Optimizations of Pulsed Plated p and n-type Bi2Te3-Based Ternary Compounds by Annealing in Different Ambient Atmospheres

Autor: Geert Rampelberg, Christian Schumacher, Lewis Akinsinde, Julien Bachmann, Svenja Baessler, Klaus G. Reinsberg, José A. C. Broekaert, Kornelius Nielsch, Raimar Rostek, Sebastian Zastrow, Peter Woias, Christophe Detavernier
Rok vydání: 2012
Předmět:
Zdroj: Advanced Energy Materials. 3:95-104
ISSN: 1614-6832
DOI: 10.1002/aenm.201200417
Popis: This work presents a comprehensive study of the fabrication and optimization of electrodeposited p- and n-type thermoelectric fi lms. The fi lms are deposited on Au and stainless steel substrates over a wide range of deposition potentials. The infl uence of the preparative parameters such as the composition of the electrolyte bath and the deposition potential are investigated. Furthermore, the p-doped (Bi x Sb 1−x ) 2 Te 3 and the n-doped Bi 2 (Te x Se 1−x ) 3 fi lms are annealed for a period of about 1 h under helium and under tellurium atmosphere at 250 ° C for 60h. Annealing in He already leads to signifi cant improvements in the thermoelectric performance. Furthermore, due to the equilibrium conditions during the process, annealing in Te atmosphere leads to a strongly improved fi lm composition, charge carrier density and mobility. The Seebeck coeffi cients increase to values up to + 182 μ V K − 1 for p-doped and‐130 μ V K − 1 for n-doped materials at room temperature. The power factors also exhibit improvements with 1320 μ W m − 1 K − 2 and 820 μ W m − 1 K − 2 for p-doped and n-doped fi lms, respectively. Additionally, in-situ XRD measurements performed during annealing of the fi lms up to 600K under He atmosphere show stepwise improvements of the crystal structure leading to the improvements in thermoelectric parameters. The thermal conductivity is between 1.2 W m − 1 K − 1 and 1.0 W m − 1 K − 1 .
Databáze: OpenAIRE