Study of the Annealing Effects of Sputtered Bi2Te3 Thin Films with Full Thermoelectric Figure of Merit Characterization

Naumochkin M, Park GH, Nielsch K, Reith H (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Physica Status Solidi-Rapid Research Letters Wiley-VCH Verlag

Book Volume: 16

Article Number: 2100533

Journal Issue: 4

DOI: 10.1002/pssr.202100533

Abstract

Micro-thermoelectric (TE) devices have a great potential for future applications in the field of energy harvesting to power autonomous sensors. Bi2Te3 sputtered at elevated substrate temperatures exhibits a high figure of merit (ZT) suitable for the fabrication of micro-TE devices. However, a lift-off process that does not allow higher substrate temperatures is often used, and although Bi2Te3 is a well-studied TE material, it lacks full ZT characterization of thin films. Herein, the full TE characterization of sputtered Bi2Te3 thin films is presented, including the charge carrier concentration and mobility, which are deposited at room temperature and postannealed between 150 and 300 °C. The influence of the annealing time and temperature is investigated on a 90 nm-thick Bi2Te3 film. A maximum ZT of 0.20 is found, which results from the increasing crystallinity and reduction of point defects. To investigate the thickness dependency, Bi2Te3 films with thicknesses of 90, 170, 350, and 470 nm are annealed at 250 °C. A maximum ZT value of 0.26 is observed for the 350 nm Bi2Te3 film. Furthermore, it can be shown that with increasing film thickness, the annealing time has to be increased to maximize ZT.

Involved external institutions

Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. (IFW) / Leibniz Institute for Solid State and Materials Research Dresden DE Germany (DE)

How to cite

APA:

Naumochkin, M., Park, G.-H., Nielsch, K., & Reith, H. (2022). Study of the Annealing Effects of Sputtered Bi2Te3 Thin Films with Full Thermoelectric Figure of Merit Characterization. Physica Status Solidi-Rapid Research Letters, 16(4). https://doi.org/10.1002/pssr.202100533

MLA:

Naumochkin, Maksim, et al. "Study of the Annealing Effects of Sputtered Bi2Te3 Thin Films with Full Thermoelectric Figure of Merit Characterization." Physica Status Solidi-Rapid Research Letters 16.4 (2022).

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