Sergei A. Ivanov

Staff Chemist, Center for Integrated Nanotechnologies
Science Thrust: Nanophotonic and Optical Nanomaterials

Phone: 505-284-7971
Fax: 505-284-7778
 ivanov@lanl.gov

MPA-CINT, MS K771
Los Alamos National Laboratory
Los Alamos, NM 87545


 

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Research

The preparation of “high-quality” semiconductor, metal, and magnetic nanocrystals. We define success in part by our ability to control size dispersity, particle crystallinity, particle stability, and particle optical/electronic/magnetic properties with target functionality in mind. We strive to understand the effects of particle size, particle shape, and particle surface structure and functionalization on nanocrystal properties and, subsequently, to optimize these properties. The primary focus is on the preparation of new compositions (core and core/shell materials; UV to visible to infrared absorbers/emitters; ferromagnetic to superparamagnetic nanoparticles, etc.), new shapes (isotropic to highly anisotropic), and composite materials (e.g., high-density nanocrystal/sol-gel processible blends), as well as self- and directed-assembly of films and composite structures. Nanocrystal chemical-precursor development and ligand/surfactant development are pursued when necessary. We are also interested in the understanding the origins for desirable properties of obtained nanosystems and means of their control utilizing quantum chemical calculations with models of the synthesized nanostructures.

Selected Publications

  • S. A. Ivanov, R. V. Nichiporuk, E. G. Mednikov, and L. F. Dahl, “First high-nuclearity thallium-palladium carbonyl phosphine clusters, [Tl2Pd12(CO)9(PEt3)9]2+, and its initial mistaken identity as the unknown Au2Pd12 analogue: structure-to-synthesis approach concerning its formation” J.Chem.Soc., Dalton Trans. 4116 (2002).
  • V. I. Klimov, S. A. Ivanov, J. Nanda, M. Achermann, I. Bezel, J. A. McGuire, A. Piryatinski “Single-exciton optical gain in semiconductor nanocrystals” Nature 447, 441(2007).
  • S. A. Ivanov, A. Piryatinski, J. Nanda, S. Tretiak, K. R. Zavadil, W. O. Wallace, D. Werder, and V. I. Klimov “Type-II Core/Shell CdS/ZnSe Nanocrystals: Synthesis, Electronic Structures, and Spectroscopic Properties” J. Am.Chem.Soc.129(38), 11708 (2007).
  • S. Goel, K. A. Velizhanin, A.Piryatinski, S. Tretiak, S. A. Ivanov “DFT studies of ligand binding to small gold clusters” J. Phys. Chem. Lett.1, 927(2010).
  • S. A. Ivanov, M. Achermann “Spectral and Dynamic Properties of Excitons and Biexcitons in Type-II Semiconductor Nanocrystals” ACS Nano 4 (10), 5994 (2010).
  • E. G. Mednikov, S. A. Ivanov, and L. F. Dahl “CO-Induced Formation of an Interpenetrating Bicuboctahedral Au2Pd18 Kernel in Nanosized Au2Pd28(CO)26(PEt3)10: Formal Replacement of an Interior (μ12-Pd)2 Fragment in the Corresponding Known Isostructural Homopalladium Pd30(CO)26(PEt3)10 with Nonisovalent (μ12-Au)2 and Resulting Experimental/Theoretical Implications” Inorg. Chem. 50(22), 11795-11806 (2011).
  • S. A. Ivanov, I. Arachchige, C. Aikens “Density Functional Analysis of Geometries and Electronic Structures of Gold-Phosphine Clusters. The Case of Au4(PR3)42+ and Au4(μ2-I)2(PR3)4.” J. Phys. Chem. C 115(27), 8017-8031 (2011).
  • Arachchige, R. Soriano, C. D. Malliakas, S. A. Ivanov, M. Kanatzidis “Amorphous and Crystalline GeTe Nanocrystals” Adv. Func. Mater. 21(14), 2737-2743 (2011).
  • S. Kilina, K. A. Velizhanin, S. A. Ivanov, O. V. Prezhdo, S. Tretiak “Surface Ligands Increase Photoexcitation Relaxation Rates in CdSe Quantum Dots” ACS Nano 6(7), 6515-6524 (2012).

Selected User Projects

  • Multiexciton dynamics and binding energies in type-II semiconductor nanocrystals, Marc Achermann, The University of Massachusetts - Amherst
  • Composite Nanoparticles for Dual Magnetic-Bead-Labeling Biomolecules, Boris Khusid, New Jersey Institute of Technology         
  • Investigation of the electron and nuclear spin dynamics in semiconductor nanocrystals, Carlos Meriles, City College of New York