Dynamic in situ observations of electrical and structural changes in thin thermoelectric (Bi{sub 0.15}Sb{sub 0.85}){sub 2}Te{sub 3} films

Journal Article · Tue Sep 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3225610· OSTI ID:21361838

Bertram, Katrin ^[1]; Stordeur, Matthias ^[2]; Heyroth, Frank; Leipner, Hartmut S ^[1]

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1. Interdisziplinaeres Zentrum fuer Materialwissenschaften, Martin-Luther-Universitaet Halle-Wittenberg, Heinrich-Damerow-Str. 4, D-06120 Halle (Germany)
2. HTC HighTech Consulting, Hallesche Str. 50, D-06122 Halle (Germany)

Thin films of (Bi{sub 0.15}Sb{sub 0.85}){sub 2}Te{sub 3} were prepared by dc magnetron sputter deposition on different substrates. It is well known that thermal treatment of as-deposited p-type (Bi{sub 0.15}Sb{sub 0.85}){sub 2}Te{sub 3} films leads to an enhancement of the power factor. Whereas up to now only the initial (as deposited) and the final (after annealing) film stages have been investigated, here, the dynamic changes of sputter-deposited film properties have been observed by in situ measurements. The enhancement of the power factor shows a significant dependence on thermal treatment. The best thermoelectric films have been prepared at a substrate temperature of 170 deg. C, with a power factor of 24.4 muW/(cm K{sup 2}). The changes in the Seebeck and Hall coefficients are caused by the enhancement in the Hall mobility after annealing. In situ x-ray diffractometry shows the generation of additional Te in dependence of the temperature. This is also confirmed by energy-dispersive x-ray microanalysis and the corresponding mapping in a scanning electron microscope. It is supposed that the locally well-defined Te enrichment is the reason for the improvement in the integral film transport properties.

• OSTI ID: 21361838
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 6; Other Information: DOI: 10.1063/1.3225610; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
ANTIMONY COMPOUNDS
BISMUTH COMPOUNDS
CHEMICAL ANALYSIS
DEPOSITION
MICROANALYSIS
POWER FACTOR
SCANNING ELECTRON MICROSCOPY
SEEBECK EFFECT
SEMICONDUCTOR MATERIALS
SPUTTERING
THIN FILMS
X-RAY DIFFRACTION
COHERENT SCATTERING
DIFFRACTION
DIMENSIONLESS NUMBERS
ELECTRON MICROSCOPY
FILMS
HEAT TREATMENTS
MATERIALS
MICROSCOPY
SCATTERING