OSU engineers figure out the physics behind photonic sintering of nanoparticles
The aim is to manufacture thin films for photovoltaics, electronics.
Engineers at Oregon State University (OSU; Corvallis, OR) have made a fundamental breakthrough in understanding the physics of photonic sintering, or the light-induced fusing of nanoparticles to form a solid, functional thin-film.1 Such films could lead to advances in photovoltaic cells, flexible electronics, various types of sensors, which could be printed onto something as simple as a sheet of paper or plastic.
Photonic sintering has the possible advantage of higher speed and lower cost compared to other technologies for nanoparticle sintering.
In the new research, OSU experts discovered that previous approaches to understand and control photonic sintering had been based on a flawed view of the basic physics involved, which had led to a gross overestimation of product quality and process efficiency.
Based on the new perspective of this process, researchers now believe they can create high quality products at much lower temperatures, at least twice as fast, and with 10 times more energy efficiency.
“Photonic sintering is one way to deposit nanoparticles in a controlled way and then join them together, and it’s been of significant interest,” says Rajiv Malhotra, an assistant professor of mechanical engineering in the OSU College of Engineering. “Until now, however, we didn’t really understand the underlying physics of what was going on. It was thought, for instance, that temperature change and the degree of fusion weren’t related – but in fact that matters a lot.”
A lower-temperature process
With the concepts outlined in the new study, the door is open to precise control of temperature with smaller nanoparticle sizes. This allows increased speed of the process and high quality production at temperatures at least two times lower than before. An inherent “self-damping” effect was identified that has a major impact on obtaining the desired quality of the finished film.
Products that could evolve from the research, Malhotra says, include solar cells, gas sensors, radio-frequency identification tags, and a wide range of flexible electronics. Wearable biomedical sensors could emerge, along with new sensing devices for environmental applications.
OSU researchers will work with two manufacturers in private industry to create a proof-of-concept facility in the laboratory as the next step in bringing this technology toward commercial production.
1. William MacNeill et al., Nature Scientific Reports (2015); doi: 10.1038/srep14845