Effects of post-annealing on thermoelectric properties of bismuth–tellurium thin films deposited by co-sputtering
| Autor: | Haseok Jeon, Hoo-Jeong Lee, Seungmin Hyun, Minsub Oh, Seong-jae Jeon |
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| Rok vydání: | 2011 |
| Předmět: |
Materials science
Annealing (metallurgy) Mineralogy chemistry.chemical_element Sputter deposition Condensed Matter Physics Microstructure Atomic and Molecular Physics and Optics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Bismuth chemistry Sputtering Seebeck coefficient Thermoelectric effect Electrical and Electronic Engineering Thin film Composite material |
| Zdroj: | Microelectronic Engineering. 88:541-544 |
| ISSN: | 0167-9317 |
| DOI: | 10.1016/j.mee.2010.06.036 |
| Popis: | This paper reports the microstructure evolution of Bi-Te thermoelectric films upon post-annealing and its effects on the thermoelectric properties. Bi-Te films with the composition of around 61at.% Te and the thickness of 300nm were deposited onto SiO"2-coated Si substrates by using bismuth and tellurium targets in a radio frequency (RF) magnetron sputtering system. We annealed the films at different temperatures (100, 150 and 200^oC) under N"2 ambient for 8h, and characterized the crystallinity and morphology of the Bi-Te films. Microstructure characterization using X-ray diffraction and scanning electron microscopy disclosed that the post-annealing treatment entailed a drastic microstructural evolution by inducing the development of a strong texture of grains with their c-axis oriented normal to the substrate. In addition, we measured the electrical transport and thermoelectric properties of the films to reveal their close link with the microstructure changes. The electron mobility and Seebeck coefficient increase significantly, leading to a remarkable improvement in the power factor from [email protected]/K^2cm for the as-deposited sample to [email protected]/K^2cm for the 200^oC-annealed sample. |
| Databáze: | OpenAIRE |
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