Reduced Thermal Conductivity in Silicon Thin-Films via Vacancies


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An experimental method is defined that reduces the thermal conductivity in Si films by ~90 % compared to control samples, while keeping the thermoelectric power factor almost unchanged. This is done by creating vacancy-rich films via high-energy self-implantation of Si, followed by rapid-thermal annealing. TCAD simulations suggest that this approach is scalable for application in thin-film thermoelectric generators, as an alternative to more expensive and less Earth-abundant materials such as bismuth telluride. This approach to Si thermoelectrics could be straight-forward for scale-up to thin-film device dimensions, something that is a major challenge for other methods used for Si thermal conductivity reduction.



Solid State Phenomena (Volume 242)

Edited by:

P. Pichler




N. M. Wight and N. S. Bennett, "Reduced Thermal Conductivity in Silicon Thin-Films via Vacancies", Solid State Phenomena, Vol. 242, pp. 344-349, 2016

Online since:

October 2015




[1] L. Weber and E. Gmelin, Transport properties of silicon. Appl. Phys. A 53 (1991) 136–140.

[2] A. I. Hochbaum, R. Chen, R. D. Delgado, W. Liang, E. C. Garnett, M. Najarian, A. Majumdar, and P. D. Yang, Enhanced thermoelectric performance of rough silicon nanowires, Nature 451 (2008) 163–167.


[3] A. I. Boukai, Y. Bunimovich, K. J. Tahir, J. Yu, W. A. Goddard, and J. R. Heath, Silicon nanowires as efficient thermoelectric materials, Nature 451 (2008) 168–171.


[4] J. Tang, H. Wang, D. H. Lee, M. Fardy, Z. Huo, T. P. Russell, and P. Yang, Holey silicon as an efficient thermoelectric material, Nano Lett. 10 (2010) 4279-4283.


[5] J. -K. Yu, S. Mitrovic, D. Tham, J. Varghese, and J. R. Heath, Reduction of thermal conductivity in phononic nanomesh structures, Nature Nanotechnology 5 (2010) 718–721.


[6] Y. Lee, S. Lee, and G. S. Hwang, Effects of vacancy defects on thermal conductivity in crystalline silicon: A nonequilibrium molecular dynamics study, Phys. Rev. B 83 (2011) 125202.


[7] P. -H Huang, and C. -M. Lu, Effects of Vacancy Cluster Defects on Electrical and Thermodynamic Properties of Silicon Crystals, The Scientific World Journal (2014) 863404.


[8] T. Wang, G. K. H. Madsen, and A. Hartmaier, Atomistic study of the influence of lattice defects on the thermal conductivity of silicon, Modelling Simul. Mater. Sci. Eng. 22 (2014) 035011.


[9] P. Pichler. Intrinsic Point Defects, Impurities, and Their Diffusion in Silicon. (Spring-Verlag, New York, 2004).

[10] B. Nielsen, O. W. Holland, T. C. Leung, and K. G. Lynn, Defects in MeV Si‐implanted Si probed with positrons, J. Appl. Phys. 74 (1993) 1636.


[11] Athena User's Manual. November 12, 2014. Silvaco Inc.

[12] A. J. Smith, PhD Thesis, The Formation of Ultra-shallow p-type Junctions using Vacancy Engineering, University of Surrey, United Kingdom, (2006).

[13] S. Coffa, and S. Libertino, Room-temperature diffusivity of self-interstitials and vacancies in ion-implanted Si probed by in situ measurements, Appl. Phys. Lett. 73 (1998) 3369.


[14] P. Pichanusakorn, and P. Bandaru, Nanostructured thermoelectrics. Materials Science and Engineering R 67 (2010) 19-63.


[15] D. G. Cahill, S. K. Watson, and R. O. Pohl, Lower limit to the thermal conductivity of disordered crystals. Phys. Rev. B 46 (1992) 6131–6140.


[16] P. G. Coleman, D. Nash, C. J. Edwardson, A. P. Knights, and R. M. Gwilliam, The evolution of vacancy-type defects in silicon-on-insulator structures studied by positron annihilation spectroscopy. J. Appl. Phys. 110 (2011) 016104.


[17] P. G. Coleman, Activation energies for vacancy migration, clustering and annealing in silicon. Journal of Physics: Conference Series 265 (2011) 012001.


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