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Title: Surface and interface states of Bi{sub 2}Se{sub 3} thin films investigated by optical second-harmonic generation and terahertz emission

We investigate the surface and interface states of Bi{sub 2}Se{sub 3} thin films by using the second-harmonic generation technique. Distinct from the surface of bulk crystals, the film surface and interface show the isotropic azimuth dependence of second-harmonic intensity, which is attributed to the formation of randomly oriented domains on the in-plane. Based on the nonlinear susceptibility deduced from the model fitting, we determine that the surface band bending induced in a space charge region occurs more strongly at the film interface facing the Al{sub 2}O{sub 3} substrate or capping layer compared with the interface facing the air. We demonstrate that distinct behavior of the terahertz electric field emitted from the samples can provide further information about the surface electronic state of Bi{sub 2}Se{sub 3}.
Authors:
; ;  [1] ; ; ;  [2] ; ;  [3] ; ;  [4] ; ;  [5] ;  [6] ;  [7] ; ; ;  [8]
  1. Department of Physics and Photon Science, School of Physics and Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)
  2. Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)
  3. Department of Physics, Korea University, Seoul 136-701 (Korea, Republic of)
  4. Department of Physics, University or Seoul, Seoul 130-743 (Korea, Republic of)
  5. Department of Applied Physics, College of Applied Science, Kyung Hee University, Yongin 446-701 (Korea, Republic of)
  6. Department of Electrical and Computer Engineering, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States)
  7. Department of Physics and Astronomy, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States)
  8. Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22489397
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AIR; ALUMINIUM OXIDES; BISMUTH SELENIDES; COORDINATES; CRYSTALS; ELECTRIC FIELDS; EMISSION; HARMONIC GENERATION; INTERFACES; LAYERS; NONLINEAR PROBLEMS; SPACE CHARGE; SPACE DEPENDENCE; SUBSTRATES; SURFACES; THIN FILMS