University of Nebraska Kearney

UNK Solar Energy and Nanoscience Research Group (SENRG)

Faculty Group Leaders:  Professors Christopher Exstrom and Scott Darveau

Links to:  SENRG Publications     SENRG Presentations     SENRG Funding 

Welcome to the SENRG webpage!  We are one of the world's most active undergraduate-based research groups in the development and study of nanocrystalline and thin-film materials with applications in photovoltaics and other electronics.  Our research projects are conducted in collaboration with colleagues in the University of Nebraska-Lincoln (UNL) Departments of Electrical Engineering and Mechanical Engineering; however, through $2,000,000 in external grant funding to the UNK SENRG as the primary awardee, we have built up the following independent laboratory capabilities:

Solvent-based nanomaterials synthesis, physical vapor deposition (for annealing and selenization), chemical bath deposition, dc sputtering (single-gun) for thin-film preparation, micro-Raman spectroscopy, ICP-OES for elemental analysis, and optical bandgap measurements (UV-vis and IR spectroscopy)

We are currently conducting research in several collaborative projects:

Development and Study of Chalcopyrite and Earth-Abundant Semiconductor Materials for High-efficiency Photovoltaic Solar Cells (collaborators:  Professors Rodney Soukup and Ned Ianno, UNL Department of Electrical Engineering, and Professor Jinsong Huang, UNL Department of Mechanical Engineering) --    Much of our effort focuses on solvent-based preparations of these materials in nanocrystalline form. The use of solvent in these preparations is an attractive, low-cost alternative to the existing high-vacuum techniques commonly employed in the solar cell industry. Efforts to maximize product compositional and structural control while minimizing reaction system cost and complexity have resulted in previously unreported nanocrystalline materials and preparation techniques.  Additional areas of investigation include studying effects of material structure and composition on Raman spectroscopic properties, chemical bath deposition of solar cell buffer materials, and nanomaterial processing for incorporation into prototype photovoltaic devices.

Center for Nanohybrid Functional Materials (CNFM) -- funding from Nebraska EPSCoR (NSF-RII).  CNFM includes fourteen investigators from five Nebraska colleges and universities and targets the discovery and exploitation of new sensing principles based upon the combination of 3-D ordered nanostructures and chemical or biochemical sensing elements. Research within CNFM is focused within three complementary and mutually supporting clusters.  The role of SENRG is to study the solvothermal preparation and structure control of metallic and semiconductor nanoparticles the could serve as nanoscaffolds or nanoscaffold coatings while maintaining bonding properties that are amenable to the linking of sensor molecules.

Satellite Contamination Materials Program (collaborator:  Professor Ned Ianno, UNL Department of Electrical Engineering) -- funding from NASA.  It is well known that out-gassing of epoxies and other organic components produces effluents that, when exposed to VUV and UV light, deposit onto the satellite.  This can significantly shorten the lifetime of satellite solar cells and other electronic components.  Professor Ianno and his group at UNL have established a cryo-pumped chamber that contains 3 effusion cells and several quartz crystal microbalances that can be used to measure impingement and deposition rate of these materials while simulating orbital conditions.  SENRG's role in this project is the Raman and infrared spectroscopy analysis of the deposited materials.

Raman Spectroscopy Studies of Transition-Metal Doped CuInSe₂ Compounds of Interest for Magnetic and Thermoelectric Properties (collaborator:  Professor Jennifer Aitken, Duquesne University).   Doping of CuInSe₂ with transition metals such as manganese introduces crystal lattice disorder that affects magnetic and thermoelectric properties.  This disorder affects lattice vibrational energies that can be monitored by Raman spectroscopy.

SENRG Personnel

Current Undergraduate Research Students: 

Laura Slaymaker
Matt Jensen
Thomas Webber
Nathan Hoffman
Loany Fajardo
Jesse Lange
Kirsten Lipps

Former Group Members:
Jiri Olejníček (post-doc) -- Academy of Sciences of the Czech Republic, Institute of Physics 

Chelsey Neville -- grade 7-12 science teacher, Elwood, NE 

Matt Ingersoll -- graduate school plans 

Megan Schliefert -- physician assistant school, University of Nebraska Medical Center 

David Paprocki -- nursing school, University of Nebraska Medical Center 

Ashley Vandeventer -- chemistry teacher, Omaha Burke High School, Omaha, NE 

Maurice Chessmore -- finishing UNK undergraduate degreeBritni Hervert -- finishing UNK undergraduate degree 

Andrea Martinez-Skinner -- graduate school, University of Nebraska Medical Center
Ty Haussler -- medical school, University of Nebraska Medical Center 

Ruth Udey -- graduate school, Michigan State University
Nobutoshi Ota -- graduate school, University of Illinois 

Peter Longo -- dental school, University of Nebraska-Lincoln
Caleb Laue -- officer and combat engineer, U.S. Army
Tony Fitch -- graduate school, California Institute of Technology