Barrier films, used in everything from food and drug packaging to consumer electronics and solar cells, help prevent your food from spoiling, help to preserve medication, and protect your electronics from damage due to exposure to air or a splash of water. Now a group of researchers in Georgia have developed a new way to produce better films using atomic layer deposition.
These are not the flimsy films of plastic that may seal a package of cookies. High-end barrier films that safeguard your phone's high-tech organic light-emitting diode (OLED) display from every whiff of oxygen or molecule of water vapor require higher performance transparent materials such as metal oxides.
Existing methods for manufacturing these high-performance barriers aren't perfect. Due to the way they're made, they often have small defects, resulting in tiny holes that let in water or oxygen. That's why Samuel Graham and his colleagues at the Georgia Institute of Technology have been exploring how to use atomic layer deposition to produce better barrier films. At the AVS 60th International Symposium and Exhibition, held in Long Beach, Calif. Oct. 27 – Nov. 1, Graham will discuss some of the latest developments in this effort.
Graham and his colleagues have created new barrier films that can protect electronics in very harsh environments – when submerged in salt water for months, for example.
"By creating such barrier films, we are able to extend the lifetime and reliability of electronic devices," Graham said. The new coatings can be used for electronics such as implantable biomedical devices, light-emitting diodes (LED) used in solid-state lighting and displays, solar cells, and organic electrochromic windows, which go from opaque to clear when a voltage is applied. Barrier films will play a large role in the development of many future electronic devices made with organic materials, Graham added.
How Atomic Layer Deposition Works
High-performance barrier films are usually made with techniques such as sputter deposition or plasma-enhanced chemical vapor deposition. In these methods, material is either “sprayed” onto a substrate or grown from a plasma, creating a thin layer that becomes the film. Although efficient and common in industry, these techniques often result in defects, requiring multiple coatings to create good barrier films.
With atomic layer deposition, the researchers have precise control down to the molecular level, allowing them to make thin, even films that have minimal defects. In this process, the researchers surround a substrate with a gas containing a particular metal atom like aluminum. The molecules of the gas attach themselves onto the substrate, forming a single layer of atoms. Next, excess gas is removed from the chamber and another gas is introduced that then oxidizes the metal, creating a metal oxide that's impervious to air or water. The process is repeated to reach the desired thickness, which is only about 10 nanometers. In contrast, films made with more conventional techniques are tens to hundreds of times thicker.
Companies are already developing and selling atomic layer deposition technology, Graham says. But for wide-scale commercial use, more work needs to be done to improve the technology, how fast the materials are deposited, and the chemical stability and mechanical reliability of the films.
Presentation TF+VT-WeM3, “Improving the Reliability of Electronics Using ALD Barrier Films,” is at 8:40 a.m. Pacific Time on Wednesday, Oct. 30, 2013.MORE INFORMATION ABOUT THE AVS 60th INTERNATIONAL SYMPOSIUM & EXHIBITION
This news release was prepared for AVS by the American Institute of Physics (AIP).ABOUT AVS
Catherine Meyers | Newswise
Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously
17.01.2017 | Sonderforschungsbereich 668
Manchester scientists tie the tightest knot ever achieved
13.01.2017 | University of Manchester
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction