .…”

Crystalline materials for quantum computing: Semiconductor heterostructures and topological insulators exemplars

“…Growth of (101 5) Bi 2 Se 3 has been achieved by patterning the substrate 73 or through growth at high substrate temperature and high selenium overpressure on GaAs (001) substrates. 74 Bi 2 Se 3 nanoparticle growth has been demonstrated via exposing bismuth droplets to a selenium flux. 75 More exotic 3D features such as columns and nanoplates have also been reported.…”