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Title: Thickness and growth-condition dependence of in-situ mobility and carrier density of epitaxial thin-film Bi{sub 2}Se{sub 3}

Bismuth selenide Bi{sub 2}Se{sub 3} was grown by molecular beam epitaxy, while carrier density and mobility were measured directly in situ as a function of film thickness. Carrier density shows high interface n-doping (1.5 × 10{sup 13 }cm{sup −2}) at the onset of film conduction and bulk dopant density of ∼5 × 10{sup 11 }cm{sup −2} per quintuple-layer unit, roughly independent of growth temperature profile. Mobility depends more strongly on the growth temperature and is related to the crystalline quality of the samples quantified by ex-situ atomic force microscopy measurements. These results indicate that Bi{sub 2}Se{sub 3} as prepared by widely employed parameters is n-doped before exposure to atmosphere, the doping is largely interfacial in origin, and dopants are not the limiting disorder in present Bi{sub 2}Se{sub 3} films.
Authors:
;  [1] ;  [2] ; ;  [1] ; ;  [3]
  1. School of Physics, Monash University, Victoria 3800 (Australia)
  2. (United States)
  3. Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111 (United States)
Publication Date:
OSTI Identifier:
22310681
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ATOMIC FORCE MICROSCOPY; BISMUTH SELENIDES; CARRIER DENSITY; CARRIER MOBILITY; CRYSTAL GROWTH; DOPED MATERIALS; INTERFACES; MOLECULAR BEAM EPITAXY; THICKNESS; THIN FILMS