Issue 27, 2019, Issue in Progress

Nanostructured bulk Si for thermoelectrics synthesized by surface diffusion/sintering doping

Abstract

Nanostructured bulk silicon (bulk nano-Si) has attracted attention as an advanced thermoelectric (TE) material due to its abundance and low toxicity. However, oxidization will occur easily when bulk nano-Si is synthesized by a conventional method, which deteriorates the TE performance. Various methods to prevent such oxidation have been proposed but they need specific techniques and are thus expensive. Here, we propose a simple and cost-effective method named Surface Diffusion/Sintering Doping (SDSD) to synthesize bulk nano-Si for TEs. SDSD utilizes Si nanoparticles whose surface is coated with a native thin oxide layer. SDSD is composed of two steps, (1) a molecular precursor containing a doping element is added onto the oxide layer of Si nanoparticles and (2) the nanoparticles are sintered into a bulk state. During sintering, the doping element diffuses through the oxide layer forming conductive paths, which results in a high carrier concentration as well as high mobility. Furthermore, owing to the nanostructures, low lattice thermal conductivity (κlat) is also achieved, which is an ideal situation for TEs. In this study, we show that P-doped bulk nano-Si synthesized by SDSD shows good TE performance due to its high carrier concentration, high carrier mobility, and low κlat. Since SDSD takes advantage of oxidization, it is cost-effective and suitable for mass production to synthesize bulk nano-Si for TEs.

Graphical abstract: Nanostructured bulk Si for thermoelectrics synthesized by surface diffusion/sintering doping

Article information

Article type
Paper
Submitted
28 Mar 2019
Accepted
10 May 2019
First published
17 May 2019
This article is Open Access
Creative Commons BY license

RSC Adv., 2019,9, 15496-15501

Nanostructured bulk Si for thermoelectrics synthesized by surface diffusion/sintering doping

S. Tanusilp, N. Sadayori and K. Kurosaki, RSC Adv., 2019, 9, 15496 DOI: 10.1039/C9RA02349F

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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