Constructing topological insulator-ferromagnet heterojunctions of Bi2Se3/ Fe3GeTe2 and Bi2Te3/ Fe3GaTe2

Abstract Heterostructures composed of topological insulators and ferromagnets are predicted to exhibit the quantum anomalous Hall effect (QAHE). The morphology and interfacial structure have a significant impact on the physical properties and transport performance of such heterostructures. Here, we report the epitaxial growth of topological insulators Bi2Se3 and Bi2Te3 thin films on ferromagnetic substrates of Fe3GeTe2 and Fe3GaTe2, respectively. The morphology and composition of the Bi2Se3 and Bi2Te3 thin films were characterized using atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. After optimizing the growth parameters, we successfully generated large-area films with high crystallinity, presenting new types of topological insulator-ferromagnet heterojunctions for the pursuit of the QAHE.