Polymeric and Molecular Materials for Advanced Organic Electronics.

摘要

During the project period, we made strong progress in: (I) organic semiconductors, (2) gate dielectrics, and (3) fundamental studies of charge transport. In (1), we expanded our understanding of the architectural and electronic structure requirements for n-type semiconductors and the role grain boundaries play in transport. To accomplish this, we developed new synthetic routes to processable small molecules and polymers, and characterized/optimized structural, electronic, and processing properties. In (2), we expanded the SAND (self-assembled nanodielectric) concept to vapor-deposited (V-SAND) and to spin- coated. printable variants. All have excellent dielectric and insulating properties, a remarkable ability to minimize trapped charge between thin film transistor dielectric and semiconductor layers, and because of the high capacitances, lowe red transistor operating voltages. These characteristics enable many new types of devices with outstanding performance, such as transparent and flexible transistors. In (3), we showed via variable-temperature studies that transport mechanisms involve multiple trapping and release mechanisms which are sensitive to the semiconductor film processing and the gate dielectric.