Thickness and growth-condition dependence of in-situ mobility and carrier density of epitaxial thin-film Bi{sub 2}Se{sub 3}
- School of Physics, Monash University, Victoria 3800 (Australia)
- Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742-4111 (United States)
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.
- OSTI ID:
- 22310681
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
Similar Records
Topological insulator Bi{sub 2}Se{sub 3} thin films grown on double-layer graphene by molecular beam epitaxy
P-type conductivity in Sn-doped Sb 2 Se 3