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arXiv · 1502.07844

Chemical Potential Fluctuations in Topological Insulator (Bi$_{0.5}$Sb$_{0.5}$)$_2$Te$_3$ Films Visualized by Photocurrent Spectroscopy

Christoph Kastl·Paul Seifert·Xiaoyue He·Kehui Wu·Yongqing Li·Alexander Holleitner
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Abstract

We investigate the photocurrent properties of the topological insulator (Bi$_{0.5}$Sb$_{0.5}$)$_2$Te$_3$ on SrTiO$_3$-substrates. We find reproducible, submicron photocurrent patterns generated by long-range chemical potential fluctuations, occurring predominantly at the topological insulator/substrate interface. We fabricate nano-plowed constrictions which comprise single potential fluctuations. Hereby, we can quantify the magnitude of the disorder potential to be in the meV range. The results further suggest a dominating photo-thermoelectric current generated in the surface states in such nanoscale constrictions.

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Christoph Kastl, Paul Seifert, Xiaoyue He, Kehui Wu, Yongqing Li, Alexander Holleitner. 2015-02-27. Chemical Potential Fluctuations in Topological Insulator (Bi$_{0.5}$Sb$_{0.5}$)$_2$Te$_3$ Films Visualized by Photocurrent Spectroscopy. https://doi.org/10.1088/2053-1583%2F2%2F2%2F024012

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