Rachel
Rachel S. Selinsky
Graduate Student, Materials Chemistry
Department of Chemistry
University of Wisconsin-Madison
Biographical Sketch
B.A. Williams College, Chemistry and Studio Art, 2006
PhD University of Wisconsin-Madison, 2006-Present
Research
My project involves the solution synthesis and characterization of EuS, PbSe, and PbS nanocrystals for device applications. My primary nanocrystalline material is EuS, an intrinsic magnetic semiconductor. I have been developing and characterizing a library of single source euriopium dithiocarbamate precursors to control the quality, size, and morphology of EuS nanocrystals.
Figure 1. TEM images of EuS nanocrystals
Although the magnetic properties of EuS are interesting, device applications are not possible due to its Curie temperature of 16.5 K. In order to increase this temperature, I have been attempting doping with Gd, a known EuS magnetic dopant in the bulk. Additionally, because the ligands coating nanocrystals has been shown to strongly influence their magnetic and electronic properties as well as change their solubility I have been studying the effects of electron withdrawing and donating ligands on the magnetic properties of EuS nanocrystals. Finally, I have been using XMCD, an element specific magnetic measurement, to investigate the magnetism in EuS.
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Figure 1. TEM images of PbSe nanocrystals (left) and PbS nanocrystals (right)
PbSe and PbS have been shown to potentially have quantum efficiencies much greater than 100% making them useful for photovoltaic applications. In addition to high quantum efficiencies, due to quantum confinement the bandgaps of these materials can be easily tuned by changing the size of the particles. I am working in collaboration with chemists specializing in surface characterization and modification and chemists specializing in multi dimensional spectroscopy to investigate these properties.
