Materials Science Research Lecture

***Refreshments at 3:45pm in Noyes lobby

Abstract:
Low-temperature plasmas are complex systems characterized by a non-equilibrium between free electrons, with typical temperatures in the 1-5 eV range, and heavy species that remain closer to room temperature. They are ubiquitous in the semiconductor industry, with the development of the reactive ion etching process enabling the miniaturization of the transistor and the booming of information technology. Despite their maturity, low-temperature plasmas are being heavily researched for multiple new potential applications. This talk will discuss two examples that hold great promise in terms of societal impact.

The first example is the use of low-temperature plasma to drive heterogeneous reactions on catalyst surfaces. This broad area is commonly referred to as "plasma catalysis", and it promises to open a pathway toward the electrification of the chemical industry. This field is characterized by a persistent lack of understanding of the fundamental, microscopic-level aspects of the plasma-induced activation pathways. We have recently completed a study in which we have exposed a platinum surface, saturated with chemisorbed CO, to a simple argon plasma and observed a significant reduction in CO adsorption energy. In-situ FTIR measurements, in combination with DFT calculations, suggest that plasma-induced surface charging and electric fields strongly decrease the CO adsorption energy. This example highlights the uniqueness of plasma activation compared to thermally or light-driven catalysis.

The second example discusses the use of low-temperature plasmas for the production of novel functional materials. While the formation of dust in processing plasmas was first seen as a major problem, the community quickly realized that these systems can grow nanoparticles that are difficult or impossible to achieve using other techniques. We will in particular discuss the use of plasma-produced, ultra-small silicon particles for applications in lithium-ion batteries. The small size and the narrow size distribution of plasma-produced nanoparticles enable highly stable battery materials without the need for complex nanostructured designs. The simplicity of this approach makes it promising for the inherently large-scale battery application space.

More about the Speaker:

Prof. Lorenzo Mangolini received his Ph.D. in Mechanical Engineering from the University of Minnesota, Minneapolis in 2007. After a brief experience in industry, he joined the Mechanical Engineering Department and the Materials Science and Engineering Program at UC Riverside in 2010. His broad interests are centered on the use of low-temperature plasmas for the production of novel functional materials, and most recently for the electrification of the chemical manufacturing industry. He is a recipient of the NSF Career Award and the DOE Early Career Award. He is the co-founder of SiLi-ion Inc., a start-up bringing plasma-produced materials to the lithium-ion battery market.