Ordered Growth of Topological Insulator Bi2Se3 Thin Films on Dielectric Amorphous SiO2 by MBE

TL;DR

This paper demonstrates the successful ordered growth of topological insulator Bi2Se3 thin films on amorphous SiO2 substrates using molecular beam epitaxy, enabling potential applications in TI-based devices.

Contribution

It introduces a Se passivation method to suppress phase formation, achieving van der Waals epitaxy of Bi2Se3 on amorphous surfaces, which was previously challenging.

Findings

Bi2Se3 films grow along [001] with good periodicity

Weak anti-localization effect observed with gating response

Ordered growth advantageous for TI-junction applications

Abstract

Topological insulators (TIs) are exotic materials which have topologically protected states on the surface due to the strong spin-orbit coupling. However, a lack of ordered growth of TI thin films on amorphous dielectrics and/or insulators presents a challenge for applications of TI-junctions. We report the growth of topological insulator Bi2Se3 thin films on amorphous SiO2 by molecular beam epitaxy (MBE). To achieve the ordered growth of Bi2Se3 on amorphous surface, the formation of other phases at the interface is suppressed by Se passivation. Structural characterizations reveal that Bi2Se3 films are grown along the [001] direction with a good periodicity by van der Waals epitaxy mechanism. Weak anti-localization effect of Bi2Se3 films grown on amorphous SiO2 shows modulated electrical property by the gating response. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surface presents considerable advantages for TI-junctions with amorphous insulator or dielectric thin films.