Monday, February 11, 2019 - 1:30pm

Narrow bandgap conjugated small molecules and polymers are drawing significant attention in organic electronics, especially organic solar cells. An inevitable fact is that intrinsic advantages and disadvantages of these two classes of materials relevant to solution-processable photovoltaics are often contrary. In particular, small molecules possess structural monodispersity and higher crystallinity but with poorer film formation properties and lower thermal stabilities in the solid state compared to their polymeric counterparts. More importantly, solar cells based on small molecules are extremely sensitive to chemical impurities, whereas polymers are relatively more tolerant. The polydispersity of polymers significantly complicates the interpretation of solid state structure, resulting in poor practices towards satisfactory device application under real-world circumstances. This seminar will focus on how molecular frameworks can be designed to utilize some of the most important features of both polymers (e.g., film quality and thermal robustness) and small molecules (e.g., structural monodispersity and crystallinity) to enable organic electronic devices to be more tolerant to bulk composition, processing conditions, and environmental variability, considerations that are essential for practical flexible electronics.


Dr. Xiaofeng Liu


Principal Scientist Carbon Nanotube Technologies, LLC


NS2 2201