Laser-Printed Organic Electronic Devices

Wake Forest University, Winston Salem NC

Investigators

Abstract

Organic electronic materials are versatile candidates for flexible electronics, but their adoption in consumer applications has been limited by the current processes which cannot yet deliver high-performance device arrays at manufacturing scale and low cost. This research project will address the challenge by using laser printing, a solvent-free, ubiquitous technology that has never been used to manufacture electronic devices. Here, film deposition is done from a melt phase, which allows a great control of its structural properties, while being environmentally friendly, fast, low-cost, high-throughput, and directly scalable to large-area electronics. By reducing the cost and complexity necessitated by elaborate, time-consuming traditional multistep manufacturing processes, results will accelerate the incorporation of organic opto-electronic devices in consumer technologies, and have a strong, positive impact on the US economy and society. In addition, this interdisciplinary research program offers training opportunities for graduate, undergraduate, and high school students, including nontraditional and underrepresented minority students, that will position them for leadership in scientific careers. This project will introduce an innovative technology for the manufacturing of organic opto-electronic devices and will answer critical questions about the structure, processing, and properties in laser printed organic devices. Specific objectives are: (1) to fabricate high-performance organic thin-film transistors (OTFTs) by laser printing consecutive layers of different electronic functionalities, (2) to advance the fundamental understanding of charge transport at laser printed organic semiconductor / contact and organic semiconductor / dielectric interfaces, and (3) to establish the relationship among semiconductor purity, microstructure and device performance. The research is structured in three phases. Phase 1 focuses on printing commercially available and custom modified organic semiconductors on conventional transistor structures. Phase 2 will build on this knowledge to develop OTFTs with printed semiconductors and polymer dielectrics, and electrodes defined by "Toner lithography", in which the laser printed patterns serve the role of shadow masks, subsequently removed by chemical treatment. In Phase 3 we will extend our findings to encompass all-laser-printed OTFTs.