THERMAL AND THERMOELECTRIC TRANSPORT FACILITIES

Our research investigations are enabled by a variety of techniques that we employ for characterization of transport properties and thermoelectric energy conversion in thin-films, nanowires, interfaces, and bulk nanomaterials (shown below with selected references):

· 3w method for anisotropic thin film thermal conductivity characterization (film-on-substrate systems). [1]

· 3w and DC Joule heating thermometry for suspended nano/microwire and film structures. [2]

· A technique using microfabricated test structures for electrical conductivity and Seebeck coefficient characterization of drop-casted films. [3]

· A photo-thermoelectric technique for anisotropic thin-film thermal diffusivity and interface thermal resistivity characterization. [4]

· A scanning hot microprobe system for quantitative spatially resolved measurements of thermal conductivity and Seebeck coefficient. [5]

· A scanning electrical microprobe for electrical conductivity and interface electrical resistivity characterization. [6]

· Cox & Strack based technique for thin-film electrical conductivity and interface electrical resistivity measurements. [7]

· Van der Pauw and Hall based techniques for electrical conductivity, mobility, and carrier concentration measurements. [8]

· A technique using etched MESA structures for cross-plane electrical characterization of thin films and their interface electrical resistivity. [9]

· Steady state setups for characterization of thermal conductivity, interface thermal resistivity, and Seebeck coefficient adaptable to various sample sizes. [10]

· Enhanced Harman based techniques for ZT characterization and thermal conductivity, electrical conductivity and Seebeck coefficient measurements of thermoelectric materials. [11]

· A ZEM instrument for Seebeck and electrical conductivity characterization of bulk materials and thin film-on substrate samples from cryogenic to high temperatures.

· A vacuum chamber to perform temperature dependent characterization from cryogenic to high temperatures.

· DAQ & Control systems for characterization of thermal & thermoelectric systems.

· We adapt our techniques to a variety of sample systems and dimensions.

Selected References

1. Borca-Tasciuc, T., Kumar, A. R., and Chen, G, “Data Reduction in 3w Method for Thin-Film Thermal Conductivity Determination,” Review of Scientific Instruments, Vol. 72, 2139-2147, 2001. (PDF); Liu, W. L., Borca-Tasciuc, T., Chen, G., Liu, J.L., and Wang, K. L. ”Anisotropic Thermal Conductivity of Ge-Quantum Dot and Symmetrically Strained Si/Ge superlattices,” Journal of Nanoscience and Nanotechnology, Vol. 1, 39-42, 2001. (PDF); H. R. Fard, N. Becker, A. Hess, K. Pashayi1, T. Proslier, M. Pellin and T. Borca-Tasciuc, “Thermal Conductivity of Er⁺³:Y₂O₃ films grown by Atomic Layer Deposition,” Applied Physics Letters, Vol. 103, 193109 1-5, 2013 (Link)

2. Borca-Tasciuc, T., Vafaei, S., Borca-Tasciuc, D.-A., Wei, B. Q, Vajtai, R., and Ajayan, P., “Anisotropic Thermal Diffusivity of aligned multiwall carbon nanotube arrays” Journal of Applied Physics, Vol. 98, 054309, 2005. (PDF); R. J. Mehta, C. Karthik, W. Jiang, B. Singh, Y. Shi, T. Borca-Tasciuc, and G. Ramanath, ”High Electrical Conductivity Antimony Selenide Nanocrystals and Assemblies” Nanoletters, Vol. 10, 4417–4422, 2010. (PDF); Karthik, C., Jiang, W., Mehta, R. J., Castillo, E. E., and Borca-Tasciuc, T., and Ramanath, G, “Threshold Conductivity Switching in Sulfurized Antimony Selenide Nanowires,” Applied Physics Letters, Vol. 99, 103101, 2011. (PDF).

3. Purkayastha, A., Lupo, F., Kim, S., Borca-Tasciuc, T., and Ramanath, G., “Low-temperature templateless synthesis of single-crystal bismuth telluride nanorods,” Advanced Materials, Vol. 18, 496-500, 2006. (PDF); Purkayasthaa, A., Ganesana, P. G., Kumara, A., Kim, S., Borca-Tasciuc, T., and Ramanath, G., ”Molecularly-protected bismuth telluride nanoparticles: microemulsion synthesis, and thermoelectric transport properties, ”Advanced Materials, Vol. 18, 2958-2963, 2006. (PDF).

4. Borca-Tasciuc, T. and Chen, G., “Thin-film Thermophysical Property Characterization by Scanning Laser Thermoelectric Microscope,” International Journal of Thermophysics, Vol. 19, 557-567, 1998. (PDF); Borca-Tasciuc, T., Vafaei, S., Borca-Tasciuc, D.-A., Wei, B. Q, Vajtai, R., and Ajayan, P., “Anisotropic Thermal Diffusivity of aligned multiwall carbon nanotube arrays,” Journal of Applied Physics, Vol. 98, 054309, 2005. (PDF); Borca-Tasciuc, T., Borca-Tasciuc, D.-A., and Chen G., “A Photothermoelectric Technique for Anisotropic Thermal Diffusivity Characterization of Nanowire/Nanotube Composites,” IEEE Transactions on Components and Packaging Technologies, Vol. 30, 609-617, 2007. (PDF).

5. Y. Zhang, C. L. Hapenciuc, E. E. Castillo, T. Borca-Tasciuc, R. J. Mehta, C. Karthik, and G. Ramanath, “A Microprobe Technique for Simultaneously Measuring Thermal Conductivity and Seebeck Coefficient of Thin Films,”Applied Physics Letters, Vol. 96, 062107, 2010. (PDF); Y. Zhang, E. Castillo, R. Mehta, G. Ramanath, and T. Borca-Tasciuc, “A Non-Contact Thermal Microprobe for Local Thermal Conductivity Measurement,” Review of Scientific Instruments, Vol. 82, 024902, 2011. (PDF); M. M. Rojo, J. Martín, S. Grauby, T. Borca-Tasciuc, S. Dilhaire and M. Martin-Gonzalez, “Decrease in thermal conductivity in polymeric P3HT nanowires by size-reduction induced by crystal orientation: new approaches towards thermal transport engineering of organic materials,” Nanoscale, Vol. 6, 7858-7865, 2014 (Link); A. A. Wilson, M. Muñoz Rojo, Begoña Abad, J. Andrés Perez, J. Maiz, J. Schomacker, M. Martín-Gonzalez, D.-A. Borca-Tasciuc and T. Borca-Tasciuc, “Thermal conductivity measurements of high and low thermal conductivity films using a scanning hot probe method in the 3ω mode and novel calibration strategies,” Nanoscale, Accepted Manuscript, 2015 (Link).

6. Devender, R. J. Mehta, K. Lofgreen, R. Mahajan, M. Yamaguchi, T. Borca-Tasciuc and G. Ramanath, “Effects of chemical intermixing on electrical and thermal contact conductances at metallized bismuth and antimony telluride interfaces,” Journal of Vacuum Science and Technology A Vol. 33, 020605 1-6, (2015) (Link).

7. Devender, R. J. Mehta, K. Lofgreen, R. Mahajan, M. Yamaguchi, T. Borca-Tasciuc and G. Ramanath, “Effects of chemical intermixing on electrical and thermal contact conductances at metallized bismuth and antimony telluride interfaces,” Journal of Vacuum Science and Technology A Vol. 33, 020605 1-6, (2015) (Link).

8. Rutvik J. Mehta, Yanliang Zhang, Chinnathambi Karthik, Binay Singh, Richard W. Siegel, Theodorian Borca-Tasciuc & Ganpati Ramanath, “A New Class of Doped Nanobulk High-Figure-of-Merit Thermoelectrics by Scalable Bottom-up Assembly” Nature Materials, Vol. 11, 233-240, 2012 (Link); Yanliang Zhang, Rutvik J. Mehta, Matthew Belley, Liang Han, Ganpati Ramanath, and Theodorian Borca-Tasciuc, “Lattice Thermal Conductivity Diminution and High Thermoelectric Power Factor Retention in Nanoporous Macroassemblies of Sulfur-Doped Bismuth Telluride Nanocrystals,” Applied Physics Letters, Vol. 100, 1193113 1-4, 2012 (PDF).

9. M. Muñoz Rojo, C. Vicente Manzano, D. Granados, M. Rodriguez Osorio, T. Borca-Tasciuc, and M. Martin-Gonzalez, “High electrical conductivity in out of plane direction of electrodeposited Bi₂Te₃ films,”
AIP Advances, Accepted Manuscript, 2015 (Link - coming soon).

10. Rutvik J. Mehta, Yanliang Zhang, Chinnathambi Karthik, Binay Singh, Richard W. Siegel, Theodorian Borca-Tasciuc & Ganpati Ramanath, “A New Class of Doped Nanobulk High-Figure-of-Merit Thermoelectrics by Scalable Bottom-up Assembly” Nature Materials, Vol. 11, 233-240, 2012 (Link); Kamyar Pashayi, Hafez Raeisi Fard, Fengyuan Lai, Sushumna Iruvanti, Joel Plawsky, and Theodorian Borca-Tasciuc, “High Thermal Conductivity Epoxy-Silver Composites Based on Self-Constructed Nanostructured Metallic Networks,” Journal of Applied Physics, Vol. 111, 104310 1-6, 2012 (PDF); I. Seshadri, T. Borca-Tasciuc, P. Keblinski and G. Ramanath, “Interfacial thermal conductance-rheology nexus in metal-contacted nanocomposites,” Applied Physics Letters, Vol. 103, 173113 1-4, 2013 (Link); K. Pashayi, H. R. Fard, F. Lai, S. Iruvanti, J. Plawsky and T. Borca-Tasciuc, “Self-Constructed Tree-Shape High Thermal Conductivity Nanosilver Networks in Epoxy,” Nanoscale, Vol. 6, 4292-4296, 2014 (Link).

11. E. E. Castillo, C. L. Hapenciuc, and T. Borca-Tasciuc, “Thermoelectric Characterization by Transient Harman Method Under Non-Ideal Contact and Boundary Conditions,” Review of Scientific instruments, Vol. 81, 044902, 2010. (PDF); M. M. Rojo, J. J. Romero, D. Ramos, D. Borca-Tasciuc, T. Borca-Tasciuc and M. Martín-González, “Modeling of transient thermoelectric transport in Harman method for films and nanowires,” International Journal of Thermal Science, Vol. 89, 193-202, 2015 (Link).