Matthew J. Bierman
Graduate Student, Materials Chemistry
Department of Chemistry
University of Wisconsin-Madison
Biographical Sketch
B.S. University of Wisconsin-La Crosse, Chemistry and Physics, 2003
PhD University of Wisconsin-Madison, 2004-Present
Research
My project involves the synthesis and characterization of rare earth chalcogenide nanowires like EuO. EuO is a concentrated ferromagnetic semiconductor that is useful for studying the underlying physics of spintronics. I've suceeded in synthesizing the first nanorods of EuO through a solution synthesis of Eu(OH)3 and subsequent solid state conversion. Since then, I've studied the magnetic and magneto-optical properties of these nanorods via SQUID (Superconducting QUantum Interference Device) magnetometry and magnetic circular dichroism (MCD), and I'm working on making spintronic devices from them.
Additionally, I have been working on the synthesis and exploitation of PbS and PbSe nanowires for photovoltaic applications. PbS/PbSe nanocrystals have recently been shown to have up to an 800% quantum efficency in absorbing light; send one photon in, get as many as 8 electrons out! The technological limitation is in the short carrier lifetimes. These 8 charges need to be collected fast -- in as little as picoseconds -- or they will recombine. Using a nanowire should allow for the carriers to be collected along the wire, and generated from the other 2 dimensions which are quantum confined.
Selected Publications and Presentations
1) Bierman, M.J..; Lau, Y.K.A.; Jin, S.; Hyperbranched PbS and PbSe Nanowires and the Effect of Hydrogen Gas on Their Synthesis, Nano Lett. 7 (2007) 2907
2) Bierman, M.; Van Heuvelen, K.M.; Schmeisser, D.; Brunold, T.C.; Jin, S.; Ferromagnetic Semiconducting EuO Nanorods, Adv. Mater. 19 (2007) 2677
3) Szczech, J; Schmitt, A.L.; Bierman, M.J.; Jin, S.; Single-Crystal Semiconducting Chromium Disilicide Nanowires Synthesized via Chemical Vapor Transport, Chem. Mater. 19 (2007) 3238
4) 2006 MRS Fall National Meeting, (A) “Synthesis and Physical Properties of Ferromagnetic Semiconducting EuO Nanorods”, (B) “Nanorods of the Concentrated Ferromagnetic Semiconductor EuO: Synthesis and Physical Properties” M.J. Bierman and Song Jin, Boston, MA, November 27-December 2, 2006
5) 41st American Chemical Society Midwest Regional Meeting, “Synthesis and Physical Properties of Ferromagnetic Semiconducting EuO Nanorods”, M.J. Bierman and Song Jin, Quincy, IL, October 25-27, 2006
6) H.M. Kieler, M.J. Bierman, I.A. Guzei, P.J. Liska, R.W. McGaff, “Racemic iron(III) and cobalt(III) complexes containing a new pentadentate ‘‘helmet’’ phthalocyaninato ligand”, Chem. Comm., 3326-8, 2006
7) A.L. Schmitt, M.J. Bierman, D. Schmeisser, F.J. Himpsel, Song Jin, “Synthesis and Properties of Single-Crystal FeSi Nanowires”, Nano Lett., 6, 1617-21, 2006
8) B.F. Klindworth, M.J. Bierman, A. Bush, The 2+1 Dimensional Q/Q-bar Potential in Fourth Order Color-Dielectric Transverse Lattice QCD”, Los Alamos National Laboratory High Energy Physics—Phenomenology, 2002
