Solution-based inorganic process could drive more efficient electronics and solar devices
The yield so far is small, but chemists at the University of Oregon have developed a low-energy, solution-based mineral substitution process to make a precursor to transparent thin films that could find use in electronics and alternative energy devices.
A paper describing the approach is highlighted on the cover of the July 21 issue of the journal Inorganic Chemistry, which draws the most citations of research in the inorganic and nuclear chemistry fields. The paper was chosen by the American Chemical Society journal as an ACS Editor's Choice for its potential scientific and broad public interest when it initially published online.
The process described in the paper represents a new approach to transmetalation, in which individual atoms of one metal complex -- a cluster in this case -- are individually substituted in water. For this study, Maisha K. Kamunde-Devonish and Milton N. Jackson Jr., doctoral students in the Department of Chemistry and Biochemistry, replaced aluminum atoms with indium atoms.
The goal is to develop inorganic clusters as precursors that result in dense thin films with negligible defects, resulting in new functional materials and thin-film metal oxides. The latter would have wide application in a variety of electronic devices.
"Since the numbers of compounds that fit this bill is small, we are looking at transmetelation as a method for creating new precursors with new combinations of metals that would circumvent barriers to performance," Kamunde-Devonish said.
Components in these devices now use deposition techniques that require a lot of energy in the form of pressure or temperature. Doing so in a more green way -- reducing chemical waste during preparation -- could reduce manufacturing costs and allow for larger-scale materials, she said.
"In essence," said co-author Darren W. Johnson, a professor of chemistry, "we can prepare one type of nanoscale cluster compound, and then step-by-step substitute out the individual metal atoms to make new clusters that cannot be made by direct methods. The cluster we report in this paper serves as an excellent solution precursor to make very smooth thin films of amorphous aluminum indium oxide, a semiconductor material that can be used in transparent thin-film transistors."
Transmetalation normally involves a reaction done in organic chemistry in which the substitution of metal ions generates new metal-carbon bonds for use in catalytic systems and to synthesize new metal complexes.
"This is a new way to use the process," Kamunde-Devonish said, "Usually you take smaller building blocks and put them together to form a mix of your basic two or three metals. Instead of building a house from the ground up, we're doing some remodeling. In everyday life that happens regularly, but in chemistry it doesn't happen very often. We've been trying to make materials, compounds, anything that can be useful to improve the processes to make thin films that find application in a variety of electronic devices."
The process, she added, could be turned into a toolbox that allows for precise substitutions to generate specifically desired properties. "Currently, we can only make small amounts," she said, "but the fact that we can do this will allow us to get a fundamental understanding of how this process happens. The technology is possible already. It's just a matter of determining if this type of material we've produced is the best for the process."
The research was funded primarily through the National Science Foundation-funded Center for Sustainable Materials Chemistry (NSF grant CHE-1102637). It also was supported by the NSF-supported (grant CHE-0923589) NMR Spectroscopy Facility for analyses work done in the Center for Advanced Materials Characterization in Oregon (CAMCOR) located in the UO's Lorry I. Lokey Laboratories.
Co-authors with Kamunde-Devonish, Jackson and Johnson were former UO doctoral student Zachary L. Mensinger, now at the University of Minnesota at Morris, and Lev N. Zakharov of CAMCOR.
About the University of Oregon
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.
The paper (Transmetalation of Aqueous Inorganic Clusters: A Useful Route to the Synthesis of Heterometallic Aluminum and Indium Hydroxo—Aquo Clusters): http://pubs.acs.org/doi/abs/10.1021/ic403121r
Johnson faculty page: http://chemistry.uoregon.edu/fac.html?darren_johnson
Department of Chemistry and Biochemistry: http://chemistry.uoregon.edu/
Follow UO Science on Facebook: http://www.facebook.com/UniversityOfOregonScience
UO Science on Twitter: http://twitter.com/UO_RIGE
More UO Science/Research News: http://uoresearch.uoregon.edu
Note: The University of Oregon is equipped with an on-campus television studio with a point-of-origin Vyvx connection, which provides broadcast-quality video to networks worldwide via fiber optic network. In addition, there is video access to satellite uplink, and audio access to an ISDN codec for broadcast-quality radio interviews.
Jim Barlow | Eurek Alert!
Subcutaneous Administration of Multispecific Antibody Makes Tumor Treatment Faster & More Tolerable
01.07.2015 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Why human egg cells don't age well
01.07.2015 | RIKEN
New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions
A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...
A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...
The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...
On June 23, the second Sentinel mission was launched from the space mission launch center in Kourou. A critical component of Aachen is on board. Researchers at the Fraunhofer Institute for Laser Technology ILT and Tesat-Spacecom have jointly developed the know-how for space-qualified laser components. For the Sentinel mission the diode laser pump module of the Laser Communication Terminal LCT was planned and constructed in Aachen in cooperation with the manufacturer of the LCT, Tesat-Spacecom, and the Ferdinand Braun Institute.
After eight years of preparation, in the early morning of June 23 the time had come: in Kourou in French Guiana, the European Space Agency launched the...
25.06.2015 | Event News
16.06.2015 | Event News
11.06.2015 | Event News
01.07.2015 | Press release
01.07.2015 | Awards Funding
01.07.2015 | Physics and Astronomy