Regensburg 2013 – scientific programme
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O: Fachverband Oberflächenphysik
O 38: Topological Insulators (jointly with HL, MA, TT)
O 38.11: Talk
Wednesday, March 13, 2013, 12:00–12:15, H16
Local photocurrent generation in thin films of the topological insulator Bi2Se3 — •Christoph Kastl1, Tong Guan2, Xiaoyue He2, Kehui Wu2, Yongqing Li2, and Alexander Holleitner1 — 1Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4a, 85748 Garching, Germany — 2Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
We report on the optoelectronic properties of thin films of the three-dimensional topological insulator Bi2Se3 grown by molecular beam epitaxy. In spatially resolved scanning photocurrent experiments, we observe submicron photocurrent patterns with positive and negative amplitude [1]. The patterns are independent of the applied bias voltage, but they depend on the width of the circuits. We interpret the patterns to originate from a local photocurrent generation [2] due to potential fluctuations [3]. Furthermore, we verify and discuss the impact of the circular photogalvanic effect in optoelectronic Bi2Se3-based circuits [4].
C. Kastl et al., arxiv: 1210.4743 (2012).
J. C. W. Song and L. S. Levitov, arxiv:1112.5654 (2011).
H. Beidenkopf et al., Nat. Phys. 7, 939 (2011).
C. Kastl et al. (2013).