Printable electronics are created by spraying or printing inks containing conductive organic molecules onto a surface. The process is fast and much less expensive than current production techniques for items like solar cells or computer and television displays.
Additionally, it holds potential for amazing new applications: picture a wearable interactive display that needs no batteries. In the solar industry, the ability to print solar cells on giant roll-to-roll printing presses – like printing a newspaper – could make the technology much more affordable and mass marketable.
NC State physicists Dr. Harald Ade and Dr. Brian Collins, in collaboration with Dr. Michael Chabinyc at the University of California Santa Barbara, wanted to know why some processing steps resulted in better and more efficient devices than others. "Manufacturers know that some materials work better than others in these devices, but it's essentially still a process of trial and error," Ade says. "We wanted to give them a way to characterize these materials so that they could see what they had and why it was working."
To do that, Collins and Ade went to Lawrence Berkeley National Laboratory's Advanced Light Source (ALS). They developed a new technique which used the powerful X-rays from the ALS to look at how individual molecules within these materials organize. They found that the best performing devices were characterized by particular molecular alignments within the materials.
"In transistors, we found that as the alignment between molecules increased, so did the performance," Collins says. "In the case of the solar cells, we discovered alignment of molecules at interfaces in the device, which may be the key to more efficient harvesting of light. For both, this was the first time anyone had been able to really look at what was happening at the molecular level."
The researchers' results appear in the journal Nature Materials. Led by NC State and UCSB, an international collaboration of researchers from Lawrence Berkeley National Laboratory, Monash University in Australia, and University Erlangen-Nuremberg in Germany contributed to the work.
"We're hoping that this technique will give researchers and manufacturers greater insight into the fundamentals of these materials," Collins says. "Understanding how these materials work can only lead to improved performance and better commercial viability."
The research was funded by the Department of Energy, National Science Foundation through the American Reinvestment and Recovery Act, and Department of Education. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy.
Note to editors: Abstract follows.
"Polarized X-ray scattering reveals non-crystalline orientational ordering in organic films"
Authors: B. A. Collins, H. Yan, E. Gann, H. Ade, North Carolina State University; J. E. Cochran, M. L. Chabinyc, University of California, Santa Barbara; C. Hub, R. Fink, Physikalische Chemie and ICMM, University Erlangen-Nuremberg, Erlangen, Germany; C.Wang, Advanced Light Source, Lawrence Berkeley National Laboratory; T. Schuettfort, University of Cambridge, U.K.; C. R. McNeill, Monash University, Victoria, Australia
Published: April 15th 2012 in Nature Materials
Abstract: Molecular orientation critically influences the mechanical, chemical, optical and electronic properties of organic materials. So far, molecular-scale ordering in soft matter could be characterized with X-ray or electron microscopy techniques only if the sample exhibited sufficient crystallinity. Here, we show that the resonant scattering of polarized soft X-rays (P-SoXS) by molecular orbitals is not limited by crystallinity and that it can be used to probe molecular orientation down to size scales of 10 nm. We first apply the technique on highly crystalline small-molecule thin films and subsequently use its high sensitivity to probe the impact of liquid-crystalline ordering on charge mobility in polymeric transistors. P-SoXS also reveals scattering anisotropy in amorphous domains of all-polymer organic solar cells where interfacial interactions pattern orientational alignment in the matrix phase, which probably plays an important role in the photophysics. The energy and q-dependence of the scattering anisotropy allows the identification of the composition and the degree of orientational order in the domains.
Tracey Peake | EurekAlert!
New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University
Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
23.06.2017 | Physics and Astronomy
23.06.2017 | Physics and Astronomy
23.06.2017 | Information Technology