Current Research

Characterization of Novel Thin Films for Use in Solar Cells
In collaboration with Christopher Exstrom from UNK, Natale Ianno and Rodney Soukup from the Electrical Engineering department at UNL, we are studying the optical characteristics of amorphous thin films of Silicon, silicon-germanium alloys, germanium-carbide alloys, and now we are working on some very novel materials related to Copper Indium Selenide films. We hope to create high-efficiency materials for solar energy conversion.
We have added the capability of high resolution surface Raman microscopy to the research project. This technique will allow us to understand both the composition and behavior of the materials we create. In addition, we are able to create nanoparticulate precursers (see Dr. Exstrom's Research) that can be annealed to create thin films.

Laser Spectroscopy/ Instrument Development
With the support of the University of Nebraska Foundation, we have an ongoing project that is integrating the use of lasers and laser spectroscopy in the chemistry curriculum. We have developed several laboratories for general chemistry that use a novel modular laser setup for the measurement of sulfate ion concentration in natural waters using laser nephelometry, the determination of rate order and rate constants for the acid-catalyzed hydrolysis of sucrose, and the determination of denaturation kinetics of proteins by free-radicals.
We have also constructed two advanced instruments: a spectrofluorimeter with CCD detection that uses either broadband or laser excitation sources and a time-resolved laser spectrofluorimeter, also capable of transient absorption measurements. Recent work with these instruments has included the investigation of porphyrin and metal-porphyrin fluorescence kinetics.

Recent Key Publications

C. Kamler, N. J. Ianno, J. Huguenin-Love, R. J. Soukup, J. Olejnicek, S. A. Darveau, and C. L. Exstrom, “Thin Films Formed by Selenization of CuIn_xB_1-x Precursors in Se Vapor”, Solar Energy Materials and Solar Cells, submitted Sep 2007.

T. Baynard, A. C. Reber , R. F. Niedziela, S. A. Darveau, B. Prutzman, and R. S. Berry, “Electron-atom superelastic scattering in magnesium at milli-electron volt energies,” J. Phys. Chem. A 111, 12487-12494 (2007).

N. J. Ianno, R. J. Soukup, C. L. Exstrom, and S. A. Darveau, “Copper-Indium-Boron-Diselenide Absorber Materials,”. Material Research Society Symposium Proceedings 1012, Y03.21. (2007).

R. J. Soukup, N. J. Ianno, J. S. Schrader, C. L. Exstrom, S. A. Darveau, R. N. Udey, and V. L. Dalal, “Thin Films of GeC Deposited Using a Unique Hollow Cathode Sputtering Technique,” Solar Energy Materials and Solar Cells 90, 2338-2345 (2006).

R. J. Soukup, N. J. Ianno, S. A. Darveau, and C. L. Exstrom, “Thin Films of A-SiGe:H With Device Quality Properties Prepared By a Novel Hollow Cathode Deposition Technique,” Solar Energy Materials and Solar Cells 87, 87-98 (2005).

R. J. Soukup, N. J. Ianno, S. A. Darveau, and C. L. Exstrom, “Optical and Electronic Characterization of a-SiGe:H Thin Films Prepared by a Novel Hollow Cathode Deposition Technique,” Material Research Society Symposium Proceedings. 808, A9.4.1 ( 2004).

Scott A. Darveau, Jessica Mueller, April Vaverka, Cheri Barta, Anthony Fitch, Jessica Jurzenski, and Yvonne Gindt, “A Modular Laser Apparatus for Polarimetry, Nephelometry, and Fluorimetry in General Chemistry,” J. Chem. Educ. 81 (3) 401-405 (2003).

S. A. Darveau and R. S. Berry, “Superelastic Collisions [e+Mg^*] Following Resonant, 2-Photon Ionization of Mg Atoms,” Proceedings of the Ninth International Symposium on Resonance Ionization Spectroscopy, Ed. by J. C. Vickerman, I. Lyon, N. P. Lockyer, and J. E. Parks, American Institute of Physics, 1998, p. 253.