Ramki Kalyanaraman is a faculty member with a joint appointment between Materials Science and Engineering & Chemical and Biomolecular Engineering. His current research interests are in the areas of advanced materials (for energy, sensing and electronics), nanomaterials and nanomanufacturing, thin films, and plasmonics.
Kalyanaraman earned his undergraduate degree in physics from the Indian Institute of Technology, Kharagpur in 1991; his Master of Technology degree in Materials Science from the Indian Institute of Technology, Kanpur in 1994; and his PhD in Materials Science and Engineering from North Carolina State University in 1998. His previous research has been in the area of oxide thin film growth (at NC State), ion implantation as a post-doctoral researcher with Oak Ridge National Lab and (then) Lucent Technologies Bell Labs, and in dynamic thin film assembly and laser dewetting as a Faculty in the Physics department at Washington University in St. Louis. He is the recipient of a 2005 National Science Foundation CAREER award and a 2011 UT College of Engineering Research Award.
Several of his collaborative research activities have been highlighted by news media and have appeared in the American Institute of Physics Virtual Journal of Nanoscience and Nanotechnology. His group's research appears in top journals (Adv Mat, PRB, PRL, Nat Mat, ACS Nano, Nanotechnology, Nanoscale), and he has over 200 papers and presentations and 35 invited talks at national and international conferences and universities. He has also organized international conference symposium and workshops, is an inventor, and has been involved in creating start-ups.
Advanced Functional Materials
We view advanced functional materials as those that show new, improved, or unusual behaviors and could be potentially used in future technologies that are useful to society. Our discoveries of such materials arise as a result of non-equilibrium processing, such as with nanosecond pulsed lasers, and design of materials for new functions. We focus our research on materials and devices for new and improved solar cells, magnetic applications, bio and chemical sensors, and electronics. A recent breakthrough that we reported in the journal Advanced Materials is our discovery that the oxidation rate of Ag nanoparticles can be substantially slowed down by galvanic effects in a bimetal configurations. Read more about this research topic.
This work has been funded by NSF.
While Si solar cell technology has been around for more than 30 years, the cost per watt of energy solar energy production continues to prohibit its widespread use. Many factors contribute to this, including cost of materials, complexity of fabrication, poor light absorption, poor efficiency at converting photons into energy, etc. Our research on solar energy is primarily focussed on harnessing the energy through innovations in Si ultrathin solar cells, inventing new and better solar cells such as hollow fiber based solar fabric, and improved light trapping coatings. We reported recently in Nanomaterials and Energy that Ni-silicide nanoparticles increase light absorption in Si by dramatic amounts. Read more about this research topic.
This work has been funded by NSF.
Plasmonics and Optics
Plasmonics is the field that deals with the resonant interaction of light with materials that can sustain collective and coherent electron oscillations, such as metals. This field is very important towards technologies in biosensing, chemical sensing, waveguiding, solar energy harvesting, sub-diffraction limited optics, etc. Currently there are only two metals with useful and practical ambient air visible light plasmonics properties, Au and Ag. However, Au is expensive and, though Ag is much superior to Au, it degrades rapidly in ambient air and other corrosive environments. So our plasmonics work is aimed at discovering new materials for visible wavelength applications by a combination of materials design and modeling, synthesis, and characterization. We reported recently in Advanced Materials that Ag-Co bimetal nanoparticles have at least a 10 times longer useful plasmon lifetime air as compared to pure Ag. Read more about this research topic.
This work has been funded by various centers.
While a number of materials show new and useful behavior due to their nanoscale size, it is challenging to translate them into real applications because real world devices are generally macroscopic in dimensions. Therefore, it is critical to be able to nanomanufacture the useful material in a desired fashion. We are focussed on the use of self-organization, which is the pathway often seen in nature, to build nanoscale materials. In a recent work with collaborators, we developed the experimental and theoretical foundations to manufacture many new and different types of nanostructures by bilayer liquid self-organizationin, as reported in ACS Nano and Physics of Fluids. Read more about this research topic.
This work has been funded by NSF.
PhD, North Carolina State University, Raleigh: Advanced materials for energy, thin films, nanomaterials, nanomanufacturing, sensing and electronics, self-organization, laser processing, plasmonics.
- Member of MRS, APS, SPIE, OSA, TMS professional societies.
- Co-organizer: MRS Symposium “Self-assembly of Nanostructures by Photon and Ion Beams: Fundamentals and Applications,” 2006.
- Co-organizer International Workshop on “Nanopatterning via Ions, Photon beams and Epitaxy,” 2007.
Awards and Recognitions
- 2005 NSF CAREER Award
- 1999 CRADA joint post-doctoral fellowship, ORNL and Lucent Bell Labs
- 1998 Elected to Phi Kappa Phi Honor Society
- R. Sachan, V. Ramos, A. Malasi, S. Yadavali, B. Bartley, H. Garcia, G. Duscher, and R. Kalyanaraman, "Oxidation-resistant Ag nanostructures for ultrastable plasmonic applications," Advanced Materials, DOI: 10.1002/adma.201204920, (2013).
- R . Sachan, C.M. Gonzalez, O. Dyck, Y. Wu, H. Garcia, P.D. Rack, G. Duscher, R. Kalyanaraman, "Optical absorption enhancement within ultra-thin Si films by embedded silicide nanostructures," Nanomaterials and Energy, 2, 11-19, (2013).
- H. Krishna, N. Shirato, S. Yadavali, R. Sachan, J. Strader, R. Kalyanaraman, "Self-Organization of Nanoscale Multilayer Liquid Metal Films: Experiment and Theory," ACS Nano, 5, 470 - 476 (2011).
- J. Trice, C. Favazza, D. Thomas, R. Kalyanaraman, R. Sureshkumar, "Novel self-organization mechanism in ultrathin liquid films: theory and experiment," Phys. Rev. Lett. 101, 017802 (2008).
- M. Vasudevan, E. Buse, D. Lu, H. Krishna, R. Kalyanaraman, A. Shen, B. Khomami, and R. Sureshkumar, "Irreversible nanogel formation in surfactant solutions by microporous flow," Nature Materials, 9, 436 (2010).
- R. Kalyanaraman, "Nucleation energetics during homogeneous solidification in elemental metallic liquids," J. Appl. Phys. 104, 033506, (2008). Free AIP access at http://link.aip.org/link/?JAP/104/033506.
- J. Trice, D. Thomas, C. Favazza, R. Sureshkumar, and R. Kalyanaraman, "Pulsed-laser-induced dewetting in nanoscopic metal films: Theory and experiments," Phys. Rev. B, 75, 235439 (2007).
- H. Garcia, J. Trice, R. Kalyanaraman, and R. Sureshkumar, "Self consistent determination of plasmonic resonances in ternary nanocomposites," Phys. Rev. B, 75, 045439 (2007).
- W. Zhang, C. Zhang and R. Kalyanaraman, "Dynamically ordered thin film nanoclusters," J. Vac. Sci. Tech. B 23, L5-L8 (2005).
- S.P. Withrow, C.W. White, J.D. Budai, L.A. Boatner, K.D. Sorge, J.R. Thompson, and R. Kalyanaraman, "Ion beam synthesis of magnetic Co-Pt alloys in Al2O3," J. Mag. Mag. Mat. 260, 319-329 (2003).
- R. Kalyanaraman, V.C. Venezia, L. Pelaz, T.E. Haynes, H.-J.L. Gossmann and C.S. Rafferty, "Enhanced Low Temperature Activation of B in Si," Appl. Phys. Lett. 82, 215-217 (2003).
- R. Kalyanaraman, T.E. Haynes, O.W. Holland, H.-J.L. Gossmann, C.S. Rafferty, and G.H. Gilmer, "Binding energy of vacancies to clusters formed in Si by high-energy ion implantation," Appl. Phys. Lett. 79, 1983-1985 (2001).
A new process for fabrication of semiconductor devices on Si-on-insulator substrates V.C. Venezia, L. Pelaz, R. Kalyanaraman, T.E. Haynes, H.-J.L. Gossmann, and C.S. Rafferty, US Patent # US Pat No 6,632,728.