Speaker
Description
Abstract
We present the results of the characterization of the topological insulator (TI) Bi2Te3 in four different environments using scanning probe microscopy (SPM) based techniques. Upon exposure to air at room temperature the cleaved surface of the pristine Bi2Te3 is observed to be strongly modified during scanning tunneling microscopy (STM) measurements. Remarkably, there is no surface alteration observed when probing Bi2Te3 samples in ultrahigh-vacuum by STM, both at low temperature (4.5 K) and at room temperature. STM experiments in an organic solvent environment show that the Bi2Te3 surface at the liquid/solid interface is modified as well, yet an enhanced stability was observed when using solutions containing perylene tetracarboxylic diimide (PDI). Finally, in a nitrogen gas environment (0% relative humidity) the Bi2Te3 surface demonstrated an increased surface stability and only very limited changes during STM scanning when compared to ambient conditions (30% relative humidity). We believe that the reduced surface stability upon exposure to ambient conditions is triggered by a combination of effects that are discussed in our poster. Only a limited number of studies investigate the behavior of the surface of the TI Bi2Te3 under ambient conditions when using SPM techniques 1-3. Controlled surface modification can pave the way towards new possibilities for surface patterning at nanometer scale. Our findings are crucial for further in depth studies of the intrinsic properties of the 3D TI Bi2Te3 and for potential applications that include room temperature TI devices operated under ambient conditions.
References
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