Electrochemical Scanning Tunneling Microscopy Study of Bismuth Chalcogenide Single Crystals.

Author(s) Yang, C.; Huang, Y.; Golden, M.S.; Schwarzacher, W.
Journal Langmuir
Date Published 2019 Nov 12
Abstract

We use electrochemical scanning tunneling microscopy (EC-STM) to image single-crystal surfaces of the layered bismuth chalcogenide SnBiTeSe in situ under electrochemical control for the first time. The Bi chalcogenides are of interest for their thermoelectric properties and as model topological insulators (TIs). We show that oxidative dissolution takes place via the progressive nucleation of pits in the initially smooth surface terraces rather than at their edges. Nanometer-resolution EC-STM images show that the pit depth is generally equal to the thickness of a complete chalcogenide quintuple layer. The preferential redeposition of dissolved components at step and defect edges on application of a more negative potential after oxidation is observed. Our work demonstrates the ability to control and characterize the surface morphology of single-crystal TIs in an electrochemical environment.

DOI 10.1021/acs.langmuir.9b03062
ISSN 1520-5827
Citation Yang C, Huang Y, Golden MS, Schwarzacher W. Electrochemical Scanning Tunneling Microscopy Study of Bismuth Chalcogenide Single Crystals. Langmuir. 2019.