Indium interaction with the Bi$_2$Se$_3$(0001) surface under the low-temperature deposition

The adsorption of indium atoms on the Bi$_2$Se$_3$(0001) surface at room temperature followed by annealing at 200$^\circ$C was studied using in situ reflection electron microscopy, angle-resolved photoelectron spectroscopy and X-ray photoelectron spectroscopy. The formation of a heterostructure in the form of a Bi(111) bilayer on the Bi$_2$Se$_3$(0001) surface and the formation of an In–Se chemical bond, which corresponded to the emergence of bismuth atoms on the surface from the near-surface layer with the next formation of a Bi(111) islands were shown. Regions with an increased indium content surrounded by labyrinthine bismuth islands without pronounced step faceting were observed by scanning electron microscopy in the backscattered electron mode. Bismuth islands Bi(111) with a height of $\approx$ 0.4 nm were also observed by atomic force microscopy.