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!
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy