Talk Title: Strategies to predict and control semiconducting polymers' dynamics*

 

Talk abstract: 

Organic semiconducting polymers were widely studied due to their unique optoelectronic and mechanical property. They are the key component in various functional electronic devices, such as organic photovoltaic devices, flexible displays, wearable sensors, neuromorphic computing, and more recently bioelectronics. Despite tremendous progress were made in improving the charge carrier mobility and optimizing energy bandgap, the conjugated polymer's physical property was not widely studied such as chain rigidly, molecular entanglement behavior, and glass transition phenomenon.  However, they are important for device stability, which is one of the major hurdles for polymer-based organic devices.  Polymer dynamics could play an important role in dictating overall chain mobility and morphology stability in the bulk heterojunction.

 

In my talk, I will provide an overview of our effort in studying the conjugated polymer's dynamics using a wide range of unique characterization tools, from thin-film to bulk. I will discuss the challenge associate with accurately measuring the glass transition temperature for rigid conjugated polymers.  I will discuss our approach to address this challenge using thin-film calorimetry and ellipsometry tools, as well as using molecular dynamic simulation and cheminformatic to accurately predict the glass transition temperature.  Lastly, I will discuss how dynamics could impact thin film morphology and device performance at different operation temperatures and should be carefully considered when design new polymers and devices.