Oleg Semenikhin Associate Professor B.Sc., M.Sc. 1988 Moscow Ph.D. 1993 Russian Academy of Sciences Office: ChB 067 Phone (Office): (519) 661-2111 ext 82858
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Electrochemistry, Materials Chemistry, Conducting Polymers, Photoelectrochemistry, Micro- and Nanotechnology
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Current Research Programs:
My current research can be roughly divided into two main areas:
- Electrochemistry, photoelectrochemistry and photovoltaic properties of conjugated organic polymers
- Scanning probe studies of the local inhomogeneity of conducting polymer-based materials.
In the first area, the goal of my research is to improve the photoefficiency of organic semiconductors based on polythiophenes and other conjugated polymers to be used in all-organic solar cells. We prepared and characterized a number of donor-acceptor thiophene-based polymers modified in the main chain with various electron-acceptor groups, such as bipyridine, biphenyl, phenanthroline, azine and silole. The best materials demonstrated a more than 5-fold increase in efficiency as compared to non-modified polybithiophene. Another research direction is post-polymerization modification of regular conducting polymers, such as polybithiophene, in order to improve their efficiency. Specifically, this approach yielded materials with the power conversion efficiency reaching 1%, which is the highest efficiency observed for a single-polymer photoelectrode not using the donor-acceptor architecture.
The other research area is the nanoscale inhomogeneity of conducting polymer-based materials. In our recent papers, we have shown using atomic-force microscopy (AFM), current-sensing AFM, Kelvin probe microscopy, and phase imaging that the inhomogeneity of both electropolymerized and spin-coated materials is related to the polydispersity of the polymer molecules in the electropolymerization or casting solution and the preferential deposition of higher molecular weight fractions during the early stages of the polymer phase formation. This conclusion is of a fundamental nature and opens up unique opportunities for creating high-quality materials by controlling the polydispersity of the starting polymer solutions.
Selected Publications:
30. Paul M. DiCarmine, Xin Wang, Brian L. Pagenkopf and Oleg A. Semenikhin, New Electropolymerized Poly(thienyl-silole)s for All-Polymer Solar Cells: Incorporation of Silole Results in Remarkable Enhancement of Photoefficiency Compared to Polybithiophene, Chemistry of Materials, submitted.
29. J. J. Tindale, H. Holm, M. S. Workentin and O. A Semenikhin, Electrochemistry and Photoelectrochemistry of Two Donor-Acceptor Polythiophene Polymers with Acceptor Moieties in the Main Chain, Journal of Electroanalytical Chemistry, in press (accepted October 1, 2007).
28. K.D. O’Neil and O.A. Semenikhin, AFM Phase Imaging of Electropolymerized Polybithiophene Films at Different Stages of their Growth, Journal of Physical Chemistry C, in press (doi:10.1021/jp074076u; accepted July 20, 2007).
27. P.M. Dicarmine and O.A. Semenikhin, Intensity Modulated Photocurrent Spectroscopy (IMPS) of Solid-State Polybithiophene-Based Solar Cells, Electrochimica Acta, special issue “Electroactive Materials”, in press (doi:10.1016/j.electacta.2007.06.057; accepted June 22, 2007).
26. K.D. O’Neil, B. Shaw, O.A. Semenikhin, On the Origin of Mesoscopic Inhomogeneity of Conducting Polymers, Journal of Physical Chemistry B, 2007, vol. 111, pp. 9253-9269.
