Efficient, Robust and Soluble Electron Transport Polymers

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

NON-TECHNICAL SUMMARY: Robust, reliable and flexible devices/circuits could be transformational for industries ranging from healthcare and environmental quality to energy and security. To attain this vision, new materials that can effectively transport charges are needed. In this regard, polymers that transport electrons are especially challenging. This proposal aims to design and synthesize new molecular structures that will not only readily transport electrons, but also be compatible with low-cost fabrication techniques. The research will impact a range of electronics technologies that are the mainstay of our society. Also, students will realize benefits from the multidisciplinary nature of the program. All students participating in this program will be cross-trained and, where necessary, will further expand their knowledge and experience through additional collaborations. They will develop leadership skills and have access to professional development workshops through participation in the Georgia Tech Polymer Network-Student Association. The PI is committed to diversity in her recruiting, education and training activities. TECHNICAL SUMMARY: Polymeric semiconductors have a number of advantages that derive from their inherent flexibility, solubility, and low temperature processability. Such competitive characteristics allow for the implementation of pi-conjugated polymers in low-cost, light-weight and large-area flexible optoelectronics. The application space ranges from simple transistor devices to photovoltaics for energy conversion, to light emitting diodes, to thermo-electrics and sensors. Ubiquitous availability of such devices will contribute the nation's needs in healthcare, environmental quality, energy and security. To enable the range of envisioned devices, both hole and electron transporting materials are required. Among these, polymers that exhibit electron transport characteristics are much more limited in their availability due to poor oxidative stability and high sensitivity to moisture. This study will identify polymer architectures having extended pi-conjugation to maintain a low bandgap, a low HOMO level for enhanced stability, and effective pi-pi intermolecular interactions to improved charge transport performance. The investigation will explore alternative alkyl side chains for their ability to solubilize targeted polymers in common organic solvents, synthesize both homopolymers and donor-acceptor architectures to tune HOMO/LUMO energy levels, characterize targeted materials via spectroscopic, microscopic and electrical methods to identify significant materials structure-processing-property parameters, and fabricate field effect transistor, photovoltaic and thermo-electric devices to evaluate the impact of the proposed approach. Key, synthetically accessible molecular components will be identified that will provide for an extension of semiconducting polymer pi-conjugation length allowing for the orientation and alignment that are an imperative for charge transport. The studies will identify efficient, robust, soluble electron transport polymer materials for flexible electronics applications.