Issue 40, 2015

Carrier dilution in TiSe2 based intergrowth compounds for enhanced thermoelectric performance

Abstract

Synthesis and electrical properties of kinetically stabilized (PbSe)1+δ(TiSe2)n thin-film intergrowths are reported for 1 ≤ n ≤ 18. A linear increase in the c-lattice parameter of the intergrowth is observed as n is increased and the slope is consistent with the inclusion of an additional TiSe2 structural unit as n is incremented by 1 and the observed intercept is consistent with the expected thickness of a PbSe bilayer. The charge donated to the TiSe2 constituent from the PbSe is diluted across more layers as n is increased, leading to a systematic increase in the Seebeck coefficient. The room temperature resistivity values of the reported compounds are all on the order of 10−5 Ω m and depend on defect densities that affect the mobility, making the magnitude of the resistivity less sensitive to n. The temperature dependence is metallic for large n, with a slight upturn at low temperatures due to localization of carriers for small n values. The power factor increases with n, including the highest reported for chalcogenide misfit layered and related compounds, showing that nanostructuring and modulation doping are an effective means of tuning the power factor of thermoelectric intergrowth materials. Since these compounds have very low thermal conductivity due to structural anisotropy and misregistration between intergrowth constituents, this suggests that varying their nanoarchitecture is a promising approach to obtain high values of zT.

Graphical abstract: Carrier dilution in TiSe2 based intergrowth compounds for enhanced thermoelectric performance

Article information

Article type
Paper
Submitted
31 may. 2015
Accepted
16 jul. 2015
First published
16 jul. 2015

J. Mater. Chem. C, 2015,3, 10451-10458

Carrier dilution in TiSe2 based intergrowth compounds for enhanced thermoelectric performance

S. R. Bauers, D. R. Merrill, D. B. Moore and D. C. Johnson, J. Mater. Chem. C, 2015, 3, 10451 DOI: 10.1039/C5TC01570G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements