Scanning tunneling microscopy of Bi2Te3 films prepared by pulsed laser deposition: from nanocrystalline structures to van der Waals epitaxy

Surfaces and Interfaces. 2022. Vol. 31. Article 102015.

N.I. Fedotov, Maizlakh A. A., V.V. Pavlovskiy, Rybalchenko G. V., S.V. Zaitsev-Zotov

Bi2Te3 is a material with high efficiency of thermoelectric energy conversion. Recently, it was also recognized as a topological insulator, and is often used as the basis for creation of other types of topological matter. Pulsed laser deposition (PLD) is widely considered as a simple method for growing of multicomponent films, but not as a tool for van der Waals epitaxy. We demonstrate here that the van der Waals epitaxy of Bi2Te3 is indeed impossible in vacuum PLD, but is possible in the presence of a background gas, which is confirmed by the results of scanning tunneling microscopy and spectroscopy studies. Results of ab initio calculations reproduce tunneling spectra of the first three terraces of epitaxial films of Bi2Te3. In addition, an unusual hexagonal superstructure resembling a charge-density wave is observed in overheated films.

Keywords: thin films, сканирующая туннельная микроскопия, scanning tunneling microscopy, Поверхность и тонкие пленки, pulsed laser deposition, импульсное лазерное напыление, Scanning tunneling spectroscopy, сканирующая туннельная спектроскопия, Bi₂Te₃, Van der Waals epitaxy, Bi2Te3, эпитаксия ван дер Ваальса