Effect of the substrate on the electrodeposition of Bi{sub 2}Te{sub 3-y}Se{sub y} thin films

Journal Article · Tue Jul 01 00:00:00 EDT 2008 · Materials Research Bulletin

OSTI ID:21144048

Luxia, Bu ^[1]; Hui, Wang ^[2]

---

1. Department of Applied Chemistry, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)
2. Analytical Center, Tianjin University, Tianjin 300072 (China)

The potentiostatic electrodeposition of n-type Bi{sub 2}Te{sub 3-y}Se{sub y} thermoelectric films onto stainless steel and gold substrates from nitric acid aqueous solutions has been carried out at room temperature. The cathodic process during the electrodeposition of Bi{sub 2}Te{sub 3-y}Se{sub y} films was investigated by cyclic voltammetric experiments. The structure and surface morphology of Bi{sub 2}Te{sub 3-y}Se{sub y} films deposited on both substrates were characterized by X-ray diffraction (XRD) and environment scanning electron microscopy (ESEM) coupled with energy dispersive spectroscopy (EDS). Electrical and thermoelectric properties of as-deposited films were also measured at room temperature. The results show that the reduction process under the same depositing conditions on gold and stainless steel substrates is very different. On gold substrates, H{sub 2}SeO{sub 3} in the electrolyte is firstly reduced to elemental Se, and then the deposited Se reacts with HTeO{sub 2}{sup +} and Bi{sup 3+} to form Bi{sub 2}Te{sub 3-y}Se{sub y} alloy. On stainless steel substrates, HTeO{sub 2}{sup +} in the electrolyte is firstly replaced by elemental Fe to produce elemental Te, and subsequently the generated Te reacts with H{sub 2}SeO{sub 3} and Bi{sup 3+} to form Bi{sub 2}Te{sub 3-y}Se{sub y} alloy. Analysis of ESEM show that the surface morphology of the films electrodeposited on gold substrates is more compact than that on stainless steel substrates. The XRD patterns indicate that the films electrodeposited on both substrates exhibit preferential orientation along (1 1 0) plane, but the relative peak intensity of (0 1 5) and (2 0 5) planes on stainless steel substrates is stronger than that on gold substrates. The Seebeck coefficient and electrical resistivity of the films deposited on stainless steel substrates are higher than that on gold substrates.

• OSTI ID: 21144048
• Journal Information: Materials Research Bulletin, Vol. 43, Issue 7; Other Information: DOI: 10.1016/j.materresbull.2007.07.002; PII: S0025-5408(07)00306-6; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
BISMUTH COMPOUNDS
BISMUTH IONS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRODEPOSITION
GOLD
MORPHOLOGY
NITRIC ACID
POLAROGRAPHY
SCANNING ELECTRON MICROSCOPY
SELENIDES
STAINLESS STEELS
SUBSTRATES
SURFACES
TELLURIDES
TEMPERATURE RANGE 0273-0400 K
THERMOELECTRIC PROPERTIES
THIN FILMS
X-RAY DIFFRACTION