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Carrier Lifetime Enhancement in a Tellurium Nanowire/PEDOT:PSS Nanocomposite by Sulfur Passivation

Published online by Cambridge University Press:  20 February 2015

James N. Heyman ,
Ayaskanta Sahu ,
Nelson E. Coates ,
Brittany Ehmann  and
Jeffery J. Urban
James N. Heyman
Affiliation:
Physics Department, Macalester College, St. Paul, MN 55105, USA
Ayaskanta Sahu
Affiliation:
The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
Nelson E. Coates
Affiliation:
The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
Brittany Ehmann
Affiliation:
Physics Department, Macalester College, St. Paul, MN 55105, USA
Jeffery J. Urban
Affiliation:
The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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Abstract

We report static and time-resolved terahertz (THz) conductivity measurements of a highperformance thermoelectric material containing tellurium nanowires in a PEDOT:PSS matrix. Composites were made with and without sulfur passivation of the nanowires surfaces. The material with sulfur linkers (TeNW/PD-S) is less conductive but has a longer carrier lifetime than the formulation without (TeNW/PD). We find real conductivities at f = 1THz of σTeNW/PD = 160 S/cm and σTeNW/PD-S = 5.1 S/cm. These values are much larger than the corresponding DC conductivities, suggesting DC conductivity is limited by structural defects. The free-carrier lifetime in the nanowires is controlled by recombination and trapping at the nanowire surfaces. We find surface recombination velocities in bare tellurium nanowires (22m/s) and TeNW/PD-S (40m/s) that are comparable to evaporated tellurium thin films. The surface recombination velocity in TeNW/PD (509m/s) is much larger, indicating a higher interface trap density.

Keywords

thermoelectricelectrical propertiesTe
Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 1742: Symposium BB – Molecular, Polymer and Hybrid Materials for Thermoelectrics , 2015 , mrsf14-1742-bb04-02
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Chen, Z. G., Han, G., Yang, L., Cheng, L. N. and Zou, J., Prog. Nat. Sci-Mater. 22 (6), 535-549 (2012).CrossRefGoogle Scholar
Pichanusakorn, P. and Bandaru, P., Mat. Sci. Eng. R 67 (2-4), 19–63 (2010).CrossRefGoogle Scholar
Snyder, G. J. and Toberer, E. S., Nature Materials 7 (2), 105-114 (2008).CrossRefGoogle Scholar
Coates, N. E., Yee, S. K., McCulloch, B., See, K. C., Majumdar, A., Segalman, R. A. and Urban, J.J., Adv. Mater. 25 (11), 1629-1633 (2013).CrossRefGoogle Scholar
See, K. C., Feser, J. P., Chen, C. E., Majumdar, A., Urban, J. J. and Segalman, R. A., Nano Letters 10 (11), 4664-4667 (2010).CrossRefGoogle Scholar
Yee, S. K., Coates, N. E., Majumdar, A., Urban, J. J. and Segalman, R. A., Phys. Chem. Chem. Phys. 15 (11), 4024-4032 (2013).CrossRefGoogle Scholar
Beard, M. C., Turner, G. M. and Schmuttenmaer, C. A., J. Phys. Chem. 106, 7146–7159 (2002).CrossRefGoogle Scholar
Heyman, J. N., Alebachew, B. A., Kaminski, Z. S., Nguyen, M. D., Coates, N. E. and Urban, J. J., Appl. Phys. Lett. 104 (14) (2014).CrossRefGoogle Scholar
Bohren, C. F. and Huffman, D. R., Absorption and scattering of light by small particles. (Wiley, New York, 1983).Google Scholar
Pankove, J. I., Optical Processes in Semiconductors, 2nd ed. (Dover Publications, 2010), 162.Google Scholar
Shyamprasad, N. G., Champness, C. H. and Shih, I., Infrared Phys. 21, 45–52 (1980).CrossRefGoogle Scholar