CBE Seminar Series: Ying Diao, University of Illinois at Urbana-Champaign

Description

Assembly of Molecular Electronics: The Journey is More Important Than the Destination

Directed assembly, crystallization and microphase separation have played a central role in the development of modern electronics and energy materials. Recent years, printed electronics based on semiconducting molecular systems have emerged as a new technology platform that promise to revolutionize the electronics, clean energy and medical industry. In contrast to traditional electronic manufacturing that requires high temperature and high vacuum, these new electronic materials can be solution printed at near ambient conditions to produce flexible, light-weight, biointegrated forms at low-cost and high-throughput. However, it remains a central challenge to control the morphology of semiconducting molecular systems across length scales, due to their high conformational complexity and weak, non-specific intermolecular interactions. The significance of this challenge lies in the order of magnitude modulations in device performance by morphology parameters across all length scales. We believe that the key to addressing this challenge lies in understanding assembly pathways of electronic molecules. However, the existing literature has largely overlooked the journey of the molecules and focused only on the final morphology and electronic property in the solid-state. In our work, we show that “the journey is more important than the destination”. In the first example, we will discuss that understanding assembly pathways of conjugated polymers from solution to the solid state is a very powerful approach to control morphology from the molecular to the device scale for largely modulating electronic properties. In particular, we discover a previously unknown chiral liquid crystal mediated assembly pathways of achiral polymers which is sensitively modulated by polymer rigidity and printing flow. In a second example, we discover a cooperative polymorph transition pathway in single crystals that led to shape memory effect and superelasticity, paving the way to dynamic electronic materials.

Biography: Professor Diao is a Beckman Fellow, Dow Chemical Company Faculty Scholar, Lincoln Excellence for Assistant Professor (LEAP) Scholar at University of Illinois at Urbana-Champaign. She received her Ph.D. degree in Chemical Engineering from MIT in 2012. Her doctoral thesis was on understanding heterogeneous nucleation of pharmaceuticals by designing polymeric substrates. In her subsequent postdoctoral training at Stanford University, she pursued research in the thriving field of printed electronics. Diao group, started in 2015 at Illinois, focuses on understanding assembly of organic functional materials and innovating printing approaches that enable structural control down to the molecular and nanoscale. Her work has been frequently featured in scientific journals and news media such as the Science Magazine and Nature Materials. She is named to the MIT Technology Review’s annual list of Innovators Under 35 as a pioneer in nanotechnology and materials. She is also a recipient of NSF CAREER Award, 3M Non-Tenured Faculty Award and was selected as a Sloan Research Fellow in Chemistry as one of the “very best scientific minds working today”.