MSE 520: Seminar Series

π–Conjugated organic/polymer materials exhibit widespread applications in organic electronics and bright future for wearable electronics and bioelectronics due to their combining the electrical/optical behaviors of metals or semiconductors with the properties typical of plastics to have the possibility of fabricating devices on large-area, light-weight and flexible substrates by printing and coating technologies. In order to achieve high-performance organic electronic devices such as transistors and solar cells, our strategy is to simultaneously optimize materials design and synthesis, molecular self-assembly, additive processing, and interface/device engineering. Firstly, highly ordered π–conjugated molecular self-assembled monolayer (SAMs), single or bundled molecules with controlled conformation, location, environment, and orientation on Au surfaces have been constructed to allow systematic monitoring and harnessing of molecular electronic properties, photochemical reactions and photocurrent/photoconductance generation at a molecular level through scanning tunneling microscopy (STM) and Photon-STM measurements. Secondly, spin-cast, micro-contact printed and/or self-assembled molecular interface, monolayer dielectrics and supramolecular semiconductors have been studied to realize high-performance low-power transistors. Lastly, high-performance printable polymer and perovskite solar cells have been demonstrated through utilizing n-type interfacial materials such as C60-based ones. These interlayers serve multiple functions to affect the photoinduced charge transfer at the interface resulting in reduced recombination of charges and passivation of inorganic surface trap states, improve the exciton dissociation efficiency at the polymer/TiO2 or ZnO interface as well as a template to influence the overlayer bulk heterojunction distribution of phases, morphology and crystalline domains leading to better charge selectivity.

Hong Ma is a Research Associate Professor in the Department of Materials Science & Engineering, University of Washington. He received his PhD in 1997. After graduation, he had worked as a visiting scientist for 2.5 years in the Department of Chemistry, Northeastern University, Boston. In 2000, he moved to the Department of Materials Science & Engineering, University of Washington. He started with a position of research associate, then research scientist, research assistant professor to research associate professor. His research expertise is in the areas of organic/polymer materials/devices, molecular self-assembly and additive processing for renewable energy, flexible electronics, photonics and bionanotechnology. As PI, Co-PI or group leader, he has participated in more than ten interdisciplinary research programs and centers funded by NSF, DOE, DOD and NIH. He has published 108 refereed papers and 41 proceedings. Total SCI citations exceed 8,800 times (h-index: 46). Two US patents have been licensing to high-tech companies. He has been serving as an editorial board member of six journals, and a technical program committee member for several international conferences.