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

Journal Article · Mon Feb 01 00:00:00 EST 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4941420· OSTI ID:22489397

Hamh, S. Y.; Park, S. -H.; Jerng, S. -K.; Jeon, J. H.; Chun, S. H. ^[1]; Jeon, J. H.; Kahng, S. J. ^[2]; Yu, K.; Choi, E. J. ^[3]; Kim, S.; Choi, S. -H. ^[4]; Bansal, N. ^[5]; Oh, S. ^[6]; Park, Joonbum; Kho, Byung-Woo; Kim, Jun Sung ^[7]

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1. Department of Physics and Graphene Research Institute, Sejong University, Seoul 143-747 (Korea, Republic of)
2. Department of Physics, Korea University, Seoul 136-701 (Korea, Republic of)
3. Department of Physics, University or Seoul, Seoul 130-743 (Korea, Republic of)
4. Department of Applied Physics, College of Applied Science, Kyung Hee University, Yongin 446-701 (Korea, Republic of)
5. Department of Electrical and Computer Engineering, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States)
6. Department of Physics and Astronomy, Rutgers, The state University of New Jersey, Piscataway, New Jersey 08854 (United States)
7. Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

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}.

• OSTI ID: 22489397
• Journal Information: Applied Physics Letters, Vol. 108, Issue 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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