A multidisciplinary research team is developing more efficient and environmentally friendly processes to build light-emitting diodes with the help of the Canadian Light Source (CLS) at the University of Saskatchewan.
Dr. Simon Trudel, professor in chemistry at the University of Calgary and director of the university’s Nanoscience Program, said his team has been studying ways to use amorphous materials to build better “optoelectronic devices” such as organic photovoltaic cells or organic light-emitting diodes (OLEDs), which make possible digital display TV screens, computer monitors and smartphones.
By using a technique called X-ray Absorption Spectroscopy (XAS) at the CLS, Trudel’s team was able to precisely examine the structure of the materials they were experimenting with to create more efficient electronic cells.
Trudel’s team focused on one of the interior layers of the diode called the hole-transport layer, which regulates the movement of electrons — and electrical energy — in a device. They identified an amorphous vanadium oxide compound that could be used for the hole-transfer layer but did not require the standard-but-intense heat treatments to crystallize the material.
“What we’ve found is that we use a very simple method where we … just coat it onto the surface of our device,” Trudel said. When comparing their method to standard heat treatment, “we found there was no absolutely no advantage, and actually a slight device degradation, by heating up the material.”
The research was recently published in the journal Chemistry of Materials.
With the powerful CLS beamline tools, Trudel’s team was able to determine if the easily-applied amorphous vanadium oxide functioned as a hole-transport layer at practically the same level as commercially-available devices. “We really need these specialized tools to be able to understand the local structure around our material.”
Trudel said he hopes using vanadium oxide as a faster, cheaper and more efficient method of building electronic devices could lead to new breakthroughs with amorphous materials.
“This type of work is really opening up the scope of materials that can be made, and recognizing they can be functional materials. We’re expanding the realm of applications we can have with these materials.”
The Canadian Light Source (CLS) is a national research facility of the University of Saskatchewan and one of the largest science projects in Canada’s history. More than 1,000 academic, government and industry scientists from around the world use the CLS every year in innovative health, agriculture, environment, and advanced materials research.
The Canada Foundation for Innovation, Natural Sciences and Engineering Research Council, Canadian Institutes of Health Research, the Government of Saskatchewan, and the University of Saskatchewan fund CLS operations.