Team develops a microwave-assisted method for producing thin films

Dec 19, 2012

Growth of new materials is the cornerstone of materials science - a highly inter-disciplinary field of science that touches every aspect of our lives from computers and cell phones to the clothes we wear. At the same time, the energy crisis has brought the spotlight on synthesis and growth of materials for clean energy technologies, such as solar cells and batteries. However, researchers in these areas do not simply grow materials —they assemble the atoms and molecules that form so-called thin films on various substrates. It is a process that is highly complex, time-consuming and requires significantly high temperatures.

Now a multidisciplinary team at the University of Texas at Austin's Cockrell School of Engineering is using to assemble atoms into and grow them directly onto a substrate at significantly low temperatures. Results of the team's research conducted under the supervisions of Professor Arumugam Manthiram of the Texas Materials Institute and the Department of Mechanical Engineering and Professor Ali Yilmaz of the Department of Electrical and Computer Engineering, were published in the 19th December issue of Nature Publications' online, open-access journal Scientific Reports.

"Lowering the temperature at which thin films of relevant materials can be grown is one of the key focus areas of our research," said Reeja Jayan, postdoctoral fellow at UT-Austin and one of the lead authors of the paper. "With our microwave process, we could bring down temperatures to the level that enable us to grow materials on heat-sensitive surfaces, such as plastics, without damaging them."

The conventional methods for growing thin films typically require temperatures over 450 degrees Celsius for several hours and a cumbersome multi-step process. With the new method, thin films can now be grown at temperatures as low as 150 degree Celsius in less than 30 minutes, in a single step process, by using microwaves.

"With this new method, the process of thin film growth is made simple, wherein a solution containing the atoms of the desired material together with the substrate when exposed to microwaves can result in controlled film growth" said Professor Manthiram who supervised the experimental work. "Applications that could utilize this process include developing thin film batteries and that could be integrated into various devices like cell phones and tablets."

The team coats a conducting layer—similar to a metal—over their substrate, which serves like an antenna to attract the microwaves. The energy from the microwaves then coerces atoms from the solution to "self-assemble" into uniform thin films on the substrate. The local heating generated by the interaction between the microwaves and the metal layer serves to fuse the thin films to the substrate. It is an interaction so powerful that it makes the films strongly adhere to the substrate.

As part of the research, a computational model of the process was developed by the team, which helps better understand the physics behind the microwave interaction phenomena and provides them with predictive guidelines that can significantly reduce the number of experiments needed for future research. The team at UT-Austin has successfully demonstrated assembly of titanium oxide thin films at low temperatures, and is currently working toward the assembly of thin films in a variety of .

Explore further: 'Swiss cheese' membrane with adjustable holes

Related Stories

A cheaper way to produce nickel ferrite thin films

Sep 24, 2012

(Phys.org)—Researchers from North Carolina State University and the Georgia Institute of Technology have demonstrated a less-expensive way to create textured nickel ferrite (NFO) ceramic thin films, which can easily be ...

Magnetism in thin insulating films at room temperature

Oct 18, 2012

(Phys.org)—Researchers at the University of Twente's MESA+ Institute for Nanotechnology have succeeded in producing ultrathin films with an unusual combination of properties. At room temperature they do ...

Recommended for you

'Swiss cheese' membrane with adjustable holes

20 hours ago

A new membrane, developed by University of Twente scientists, can be made more or less porous 'on demand'. In this way, smart switching between 'open' and 'closed' is possible, which opens the way to innovative ...

Stretching oxides to modulate electrochemical properties

21 hours ago

Solid oxide fuel cells and solid oxide electrolysis cells hold the promise of highly efficient energy conversion, with lower pollution, to meet increasing global energy demands. But these devices need good ...

Developing the battery of the future

Oct 30, 2014

The search for the next generation of batteries has led researchers at the Canadian Light Source synchrotron to try new methods and materials that could lead to the development of safer, cheaper, more powerful, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.